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Application Form: Import or Manufacture a Persistent Organic Pollutant under section 31 of the HSNO Act 1996

APPLICATION FORM CONTAINMENT

www.epa.govt.nz

Completing this form

Use this form to apply for a containment approval if you are importing or manufacturing a persistent organic

pollutant (POP) to be used as an analytical standard or for research in any laboratory.

If you need to use a POP for any other purpose, contact the Environmental Protection Authority (EPA) first.

The risks associated with the life cycle of POPs are well understood. We have approved a standard set of controls

for POPs that are being used for analytical standards or for research in a laboratory, to ensure that users of the

substances comply with the requirements of the Stockholm Convention on POPs. For more information on the

Convention, please refer to the HSNO Act.

• Substances that are POPs are listed in Schedule 2A of the Hazardous Substances and New Organisms

(HSNO) Act 1996.

• You can use this form to apply for more than one POP.

• Any extra information you supply that does not fit in the application form must be clearly labelled and cross-

referenced in an appendix. Commercially sensitive information must also be attached as a separate appendix.

• The fee for this application may be found on our website: www.epa.govt.nz.

• If you need help to complete this form, our staff can you help you at any time. Please call +64 4 916 2426 or

email [email protected].

OFFICE USE ONLY

Application code Date received

http://www.epa.govt.nz/

mailto:[email protected]

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Application for Approval of a Persistent Organic Pollutant in Containment

April 2013 EPA0189

1. Applicant details

Name of organisation: University of Auckland

Phone:

Email:

Postal address: in New Zealand

Street number and name:

Suburb:

Physical address: if different from postal address

Contact person This person should have sufficient knowledge to respond to queries; and either have the authority to make decisions (that relate to processing the application) on behalf of the applicant, or have the ability to go to the appropriate authority.

Name:

Phone:

Email:

Postal address: in New Zealand

Street number and name:

Suburb:

Town/city:

Post code:

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2. Type of application Complete the list below by ticking all the boxes that apply.

I am applying to use small amounts of any POP as an analytical standard. I am applying to research a POP, but only in a laboratory.

I want to import the substance(s) only. I want to manufacture the substance(s) only. I want to import and manufacture the substance(s). The substances were imported or manufactured before the commencement of the Stockholm Convention amendment to the HSNO Act.

Manufacturing If you want to manufacture the substance, explain the proposed processes – as well as any alternatives. You need to provide enough information to show whether there are likely to be any hazardous by-products of the process. N/A - import only

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3. Information on the substance(s) All information that is considered commercially sensitive must be attached as an appendix and marked ‘Confidential’. The application form should be cross-referenced to the appendix, and should also be able to be read as a stand-alone document (which will be publicly available).

The POP(s) is currently held in a laboratory.

I am applying to import/manufacture the POP(s) as a one-off.

I am applying to import/manufacture the POP(s) in an ongoing way. (Your laboratory will be required to notify the EPA at the time of each new import/manufacture, with information on the quantities and nature of the substance(s) concerned.)

Identification Provide details of the amount of each POP your laboratory currently holds, and/or intends to import/manufacture in the future.

Substance CAS No. Held in laboratory New import New manufacture

Amount (mg) Max amount per year (mg) Max amount

per year (mg)

Aldrin 309-00-2 50,000

Alpha hexachlorocyclohexane 319-84-6 50,000

Beta hexachlorocyclohexane 319-85-7 50,000

Chlordane 57-74-9

Chlordecone 143-50-0

DDT 50-29-3 50,000

Dieldrin 60-57-1 50,000

Endrin 72-20-8 50,000

Heptachlor 76-44-8

Hexabromobiphenyl 36355-01-8

Hexabromodiphenyl ether and heptabromodiphenyl ether

Hexachlorobenzene 118-74-1 50,000

Lindane 58-89-9 50,000

Mirex 2385-85-5 50,000

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Pentachlorobenzene 608-93-5 50,000

Perfluorooctane sulfonic acid; its salts 1763-23-1 50,000

Perfluorooctane sulfonyl fluoride 307-35-7

Perfluorooctanic acid 335-67-1 50,000

Technical endosulfan and its related isomers

115-29-7

959-98-8 33213-65-9

50,000

Tetrabromodiphenyl ether and pentabromodiphenyl ether

Toxaphene 8001-35-2 50,000

Polychlorinated biphenyls - 50,000

Polychlorinated dibenzodioxins - 50,000

Notes 1. The selected POPs in the list above will be imported in the first instance. The University may wish to import additional POPs in the next 4-5 years. EPA approval will be sought prior to importing any additional POP substance.

2. The above masses are maximum quantities only to be imported per annum for the purposes of seeking approval. Typical imports are likely to be in the range of 10 mg to 25 grams (as outlined below***), dependent on availability. This will enable a suitable number of experiments (10-15 per compound) for proof of principal.

3. Aldrin (250 mg); α-Hexachlorocyclohexane (100 mg); β-Hexachlorocyclohexane (100 mg); DDT (5 g); Dieldrin (100 mg); Endrin (250 mg); Hexachlorobenzene (1 g); Lindane (5 g); Mirex (100 mg); Pentachlorobenzene (5 g); Perfluorooctane sulfonic acid (10 g); Perfluorooctanic acid (25 g); Endosulfan (250 mg); Toxaphene (250 mg); Polychlorinated biphenyls (1 g); Polychlorinated dibenzodioxins (10 mg).

4. Civil and Environmental Engineering propose to import analytical standards for Perfluorooctane sulfonic acid for a closely related project involving analysis and investigation of possible methods of remediation of PFOS contamination of ground and surface water using oxidation (see below).

Lifecycle of the chemical Provide information on what will happen to each substance throughout its whole life, from its introduction into New Zealand, its uses, through to disposal. The level of information provided needs to reflect the containment character of the application, but should nevertheless cover the whole lifecycle of the substance(s) – for example, from import/ manufacture, transport, storage and use, through to disposal. You should also indicate whether any measures may be required in addition to the standard controls approved for these substance(s).

The purpose of importing and storing the aforementioned POPs is purely for advanced research and development purposes at the School of Chemical Sciences. R&D is associated with a novel contaminant degradation technique known as high energy ball milling. This technique can effectively breakdown contaminant molecules into inert by-products, and has been involved in lab-scale and full-scale demonstrations globally. This treatment method is seen a ‘green’ solution to hazardous waste issues, due to its simple approach to degrading chemical contaminants and no requisite for toxic solvents or large energy input.

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A closely related project in the Civil and Environmental Engineering involves analysis and development of potential novel methods of remediation of PFOS contamination of ground and surface water using oxidation.

The research will be conducted entirely within a contained modern chemistry laboratories which will meet the requirements of HSNO s33 Exempt laboratory, Part 18 of the Health and Safety at Work (Hazardous Substances) regulations, 2017as well as AS/NZS 2960.

The following appendices are included in this application:

Appendix 1 - Controls in place for the use of POPs for research in the chemistry laboratories at The University of Auckland

Appendix 2 - Critical review of ball milling techniques for degradation of POPs.

Appendix 3 - Extract of UN-commissioned assessment of full-scale ball milling treatment system for dioxin-contaminated soil in Vietnam (the complete report can be provided on request).

Appendix 4 - List of references showing the effectiveness of high energy ball milling for treating POPs in various media.

Appendix 5 - Handling Persistent Organic Pollutants for Advanced Research and Development: A Laboratory Operating Procedure.

Import / Transport

- POPs will be sourced locally in New Zealand or imported from internationally recognised laboratory chemical manufacturers and distributors, i.e. Sigma Aldrich.

- Best practice will be exercised in handling of the substances in accordance with HSNO regulations as described in Appendix 1.

- Once delivered to the University of Auckland’s School of Chemical Sciences and Civil and Environmental Engineering Laboratories, POPs will not leave the laboratory and will be securely stored as described below.

Storage

- POPs will be stored in sealed containers within labelled laboratory storage areas that will be dedicated to

storage of these compounds and any other reagents or waste material containing POPs used in the

project. This will ensure that all the laboratory reagents used in this project are kept separate, can be

easily identified and any relevant measurements made and documented prior to disposal.

Use

- POPs will be used for research only. To mitigate risk, all personnel handling POPs will be provided with all relevant information about the POPs they are using, as advised in the Hazardous Substances Regulations 2001. Additionally, specific training will be provided for degrading POPs by high energy ball milling. In the case of analysis of PFOS contamination of surface water the small amounts of PFOS will remain under the control of the Principal Investigator.

- The primary objectives are to verify the kinetics of POP breakdown and to determine the mechanisms behind contaminant breakdown which will inform full-scale applications, i.e. soil remediation, hazardous waste degradation.

- Small amounts of POPs (microgram to milligram range) will be spiked into silica (gel or fine quartz sand) and placed in a fully-sealed and encapsulated grinding jar with metal ball bearings. Milling jars range from 10 mL to 50 mL and are made from hardened steel, stainless steel, or tungsten carbide. The jar will be securely fixed in a specialist planetary ball mill and the internal matrix will be crushed by the metal ball

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bearings as the jar spins within the ball mill. Samples will be collected for analysis prior to, during, and after milling to determine intermediate and final breakdown products.

- Milling vessels and balls will be cleaned in accordance with the standard procedure outlined below:

1. Following a complete milling run, the residual matrix will be stored in a discrete hazardous waste container.

2. The milling jar, lid, and balls will be cleaned of any solid residue with wipes moistened with hexane and then cleaned with wipes moistened with deionised water. All spent wipes will be stored in a separate hazardous waste container.

3. The jar will then be 1/3 filled with clean quartz sand or silica and subjected to a 1 hour ‘cleaning run’. The resultant matrix will be sampled and analysed by Gas Chromatography Mass Spectroscopy and Fourier Transform Infrared Spectroscopy to determine the presence of remaining POPs.

4. If POPs are detected, then steps 1 to 3 will be repeated until no POPs remain following a ‘cleaning run’.

In the case of surface water analysis the analytical standard will remain the lab and any waste will be sent out for appropriate and environmentally safe disposal via approved chemical waste contractors

- ‘Real-world’, low level POPs-contaminated soil (≤1000 grams) may be imported from recognised local and overseas authorities and agencies over time to test proof of principle on laboratory-scale ball mills. To date, interested parties include the United Nations Environment Programme, federal and local authorities, internationally recognised research institutions, and other university groups.

- There will be no environmental discharge to air, land, or water at any time during trials and experiments.

Disposal

- The type of research to be conducted inherently leads to the degradation of POPs via a non-incineration and ‘environmentally-friendly’ pathway.

- It is envisaged that POPs will be destroyed by high energy ball milling over time and confirmed by specialist analysis at The University of Auckland, including Gas Chromatography Mass Spectroscopy, Nuclear Magnetic Resonance, Electron Paramagnetic Resonance, Fourier Transform Infrared Spectroscopy, and Raman Spectroscopy. PFAS contamination of Surface water will be analysed By Liquid Chromatography and tandem Mass Spectroscopy.

- Based on previous research, the residual POPs within the silica or soil matrix following milling will be less than 90% of the original concentration (100% POPs destruction in some cases). This application has taken a conscientious, and very conservative approach, by requiring environmentally sound disposal of all waste at an overseas location, via specialist hazardous waste contractors, in accordance with HSNO guidelines as outlined in the accompanying Standard Operating Procedure (Appendix 5; reference: UOA-SOP: Apr19).

- It is anticipated that relatively small amounts of solid and liquid waste would be produced during POPs research activities. Per annum rates are:

1. < 5 kg of low-level POPs solid waste.

2. < 24 L of chlorinated liquid waste.

- The SOP describes the procedures in place to safely import, handle, contain, and account for POPs and POPs-impacted material, i.e. tracking POPs and waste from import through to disposal.

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4. Information on the proposed containment system We have approved a standard set of controls for the use of persistent organic pollutants as analytical standards or for research in a laboratory (refer Appendix 1). You must provide sufficient information on how you propose to meet the requirements of these controls. Include information on how you intend to address each of the following issues, having regard to the controls listed in Appendix 1:

• Methods for preventing the escape of the contained hazardous substance and preventing the contamination of the facility

• Methods for excluding organisms from the facility or to control organisms within the facility

• Methods for excluding unauthorised people from the facility

• Methods for preventing unintended release of the substance by experimenters

• Methods for controlling the effects of any accidental release of the substance

• Inspection and monitoring requirements of the containment facility.

You also need to provide a management plan, attached as an appendix, which provides details of the containment proposed.

The POPs that are the subject of this application will be imported from specialist laboratory suppliers as analytical

grade chemicals in quantities typically less than 10 grams.

POPs will be stored in sealed containers within labelled laboratory storage areas that will be dedicated to storage

of these compounds and any other reagents or waste material containing POPs used in the project. This will

ensure that all the laboratory reagents used in this project are kept separate, can be easily identified and any

relevant measurements can be made prior to any disposal.

The work will be conducted within a modern chemistry laboratories in the School of Chemical Sciences and in Civil

and Environmental Engineering which have been designed and constructed to meet AS/NZS 2982:2010 and

complies with the containment requirements of:

• Code of Practice for University and CRI Exempt Laboratories (HSNO CoP 1/1)

• Part 18 of Health and Safety at Work (Hazardous Substances) Regulations, 2017

In particular all surfaces are impermeable to solvents and easily cleaned. Bench surfaces being Trespa Toplab

high pressure phenolic resin laminate which are chemical and heat resistant. Fume cupboards are designed and

installed to AS/NZS2243.8. Fume cupboards are tested annually by IANZ accredited testing agency to the same

standard.

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Access to these laboratories is controlled by swipe card access control preventing unauthorised access. The

electronic access controller can be door specific if required and lost cards can be deleted immediately to provide

high levels of confidence in the security system.

All waste material is stored separately (see above) and concentration of POPS will be measured and documented

so that documented empirical assessment is made. Any waste above thresholds set by National Environmental

Standard for the specific POP will be reprocessed until it meets the above standards or exported for destruction by

incineration overseas.

All laboratories in the School of Chemical Sciences and Civil and Environmental Engineering being HSNO s33

Exempt and HSWA Part 18 laboratories have a Laboratory Manager and a Person in Charge. The laboratories are

also subject to monthly internal monitoring in the form of a checklist which is posted at the laboratory entrance

ensure the laboratory meets and maintains minimum Part 18 requirements. It is proposed that this monitoring be

extended to encompass containment of POPs, so that any additional containment requirements stipulated in this

application are met and documented in an ongoing manner.

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5. Miscellaneous • Attach a glossary of scientific and technical terms used in your application. • Include any other information you consider relevant to your application, which is not already included.

HIGH ENERGY BALL MILLING OF POPS

1. INTRODUCTION

The degradation of Persistent Organic Pollutants (POPs) by high energy ball milling is underpinned by the fundamental principles of mechanochemistry. This field focuses on the change of substances that have been mechanically stressed, and the subsequent chemical and physical reactions which take place. There is a substantial body of evidence [1], from laboratory-scale to full-scale, which shows the degradation of all types of organic contaminant molecules by high energy ball milling.

Over the last 20 years, most of the research associated with ball milling as a degradation technique has looked at the destruction of organic contaminants to address soil remediation issues [1] High rates of POP degradation (>90%) have been observed at the laboratory scale [1][2][3], however there is limited information related to the mechanism(s) which lead to contaminant breakdown.

The objective of this ‘Factsheet’ is to summarise the application of ball milling technologies for degrading POPs and the need to further investigate the molecular breakdown mechanisms involved in the process.

2. MECHANOCHEMISTRY

Mechanochemistry is an emerging division of chemistry which explores changes in the molecular composition of substances that have undergone mechanical fractures or have been mechanically stressed; in other words, these are reactions activated by mechanical energy [4]. Although not focused on here, mechanochemistry is also associated with mechanical alloying or mechanochemical synthesis. These techniques are able to produce, amorphous alloys, nanocrystalline materials, and metastable crystalline alloys [5].

Major advantages to mechanochemical techniques include:

- Significantly lower power consumption relative to conventional thermal and plasma technologies.

- Final degradation by-products are inert for POPs, and can be re-used in civil engineering applications or disposed of safely at a local landfill. No secondary hazardous materials handling procedures are required.

- Completely scalable technology as evidenced by large-scale operational reactors (see Section 3 below).

- Vessels and reactors encapsulate all materials during the milling process, so in the event of any failures the matrix is effectively ‘trapped’, reducing any exposure pathways.

- No requisite for harmful additives or toxic solvents as required in chemical treatment.

- Simple operation, i.e. not requiring complex start-up and shutdown procedures.

- Low operating temperatures compared to plasma and incineration systems.

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The mechanisms involved in mechanochemical transformations tend to be complex and dissimilar to reactions observed in thermal, photochemical, or solvent processes. Some theories which account for the degradation of POPs include:

- Material fracture leading to the creation of highly reactive surfaces where contaminant molecules can settle, resulting in fragmentation into inert by-products.

- Creation of triboplasmas at the sub-microscopic deformation zone due to the large energy densities and friction at the point of collision.

Mechanochemistry has become an established method for grinding / milling and is utilised for metal mining and agricultural purposes, i.e. particle size reduction for ore and grains. Recently, ball milling has become an attractive option for POPs degradation as it is solvent-free and consumes less energy than standard processes, providing an effective and sustainable alternative to conventional solution-based and thermal-based techniques.

2.1 Reaction Sequence

High energy ball milling can provide the immense, indiscriminate mechanical force required to drive chemical reactions, resulting in deformations and an array of intramolecular and intermolecular alterations [4]. In the case of RBM, the ball-to-ball and ball-to-surface collision points are the major regions of chemical reaction initiation (Figure 1).

The reactions induced at the fracture point include radical formation, electron transfer, and electron sharing which can result in the formation and, in the case of the proposed study, the destruction of chemical bonds [5].

2.2 Milling Apparatus Mechanochemical reactors are often ball mills. Planetary ball mills are known as high energy mills as the ball speeds and collision forces observed are significantly greater than those seen in conventional mills which rely on gravity [6]. Planetary ball mills are particularly appropriate for laboratory-scale research due the minimal quantities of matrices and reagents required. Furthermore, the reaction models observed in laboratory-scale trials correlate well with results obtained from full-scale trials.

The planetary mill system is made up of a sun disc and a milling jar. Powerful centrifugal forces are generated as the sun disc rotates in one direction while the jar rotates in the opposite direction about its central axis (Figure 2). As the rotation of the milling jar and the sun disc are opposed, the centrifugal forces are alternately synchronised.

Figure 1. Collision Profile

1. Elastic Deformations

3. Fracture

2. Plastic Deformations

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Consequently, we can observe a grinding, sliding motion of the balls on the inner surface of the jar, as well as full-force collisions. The grinding, sliding motion results from the sun disc rotation. The full-force collisions are a product of the synchronised rotation of the jar and the disc which causes the balls to strike the opposing inner wall.

Optimal speed settings will differ from mill to mill and should be set at almost critical value in order for the balls to have the greatest collision force. Obtaining peak operation parameters of milling apparatus is often difficult. Influencing factors include milling speed, milling jar and milling matrix composition, ratio of ball mass to matrix, milling time, volume of free space in the jar, atmospheric conditions, temperature, and particle shape and size [7].

A Retsch PM-100 (Figure 3) planetary ball mill will be used as the mechanochemical reactor for the course of this project. Retsch states that “the extremely high centrifugal forces of the Planetary Ball Mills result in very high pulverisation energy.” Thus, the PM-100 offered the necessary mechanical energy input required to breakdown organic molecules. This mill is particularly suitable as a range of mill-speeds can be tested: reduced speeds allowed for analysis of POP breakdown products and possible intermediates.

2.3 POPs Degradation

POPs are resistant to environmental breakdown due to their chemical stability. Recently, the use of ball mills has become synonymous with mechanochemical destruction of POPs, especially for soil remediation purposes. Although POP degradation pathways are complex for high energy ball milling, most trials show high rates of

Figure 3. (a) Retsch PM-100 planetary ball mill; (b) Retsch milling jar; (c) Metal ball bearings.

Figure 2. Cross-section schematic of planetary ball mill.

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destruction, as presented in collaboration between Tsinghua University and Auckland University of Technology which reviewed of all significant research outputs to date [1]. This critical review revealed degradation rates between 99-100% for a wide range of POPs and organic contaminants subjected to mechanochemical conditions.

Among the most recalcitrant contaminants researched to date are polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and obsolete pesticides like dichlorodiphenyltrichloroethane (DDT) and polychlorinated dibenzodioxins (PCDDs) [2][8][9] .

During milling, POPs are dehalogenated and the remaining carbon skeleton is broken down to form an insoluble graphitic residue. The conversion can be accelerated by the presence of hard minerals. The primary end products of POPs degraded by high energy ball milling are:

- Amorphous carbon residues (graphitic carbon). - Inorganic halides and halogens sequestered in the powdered final matrix.

Furthermore, the reaction models discerned in the lab correlate well with results obtained from full-scale trials; conveying the scalability of the process and allowing for accurate predictions of destruction efficiency to be made.

3. FULL-SCALE VALIDATION & ASSESSMENT

High energy ball milling is an entirely scalable system that is entirely indiscriminate toward POPs and capable of degrading any organic contaminant to its base / elemental constituents.

Large-scale site clean-ups include projects conducted by Environmental Decontamination Ltd (EDL), a technology provider with substantial experience in the global contaminated land sector. This includes the remediation New Zealand’s most contaminated site at a former pesticide factory in Mapua, New Zealand [10][11]. Soil contaminated with Lindane, DDT, Dieldrin, and Aldrin was successfully treated to the remedial goals (Table 1).

Table 1. Mapua, New Zealand 2006.

Contaminant Untreated Soil (mg/kg) Treated Soil (mg/kg) Reduction (%)

Lindane 1.25 0.145 88

DDXa 717 64.8 91

Aldrin 7.52 0.798 89

Dieldrin 65.6 19.8 70

Notes: a. DDX includes DDT and its breakdown products DDE and DDD.

EDL carried out a full-scale soil decontamination demonstration at a former US airbase in Vietnam, commissioned by the UNDP. The trial built on experience gained at Mapua and other international projects, leading to successfully treating 150 tonnes of soil contaminated with Poly-Chlorinated Dibenzo-p-Dioxins and Dioxin-like Poly-Chlorinated Biphenyls; which are amongst the most recalcitrant / toxic anthropogenic chemicals (Table 2).

Table 2. Bien Hoa, Vietnam 2015.

Contaminant Untreated Soil (ng/kg TEQ) Treated Soil (ng/kg TEQ) Reduction (%)

PCDD/Fa 28,500.0 338.0 98.8

Dioxin-like PCBsb 15.9 0.4 97.4

Notes: a. PCDD/F = Poly-Chlorinated Dibenzo-p-Dioxins / -Furans b. PCBs = Poly-Chlorinated Biphenyls.

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The increased POP degradation rate observed in the Bien Hoa project compared to the Mapua project was most likely due to the evolution of EDL’s system during the projects (about 9 years). The UN’s technical report indicates that the system was in its fifth generation. POPs were broken down in a vibratory mill during the Mapua project, whereas POPs were broken down in a cascading, continuous, 4-reactor system during the Bien Hoa demonstration.

The final evaluation report for the Vietnam project (full report in Appendix 3):

“[High energy ball milling] is considered technically qualified for remediation applications on the large majority of PCDD/F contaminated soil likely to be encountered for even the most restrictive land use and as such should be considered in any commercial opportunities that arise including for pending remediation work at Bien Hoa without further demonstration of this type, and likewise would be candidate for POPs contaminated sites being addressed by the GEF globally.”

- UNDP Independent Technology Evaluation (2015) [12].

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4. Technology Applications Table 3. Environmental contaminants which high energy ball milling can effectively treat.

Waste Type Contaminant Scale of Application

Soil contaminated with POPs listed on the Stockholm Convention

(Annex A - C)

Aldrin Full scale

Chlordane Lab scale / In principle

Chlordecone Lab scale / In principle

Decabromodiphenyl ether Lab scale / In principle

DDT Full scale

Dieldrin Full scale

Endosulfan Lab scale / In principle

Endrin Full scale

Heptachlor Lab scale / In principle

Hexabromocyclododecane Lab scale / In principle

Hexabromobiphenyl Full scale

Hexachlorobenzene Lab scale / In principle

Hexachlorobutadiene Lab scale / In principle

α-Hexachlorocyclohexane Lab scale / In principle

β- Hexachlorocyclohexane Lab scale / In principle

Lindane Full scale

Mirex Lab scale / In principle

Octabromodiphenyl ether Lab scale / In principle

Pentachlorobenzene Lab scale / In principle

Pentabromodiphenyl ether Lab scale / In principle

Pentachlorobenzene Lab scale / In principle

Pentachlorophenol Lab scale / In principle

PFOS / PFOA Lab scale / In principle

Polychlorinated biphenyls Lab scale / In principle

Polychlorinated dibenzo-p-dioxins Pilot scale

Polychlorinated dibenzofurans Pilot scale

Polychlorinated naphthalenes Lab scale / In principle

Short-chain chlorinated paraffins Lab scale / In principle

Toxaphone Lab scale / In principle

Soil contaminated with organochlorine pesticides not listed on the Stockholm

Convention Generic organochlorine pesticides Lab scale / In principle

Soil contaminated with organophosphorus pesticides

Generic organochlorine pesticide Lab scale / In principle

Asbestos cement containing materials All asbestos types (amosite, chrysotile, crocidolite, etc.)

Pilot scale

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5. References

[1] Cagnetta, G., Robertson, J., Huang, J., Kunlun, Z., & Gang, Y. (2016). Mechanochemical destruction of halogenated organic pollutants: a critical review. Journal of Hazardous Materials, 313, 85-102.

[2] Birke, V., Mattik, J., & Runne, D. (2004). Mechanochemical reductive dehalogenation of hazardous polyhalogented contaminants. Journal of Materials Science, 39, 5111-5116.

[3] Cagnetta, G., Huang, J., Wang, B., Deng, S., & Yu, G. (2016). A comprehensive kinetic model for mechanochemical destruction of persistent organic pollutants. Chemical Engineering Journal, 291, 30-38.

[4] Meloni, P., Gianfranco, C., & Delogu, F. (2012). Specific reactivity of quartz powders during mechanical processing. Materials Research Bulletin, 47, 146-151.

[5] Beyer, M. K. & Clausen-Schaumann, H. (2004). Mechanochemistry: The Mechanical Activation of Covalent Bonds. Chemical Reveiws, 105, 8.

[6] Kano, J., Miyazaki, M., & Saito, F. (2000). Ball mill simulation and powder characteristics of ground talc in various types of mill. Advanced Powder Technology, 11, 3, 333-342.

[7] Suryanarayana, C. (2001). Mechanical alloying and milling. Progress in Materials Science 46, 184-193. DOI: 10.1016/S0079-6425(99)00010-9.

[8] Bellingham, T. (2005). The Mechanochemical Remediation of Persistent Organic Pollutants and Other Organic Compounds in Contaminated Soils. Auckland University of Technology.

[9] Nomura, Y., Fujiwara, K., Terada, A., Nakai, S., & Hosomi, M. (2012). Mechanochemical degradation of γ-hexachlorocyclohexane by a planetary ball mill in the presence of CaO. Chemosphere, 86, 228-234.

[10] USEPA Office of Superfund Remediation and Technology Innovation (2005). Reference guide to Non-Combustion Technologies for Remediation of Persistent Organic Pollutants in Stockpiles and Soil.

[11] USEPA National Service Centre for Environmental Publications (2007). Technology News and Trends, Issue 28.

[12] Cooke, R. J. (2015). GEF/UNDP Project on Environmental Remediation of Dioxin Contaminated Hotspots in Vietnam: Independent Expert Evaluation of Three Pilot/Laboratory Scale Technology Demonstrations on Dioxin Contaminated Soil Destrution from the Bien Hoa Airbase in Viet Nam. Commissioned by the UNDP.

Additional information attached as appendices.

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6. Summary of information for the public register The information provided in this section may be used in our public register of substances.

It will also be used to provide information for other government agencies (for example, the Ministry for the Environment, the Ministry of Health, or the Ministry of Business, Innovation and Employment), who will be notified of the application.

This information will be used to prepare the public notice of the application. For these reasons, applicants should ensure that this summary information does not contain any commercially sensitive material.

Name of the substance: Each substance on the Register must be identified by a unique name. Please provide a name for the substance(s) covered by this application. A maximum of 80 characters may be used – for example, POP standards laboratory X 2012 Base name: UoA POPs Group Aldrin UoA POP Group Aldrin Alpha-hexachlorocyclohexane UoA POP Group α-HCH Beta-hexachlorocyclohexane UoA POP Group β-HCH DDT UoA POP Group DDT Dieldrin UoA POP Group Dieldrin Endosulfan UoA POP Group Endosulfan Endrin UoA POP Group Endrin Hexachlorobenzene UoA POP Group HCB Lindane UoA POP Group γ-HCH Mirex UoA POP Group Mirex Pentachlorobenzene UoA POP Group Pentachlorobenzene Perfluorooctane Sulfonic Acid UoA POP Group PFOS Perfluorooctanic Acid UoA POP Group PFOA Polychlorinated Biphenyls UoA POP Group PCBs Polychlorinated dibenzodioxins UoA POP Group PCDDs Toxaphene UoA POP Group Toxaphene

Purpose of the application: This should include an abstract (in a maximum of 255 characters) giving information on the intended use of the substance and why an application is needed, based on its hazardous properties. Abstract: We intend to investigate effective treatment technologies using mechanochemical degradation for remediation of recalcitrant hazardous wastes. Importing raw standardised POPs is required to determine and quantify

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degradation mechanisms, which will directly inform potential industrial application downstream. Additional Information: The purpose of this application is to meet the regulatory requirement to import and store POPs at the University of Auckland’s School of Chemical Sciences. These substances will be used for academic research only; specifically related to the novel degradation of organic contaminants by high energy ball milling. The inherent chemical and physical characteristics of POPs (environmental stability, halogenation, toxicity) are specific to POPs themselves. Studying the breakdown of the selected POPs is necessary to determine the capabilities of ball milling technologies to effectively treat contaminated waste streams, i.e. contaminated soil, obsolete pesticide products, spent activated carbon from water treatment, etc. Furthermore, analysing the intermediate and final breakdown products of POPs will reveal the degradation pathway(s) and mechanism(s) involved in high energy ball milling, leading to a significant contribution to the environmental technology field. This would allow for better solutions to current hazardous waste issues associated with treatment, handling, and disposal.

Executive summary:

This application is for approval to import, or manufacture in containment, small amounts of the following persistent

organic pollutants for use as analytical standards or for research in a laboratory:

Aldrin Lindane (γ-HCH)

Alpha-hexachlorocyclohexane (α-HCH) Mirex

Beta-hexachlorocyclohexane (β-HCH) Pentachlorobenzene

Dichlorodiphenyltrichloroethane (DDT) Perfluorooctane Sulfonic Acid (PFOS)

Dieldrin Perfluorooctanic Acid (PFOA)

Endosulfan Polychlorinated Biphenyls (PCBs)

Endrin Polychlorinated dibenzodioxins (PCDDs)

Hexachlorobenzene (HCB) Toxaphene

Persistent Organic Pollutants are toxic and ecotoxic substances – for instance, they will trigger hazard

classifications in Classes 6 and 9 (see the HSNO (Classification) Regulations 2001). It is considered that the

principal risk arising from them is to the environment as a consequence of their persistence. However, it is noted

that any risks will be mitigated by the containment controls set by the EPA for these substances when used for the

prescribed purposes.

It is considered unlikely that any adverse environmental impact will occur from the use of the substances, given the

small quantities involved and given the controls that are in place to limit the likelihood of escape and control the

effects of any accidental release. All waste and by products will be analysed to quantify the success of the

treatment regime and provide a documented empirical assessment for any later disposal. Any waste above

thresholds set by National Environmental Standard for the specific POP will be exported for destruction by

incineration overseas.

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Safe handling procedures and health hazard information are provided in safety data sheets. The ongoing

requirements of HSNO s33 and HSWA Part 18 laboratories require that those in the laboratory and those handling

the laboratory are familiar with the hazards, use the correct PPE and ensure their exposure in minimised. It should

also be noted that the laboratories are designed and constructed to ensure containment and have local ventilation

controls to prevent exposure.

Furthermore, these substances will be used for academic purposes only, as part of a growing research theme

focused on developing treatment techniques for hazardous wastes streams, including POPs and POPs-impacted

material. The type of research to be conducted is focused on the degradation of POPs via a non-incineration and

environmentally-friendly pathway which can be up-scaled to meet the demands of industrial waste disposal which

may be useful for treatment of such wastes in NZ and globally. Therefore, this body of research is in the spirit of the

Stockholm Convention (2017), which explicitly promotes “appropriate research, development, monitoring and

cooperation pertaining to persistent organic pollutants”, as well as working toward the development and

implementation of environmentally sound technologies to address POPs and POPs-impacted material

domestically, as outlined by the Basel Convention (2014).

7. Applicant’s signature

I declare that to the best of my knowledge, the information contained in all sections of this application form, and supplied in support of this application, is true and accurate.

Name: Signature:

Date: 14 June 2019 (for this revision)

Applicant checklist

All parts of this form completed

Appendices attached

Fees enclosed - fees paid in October 2018

When you have completed this form, send by post to: The Environmental Protection Authority, Private Bag 63002, Wellington 6140 OR email to: [email protected]

Please allow 30 working days for processing.

mailto:[email protected]

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April 2013 EPA0189

Appendix 1: Controls applying to the use of POPs as analytical standards or for research in a laboratory

Interpretation

1. ‘Persistent organic pollutant’ (POP), ‘Laboratory’ and ‘Stockholm Convention’ have the meanings given in

section 2 of the Hazardous Substances and New Organisms Act (the Act).

2. ‘Passenger service vehicle’ has the same meaning as in the Transport Services Licensing Act 1989.

3. ‘Environmentally sound disposal’, in relation to a substance that is a persistent organic pollutant, means

disposal in accordance with directions given by the EPA in the New Zealand Gazette Issue no. 174, 22

December 2004, Hazardous Substances (Storage and Disposal of Persistent Organic Pollutants) Notice 2004.

‘Disposal in an environmentally sound manner’ has the same meaning as ‘environmentally sound disposal’.

General

4. This approval applies only to persistent organic pollutants approved in accordance with section 32 of the Act for

use as analytical standards or for research in a laboratory.

5. The use of persistent organic pollutants as analytical standards or for research in a laboratory shall comply with

the requirements of the management plan submitted by the applicant as part of the application under section 31

of the Act.

6. A laboratory that has approval to import or manufacture a POP for the approved purposes shall not sell, gift or

otherwise transfer the substance to another laboratory that does not have an approval under section 32 of the

Act for those substances; and, unless otherwise authorised by the EPA, shall not transfer the substance to any

other person unless such transfer is for the purpose of environmentally sound disposal.

7. This approval remains in place for five years.

8. There must be general compliance with the requirements of the Hazardous Substance (Exempt Laboratories)

Regulations, with specific regulations referred to below where relevant.

Limiting the likelihood of escape of, or contamination by, a persistent organic pollutant 9. A POP shall be transported only to a laboratory that has approval to import or manufacture the substance. A

Safety Data Sheet shall accompany each shipment.

10. A POP shall be packaged for transportation in a container within a container (secondary containment) and that

secondary container shall be sufficient to contain any release if the primary container should leak. The

containers shall comply with the Hazardous Substances (Packaging) Regulations 2001 or Regulation 12 of the

Hazardous Substances (Exempt Laboratories) Regulations 2001, as relevant. Outer packages should be

labelled in accordance with the Hazardous Substances (Identification) Regulations 2001.

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11. Transport of POPs by land within New Zealand shall comply with all relevant requirements of the Land

Transport Rule: Dangerous Goods 2005 (Rule 45001).

12. Transport of POPs by sea within New Zealand shall comply with all relevant requirements of either the Maritime

Rules: Part 24A – Carriage of Cargoes – Dangerous Goods (MR024A) or the International Maritime Dangerous

Goods Code.

13. Transport of POPs by air within New Zealand shall comply with all relevant requirements of Part 92 of the Civil

Aviation Rules.

14. Within the laboratory, all POPs shall be stored, handled and labelled in accordance with Regulation 10 of the

Hazardous Substances (Exempt Laboratories) Regulations 2001.

15. A person must not carry any quantity of a POP on a passenger service vehicle.

To exclude organisms from the facility 16. The laboratory manager shall at all times ensure that the laboratory is adequately secured so as to exclude

unwanted organisms, and shall monitor for their presence as appropriate.

To exclude unauthorised people from the facility

17. The laboratory manager shall at all times exclude unauthorised persons from the laboratory in accordance with

Regulation 8 of the Hazardous Substances (Exempt Laboratories) Regulations 2001.

To prevent unintended release of a persistent organic pollutant from the facility 18. The design of the laboratory must comply with Regulations 5 to 8 of the Hazardous Substances (Exempt

Laboratories) Regulations 2001.

19. Procedures must be in place to ensure that no person at the facility is exposed to a level of POP that may cause

harm to that person.

20. At all times a POP shall be prevented from entering any surface water or groundwater system.

To control the effects of any accidental release of a persistent organic pollutant

Breach of containment

21. All laboratories must have an emergency response plan, irrespective of the quantities of hazardous substance

present. The plan must meet the requirements of Part 4 of the Hazardous Substances (Emergency

Management) Regulations 2001. The laboratory manager must ensure that all other relevant requirements of

the Emergency Management Regulations are complied with at all times.

22. If for any reason a breach of containment occurs, the laboratory manager shall notify the Ministry of Business,

Innovation and Employment and the EPA within 24 hours of the breach being detected. It is suggested that if a

breach in containment results in contamination of a waterway, the relevant iwi authorities be advised.

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Disposal

23. The laboratory manager must inform the EPA as soon as there is no longer a requirement to hold any POP for

the approved purposes. The approval holder may at this time—

a. request approval to transfer the substance to another laboratory within New Zealand that, at the time, also

holds approval for the same purposes. The request shall identify the laboratory and the relevant HSNO

approval number, the substance or substances to be transferred, and their amounts; or

b. request approval to transfer the POP to an overseas laboratory in accordance with any relevant

requirements of relevant international conventions to which New Zealand is a party; or

c. arrange for environmentally sound disposal.

Environmentally sound disposal

24. Upon cessation of the requirement to hold any POP for the approved purposes, or upon cessation of this

containment approval, if not transferring the substance in accordance with paragraph 23(a) or 23(b), the

substance must be disposed of in accordance with directions for environmentally sound disposal given by the

EPA by notice in the New Zealand Gazette Issue no 174, 22 December 2004, Hazardous Substances (Storage

and Disposal of Persistent Organic Pollutants) Notice 2004.

25. Environmentally sound disposal also applies to anything that contains a POP following—

a. treatment of any equipment used to contain a POP; or

b. treatment of any spillage of a POP.

Recording, inspection and monitoring requirements 26. A record shall be kept of the quantities of POPs held in the laboratory. The record must be kept for at least 12

months after the substance has been used up or removed from the laboratory.

27. Each time a POP is imported/manufactured, the laboratory shall notify the EPA in writing of the quantities and

nature of the substance(s) concerned.

28. The EPA, or its authorised agent or properly authorised enforcement officers, may inspect the laboratory at any

reasonable time.

Qualifications required of the person responsible for implementing the controls

29. The laboratory must be managed by a laboratory manager with relevant qualifications, skills and knowledge, in

accordance with Regulations 13 and 14 of the Hazardous Substances (Exempt Laboratories) Regulations 2001.

30. All personnel handling any POP must be provided with all relevant information about the POPs they are

handling, as prescribed by Regulation 15 of the Hazardous Substances (Exempt Laboratories) Regulations

2001.

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Appendix 2: Critical review of ball milling for POPs destruction.

Journal of Hazardous Materials 313 (2016) 85–102

Contents lists available at ScienceDirect

Journal of Hazardous Materials

j o ur nal ho me pa ge: www.elsev ier .com/ locate / jhazmat

Review

Mechanochemical destruction of halogenated organic pollutants: Acritical review

Giovanni Cagnettaa, John Robertsonb, Jun Huanga,∗, Kunlun Zhanga, Gang Yua

a State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory of Emerging Organic ContaminantsControl (BKLEOCC), School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR Chinab School of Applied Sciences, AUT University, Auckland 1010, New Zealand

h i g h l i g h t s

• Current knowledge on mechanochemical destruction of halogenated POPs is summarized.• Effective reagents and milling conditions are examined.• Destruction mechanisms are presented in detail.• Future perspectives about research and application are discussed.

a r t i c l e i n f o

Article history:Received 25 November 2015Received in revised form 6 March 2016Accepted 27 March 2016Available online 30 March 2016

Keywords:Halogenated persistent organic pollutants(POPs)MechanochemistryHigh energy millingNon-thermal destruction

a b s t r a c t

Many tons of intentionally produced obsolete halogenated persistent organic pollutants (POPs), are storedworldwide in stockpiles, often in an unsafe manner. These are a serious threat to the environmentand to human health due to their ability to migrate and accumulate in the biosphere. New technolo-gies, alternatives to combustion, are required to destroy these substances, hopefully to their completemineralization.

In the last 20 years mechanochemical destruction has shown potential to achieve pollutant degrada-tion, both of the pure substances and in contaminated soils. This capability has been tested for manyhalogenated pollutants, with various reagents, and under different milling conditions. In the presentpaper, a review of the published work in this field is followed by a critique of the state of the art of POPsmechanochemical destruction and its applicability to full-scale halogenated waste treatment.

© 2016 Elsevier B.V. All rights reserved.

Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 862. Treatment of chlorinated and brominated pollutants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

2.1. Reagents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 882.1.1. Reducing reagents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 882.1.2. Lewis bases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 932.1.3. Neutral species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 932.1.4. Oxidizing agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

2.2. Milling conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 932.3. Reaction mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

2.3.1. Adsorption and activation of reagent surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 942.3.2. Dehalogenation/dehydrohalogenation and the fate of halogen atoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 952.3.3. Carbonization and the fate of organic radicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

∗ Corresponding author.E-mail address: [email protected] (J. Huang).

http://dx.doi.org/10.1016/j.jhazmat.2016.03.0760304-3894/© 2016 Elsevier B.V. All rights reserved.

86 G. Cagnetta et al. / Journal of Hazardous Materials 313 (2016) 85–102

3. Treatment of fluorinated pollutants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 963.1. Reagents for the destruction of perfluorinated compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 973.2. Milling conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 973.3. Reaction mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

4. State of the art and future perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 985. Concluding remarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99

Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

1. Introduction

Mechanochemistry (MC), like many other branches of scientificand technical knowledge, has been utilized unwittingly by mankindfor long time without a specific understanding of its principles.Its earliest application can be dated from prehistoric times whenman used flints to make fire, but only with the first experimentsof Spring and Lea [1] were various MC phenomena systematicallyinvestigated. As a branch of chemistry, it is named according to theenergy source for the reactions activation, in which the chemicaltransformations are initiated or accelerated by the use of mechan-ical forces such as friction, stress, deformation, etc., together withthe high concentration and close contact of the reacting species.Reagents are vibrationally and electronically excited and undergodistinctive physicochemical transformations.

Recent work using atomic force microscopy has shown a sur-prising reversal of bond behavior. It has been found that it takesmore mechanical work to break a low energy bond than it does tocleave the same bond thermally [2]. It is findings such as this thatcontribute to the distinct compounds, phases, and microstructuresthat are come from mechanochemical reactions [3].

Moreover, the main advantage of MC procedures is that theyare generally environmentally friendly. The milling is conductedin a solid phase (without solvents) at modest temperatures andpressures. In some processes the reactions can be carried out usingthe original matrix such as the unmodified contaminated soil orinert materials like quartz sand. Alternatively, co-reagents such asalkali earth oxides and metals can also be used alone or in com-bination. The end products are finely milled inorganic mixtureswith the pollutants often reduced to carbon, carbon dioxide, waterand inorganic halides. All of which are environmentally innocuous.The mills are relatively simple devices that can be constructed ina variety of ways from a range of materials. Because of the modestconditions and absence of hazardous reagents mechanical failuredoes not poses a significant environmental risk and the process canbe turned off and on as needed. The only major operating cost is theenergy to power the mills.

Because of its attractive features, environmental remediationusing mechanochemistry is a new branch of MC. In the last decade ithas become popular because well-known MC methods, using solidreagents, create a chemical environment that destroys pollutants.This new branch draws on the knowledge of inorganic MC whereit has been used for synthesizing metal alloys, catalyst preparationand for understanding the transformation induced in solid reac-tants. Nevertheless, one of the main goals of environmental MC isto destroy organic pollutants, and the new discoveries in the fieldof organic MC are important.

The earliest work on the use of MC to destroy chlorinated envi-ronmental contaminants was 20 years ago by Rowlands et al. [4].Since then, progress has been slow but MC methods are becomingrecognized as a completely viable non-combustion technology todestroy persistent organic pollutants (POPs) that are widely rec-ognized as a threat for human health and the environment [5,6].These compounds are toxic chemicals that originate from man-made sources associated with the production, use, and disposal of

certain organic chemicals. They circulate globally through a pro-cess known as the ‘grasshopper effect’. POPs released in one part ofthe world can be transported to regions far away from the originalsource, through various repeated (and often seasonal) environmen-tal processes. The United Nations Environment Programme (UNEP)established a global treaty, known as the Stockholm Convention,in 2001, to eliminate intentional production and control uninten-tional generation of 12 POPs (the so-called “dirty dozen”); thenother compounds were added to the POPs list (Table 1) [6].

Most of these compounds were formerly produced on an indus-trial scale to be used in agriculture (chlorinated pesticides) andother applications (e.g., PCBs), so huge quantities of these obsoletechemicals (Fig. 1) [7] have accumulated worldwide in stockpilesthat are often poorly managed or have already leaked into theenvironment [8].

According to the Stockholm Convention, the irreversibledestruction of POPs or their transformation into other non-POPmolecules is the preferred action. The destruction of these kindsof pollutants should be complete, achieved by the entire mineral-ization of the compound thus preventing the accidental formationand release of new POP by-products.

Currently, few industrial technologies can be utilized to treatlarge amounts of these types of pollutants. Only high temperaturecombustion technologies are largely available on the market for thedestruction of chlorinated molecules, but the risk of the formationof hazardous by-products such as dioxins still exists [9]. Biodegra-dation technologies are relatively cheap and new bacterial strains,specialized in POP biodegradation, have been discovered [10], butlow bioavailability of these hydrophobic pollutants and their highconcentrations in stockpiles can inhibit bacterial growth. Hencealternative non-conventional destruction technologies are needed.

In order to ascertain if MC technology is truly mature as an alter-native technology for halogenated contaminated waste disposal, asurvey of previously published papers and books on MC treatmentof POPs and halogenated pollutants has been made. Related liter-ature was retrieved by electronic searches on Scopus, ISI Web ofKnowledge, and Google® Scholar. This review is the state-of-the-arton reagents and milling conditions employed to destroy chlori-nated, brominated and fluorinated POPs. Reaction mechanisms arereported for chlorinated and brominated molecules with reducing,neutral and oxidant compounds, while degradation of fluorinatedcompounds deserves a separate discussion; the last part discussesresearch needs and future perspectives for the application of thistechnology on full-scale treatment. In order to avoid unfruitfulrepetitions, pollutant degradation achieved by non-milling surfaceactivation of minerals is not reviewed, since these reactions werealready exhaustively described [11]; similarly, treatments of halo-genated waste (e.g., PVC) are described elsewhere [12]. Of course,some overlaps are inevitable.

2. Treatment of chlorinated and brominated pollutants

A large variety of chlorinated compounds have been inten-tionally or unintentionally (as by-products) produced by mankindthrough industrial processes. The most common are the poly-

G. Cagnetta et al. / Journal of Hazardous Materials 313 (2016) 85–102 87

Table 1Persistent organic pollutants list.

POP Intentional production Use/Origin Carcinogenicity (IARC)b

Aldrin Y Insecticide 3�-hexachlorocyclohexane N By-product of lindane 2B�-hexachlorocyclohexane N By-product of lindane 2BChlordane Y Insecticide 2BChlordecone Y Insecticide 2BDichlorodiphenyltrichloroethane (DDT) Y Insecticide 2BDieldrin Y Insecticide 3Endosulfana Y Insecticide, Acaricide –Endrin Y Insecticide, Rodenticide 3Heptachlor Y Insecticide 2BHexabromobiphenyl Y Flame retardant 2BHexabromocyclododecane (HBCDD) Y Flame retardant –Hexachlorobenzene (HCB) Y/N Fungicide

By-product of chlorinated chemicals2B

Lindane (�-hexachlorocyclohexane) Y Insecticide 2BMirex Y Insecticide 2BOctabromodiphenyl ether Y Flame retardant –Pentabromodiphenyl ether (penta-BDE) Y Flame retardant –Pentachlorobenzene Y Precursor of pesticides

Additive in PCBs products–

Perfluorooctane sulfonate (PFOS) Y Surfactant –Polychlorinated biphenyls (PCB) Y Dielectric, coolant, cutting, and heat transfer

fluid1

Polychlorinated dibenzo-p-dioxins (PCDD) N By-product of some organochlorides, pyrolysisor incineration of chlorine containingsubstances

3c

Polychlorinated dibenzofurans (PCDF) N pyrolysis or incineration of chlorine containingsubstances

3d

Short-chained chlorinated paraffins (SCCP) Y flame retardants, plasticisers, additives inmetal working fluids, in sealants, paints andcoatings, solvent for Dichloramine T(germicide)

2B

Toxaphene Y Insecticide 2B

In bold the 12 compounds of the “dirty dozen”, classified as POPs at the Stockholm Convention in 2001.a Under review [6].b International Agency for Research on Cancer (IARC) classification of carcinogenity: Group 1 “Carcinogenic to humans”, Group 2A “Probably carcinogenic to humans”,

Group 2B “Possibly carcinogenic to humans”, Group 3 “Unclassifiable as to carcinogenicity in humans”, Group 4 “Probably not carcinogenic to humans” [14].c except for 2,3,7,8-tetrachlorodibenzo-para-dioxin, classified in group 1 “Carcinogenic to humans”.d except for 2,3,4,7,8-pentachlorodibenzofuran, classified in group 1 “Carcinogenic to humans”.

chlorinated biphenyls (PCBs), polychlorinated dibenzodioxins anddibenzofurans (PCDD/Fs) (which have similar chemical structureand are commonly called with the general term of “dioxins”),different organochlorine pesticides (OCPs), and hexachloroben-zene (HCB), (Fig. 2 and Table 1). All these molecules are lipophilicand have very low water solubility, so they easily enter the foodchain and accumulate in fatty tissues causing harmful effects onliving organisms [13]. Some of these molecules such as dioxinsare carcinogens, some such as PCBs are pseudo-estrogens and

some such as the pesticides, by definition, have varying degreesof toxicity to different organisms. It is also being recognized thatthese xenobiotic compounds can exhibit both toxicity and carcino-genic/mutagenic properties [14].

Brominated flame retardants are another class of halogenatedmolecules that are recognized to cause adverse effects to ecosys-tems and human health [15]. They are used in consumerproducts, textiles, carpets, paints, electronic equipment, lubricants,chemicals, and fire extinguishers; and are applied to delay

Fig. 1. Obsolete pesticides amounts of stockpiles in the developing world (Source: FAO [7]).


Fig. 2. Some chlorinated and brominated pollutants of major concern today.

incineration and combustion of material, reducing the risk of acci-dental fires. These pollutants are a wide class of biphenyls, alkanes,and cyclic and aromatic compounds with various degrees of bromi-nation; their chemical structure (and, so their physicochemicalproperties) are very similar to chlorinated POPs (Fig. 2). Thesemolecules too are extensively found in the environment and arebelieved to represent a threat for human health due to their ten-dency to accumulate in lipid tissue [13], although evidence ofpotential carcinogenicity exists only for a few of these molecules[14].

Chlorinated and brominated compounds, due to their simi-lar chemical structure and the relative weakness of the aromaticcarbon-halogen bond (C Cl 407 kJ/mol, C Br 346 kJ/mol, comparedto C H 473 kJ/mol [16]) have similar fates during MC treatment.In fact, as reported by all authors that studied brominated pollu-tants (see Table 2 for references), utilized reagents, applied millingparameters and evidence of degradation mechanism are similar tothe ones for chlorinated molecules. Hence brominated and chlori-nated compounds will be discussed together.

2.1. Reagents

In general, regents employed for chlorinated and brominatedPOPs destruction can be divided in three main groups: 1. Reduc-ing agents, which are principally zero valent metals and metalhydrides, 2. Lewis bases such as metal oxides, especially alkali andalkali earth oxides e.g., CaO, 3. Neutral species such as quartz (SiO2)

and alumina (Al2O3), 4. Oxidizing agents such as manganese diox-ide (Table 2).

2.1.1. Reducing reagentsReducing reagents include many compounds, in particular mix-

tures of electron and hydrogen donors. Hydrides are typically usedas electron and H donor at the same time, while zero-valent met-als (e.g., Mg, Fe, Zn, Al etc.) can be utilized alone or with organicmolecules as H donor. This kind of reagent is employed to obtain acomplete dehalogenation in a fast and effective manner as well torecover entirely the dehalogenated pollutant [17], and is useful alsoto treat contaminated materials [18–21]. Actually these reagentsare more efficient dechlorinators than bases such CaO [22,23]. Forexample, the reaction of chlorobenzene and dioxins with CaH2 wasstudied as a mechanically induced combustion, which can be trig-gered by an adequate initial quantity of pollutant in high energymill; the combustion is rapid and gives high dechlorination yields[18,22].

Zero-valent metals are utilized as cheaper (than hydrides)but strong electron-donors. It has been found that their effec-tiveness decreases with reduction potential of the element:Na > Mg > Al > Zn > Fe [21,24,25]. These metals, to accomplish thedehalogenation of pollutants and prevent the formation of uncon-trolled by-products, require the presence of an H donor inthe reaction mixture. Usually alcohols, glycols, and ethers areemployed, but amines and amides were found to be more effective[17,21,26,27].

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Table 2Summary of experimental conditions utilized in reviewed papers that achieved best dehalogenation/degradation results.

Best result conditions

Contaminant Millingdevice

Reagent Reagentratioa

Charge ratiob Rotation speed[rpm] (centrifugalfactor)

Milling time Destructionpercentage [%]

Notes Reference

Chlorinated pollutantsChlorobenzene,

hexachloroben-zene

Vibration mill8000 mixer/mill, SPEX,US

CaH2 Ca:Cl = 2–15 – – 12 h 95 CaO and MgO werealso tested

[22]

3-chlorobiphenyl Planetary ball millPulverisette 7, Fritsch,D

CaO 2.33 (wt) – 700(∼38g)

6 h ∼99 [65]


La2O3 0.05 (wt) ∼14c 700(∼38g)

6 h 100.0 MgO, Mg(OH)2,Al2O3, Al(OH)3,La(OH)3 were alsotested

[28]


CaO + SiO2 0.05 (wt) ∼42c 700(∼38g)

6 h 99.5 [67]

4-chlorobenzene Planetary ball millPulverisette 7, Fritsch,D

CaO 20 (wt) – 700(∼38g)

2 h 100.0 [87]

octachlorodibenzo-p-dioxin,

CaO 200 (wt) – 700(∼38g)

2 h 100.0

octachlorodibenzofuran CaO 200 (wt) – 700(∼38g)

2 h 100.0

DDT Vibration mill8000 mixer/mill, SPEX,US

CaO 7 (wt) 10 – 12 h 100.0 [74]

Dechlorane plus Planetary ball millQM-3SP2, NanjingUniversity Instrument,PRC

Al + SiO2 11 (wt) 30 275(∼ 9g)

2 h 100.0 Fe, Zn were alsotested with SiO2

[25]

Dechlorane plus Planetary ball millQM-3SP2, NanjingUniversity Instrument,PRC

CaO 25 (wt) 36 275(∼9g)

4 h 100.0 [55]

1,3-dichlorobenzene(sand)

Planetary ball millS 1000Retsch, D

Mg 0.046 (wt) 9c 530 rpm(∼22g)

1.33 h 100.0 Reaction mixture:Contaminatedsand, CaO, Ca(OH)2,triethylene glycoldimethylether + Mg,n-butylamine

[26]

Hexachlorobenzene Vibration mill8000 mixer/mill, SPEX,US

CaH2 0.65 (wt) – 875(−)

– 100.0 [64]

Hexachlorobenzene, Vibration mill8000 mixer/mill, SPEX,US

CaH2 1.33 (wt) – 875(−)

– 99.6 In tests with mud, HCBwas used as reactionprimer

[18]

PCDD/Fs (mud) CaH2 5 (wt) – 875(−)

– ∼100

90

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Notes Reference

Hexachlorobenzene1,4-dichlorobenzeneoctachloronaph-thaleneo-nitrochlorobenzene

Planetary ball millAGO-2, Novic Mill, RU

CaONaOH 0.667 (wt) 20 630(40g)

4 min 70–90 Tests were carriedon in comparisonwith the vibrationmill SPEX 8000mixer/mill

[32]

Hexachlorobenzene Planetary ball millQM-3SP2, NanjingUniversity Instrument,PRC

Fe + SiO2 15 (wt) 36 275(∼9g)

8 h 99.9 Fe, CaO, SiO2,CaO + SiO2 werealso tested

[23]

�-hexachlorocyclohexane

Planetary ball millPulverisette 7, Fritsch,D

CaO 60 (mol) ∼98c 700(∼38g)

2 h 100.0 [34]

Mirex Planetary ball millQM-3SP2, NanjingUniversity Instrument,PRC

Fe + SiO2 24 (wt) 36 275(∼9g)

2 h 100.0 CaO, SiO2,CaO + SiO2, Fe werealso tested.

[41]

PCBs (soil) Attritor (ring mill)Pulverisette 9, Fritsch,D

NaBH4 0.05 (wt) 36 750–1000(−)

18 h 100.0 [19]

PCBs (soil), Attritor (ring mill)Pulverisette 9, Fritsch,D

LiAlH4 0.05 (wt) 36 750–1000(−)

3 h 99.9 [20]

Atrazine (soil) LiAlH4 0.05 (wt) 36 750–1000(−)

2 h 100.0

PCBs (sand),dichlorobenzene,pentachlorophe-nol(sand)

Planetary ball millS 1000,Retsch, D

Mg 0.046 (wt) 9c 530(∼22g)

5 h 100.0 Reaction mixture:Contaminatedsand, CaO, Ca(OH)2,triethylene glycoldimethylether + Mg,methanol

[17]

PCBs (sand),dichlorobenzene(sand), pen-tachlorophenol(sand)

Planetary ball millS 1000,Retsch, D

Mg 0.046 (wt) 9c 530(∼22g)

15 min 100.0 Reaction mixturein S1000:Contaminatedsand, CaO, Ca(OH)2,triethylene glycoldimethylether + Mg,methanolReaction mixturein ESM 234:Contaminated PCBsoil + Na,n-propylamine

[21]

Vibration millESM 234, Siebtechnik,D

Na 0.0067 (wt) 9c –(−)

2.5 min 100.0

PCBs(sediment)

Planetary ball millPulverisette 6 Fritsch, D

NaBH4 H:Cl = 14(mol)

10 480(∼16g)

0.5 h ∼98 [57]

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PCBs Stirred ball mill–

Zn + KOH + PEG2000 Glycol:KOH = 1.33Glycol:PCBsoil = 0.6Zn = 1.53 mol/kgoil

– 500(−)

2 h ∼100 Different glycolsand metals werealso tested

[27]

Polychlorinatednaphthalene


CaO ∼57c ∼25c 700(∼38g)

1 h 99.9 [83]

PCDD/Fs Planetary ball millPM 100, Retsch, D

Ca + CaO 100 (wt) ∼4c 400(∼13g)

20 h 100.0 CaO was also tested [37]

PCDD/Fs (fly ash) Planetary ball millXQM-0.4L, Kexi, PRC

CaO Ca:PCDD/F = 1.49�107– 400(∼13g)

2 h 76.8 (PCDD) 56.8(PCDF)

[78]


CaO 0.6 (wt) – 350(∼10g)

2 h ∼60 [54]


Eggshells – ∼60c 400(∼13g)

8 h ∼50 CaCO3 was alsotested

[112]

PCDD/Fs (fly ash)PCBs

Planetary ball millXQM-0.4L, Kexi, PRC

CaO + SiO2 CaO:SiO2:flyash = 4:1:5(wt)

90 275(∼9g)

12 h 84.8 Dioxinsreformation wasobserved duringmilling due tocatalysis of Cucompounds

[117]

Pentachloronitrobenzene Planetary ball millQM-3SP2, NanjingUniversity Instrument,PRC

Nano-Fe 15 (wt) 36 275(∼9g)

4 h 100.0 [76]

Pentachloronitrobenzene Planetary ball millQM-3SP2, NanjingUniversity Instrument,PRC

Fe + Ni + SiO2 24 (wt) 36 275(∼9g)

3 h ∼100 Fe, Fe + SiO2, Fe + Niwere also tested

[82]

Pentachlorophenol Planetary ball millPulverisette 7, Fritsch,D

MnO2 (birnessite) 20 (wt) ∼22c 700(∼38g)

1 h ∼100 [45]

Pentachlorophenol(soil)

MnO2 (birnessite) 40 (wt) ∼7c 700(∼38g)

1 h 75.0

Pentachlorophenol Planetary ball millND7-1L, NanjingNantian TianzunInstrumentCo., PRC

CaO + SiO2 PCP:CaO:SiO2

(mol) = 1:60:6040c 300

(−)5 h – Dechlorination

yield = 58.4%CaO, and CaO + ureawere also tested

[35]

Pentachlorophenol Planetary ball millPulverisette 7, Fritsch,D

MnO2 (birnessite) 20 (wt) 6.6c 700(∼38g)

1 h ∼100 [48]

Pentachlorophenol Planetary ball millXQM-0.4L, Kexi, PRC

CaO + SiO2 Ca:Cl(mol) = 4 ∼9c 400(∼13g)

1 h 98.4 [40]

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Table 2 (Continued)






Notes Reference

1,2,3-trichlorobenzene


CaO 3.71 (wt) ∼35c 700(∼38g)

6 h 99.98 [66]

2,4,6-trichlorophenol

Planetary ball mill–

CaO + SiO2 5.329 (wt) 22.24c 400(−)

6 h 99.0 [79]

Brominated pollutantsDecabromodiphenyl

etherPlanetary ball millPulverisette 7, Fritsch,D

CaO 20 (wt) c ∼23c 700(∼38g)

1 h ∼99 [75]

Decabromodiphenylether


Bi2O3 2.43 (wt) ∼27 700(∼38g)


Hexabromobenzene Planetary ball millPulverisette 7, Fritsch,D

CaO Ca:Br(mol) = 2 ∼35c 700(∼38g)

3 h 100.0 [33]

Hexabromocyclododecane

Planetary ball millQM-3SP2, NanjingUniversity Instrument,PRC

Fe + Quartz 11 (wt) ∼27 275(∼9g)

2 h 100.0 Fe, CaO, Quartzwere also tested.Treatment ofartificiallycontaminatedkaolin andkrasnozem

[89]

TetrabromobisphenolA


Fe + SiO2 11 (wt) 30 275(∼9g)


TetrabromobisphenolA


CaO+ Na2S2O8 Na2S2O8:CaO:TBBPA = 13:52:1(mol)

30 275(∼9g)

2 h 100.0 Fe, CaO, Na2S2O8,

Fe + SiO2,Fe + Na2S2O8 werealso tested.

[50]

Fluorinated pollutantsPerfluorooctane

sulfonate,Planetary ball millPulverisette 7, Fritsch,D

CaO 4 (wt) c ∼20c 700(∼38g)

3 h 99.0 [97]

Perfluorooctanoicacid

CaO 4 (wt) c ∼20c 700(∼38g)

18 h 98.4

Perfluorooctanesulfonate, Perflu-orooctanoicacid


KOH 23 (wt) ∼19c 275(∼9g)

6 h 99.8 CaO, SiO2, Fe + SiO2,NaOH were alsotested

[98]

Chlorinatedpolyfuorinatedether sulfonate(F-53B)


Na2S2O8+NaOH Na2S2O8:NaOH:F-53B = 83:40:1(wt)c

∼10c 275(∼9g)

8 h 88.0 NaOH, Na2S2O8,

Na2S2O8 + FeSO4·7H2Owere also tested.

[99]

a Weight (wt) or molar (mol) ratio expressed as reagent (or total reagents mixture) amount over contaminant amount.b Milling bodies (balls) to reactants mixture (powder) ratio.c Value inferred from data available on the paper.


2.1.2. Lewis basesThe most widely used reagent is calcium oxide, due to its low

cost and availability. Other effective oxides are MgO, Al2O3, La2O3,Bi2O3, while their corresponding solid hydroxides are not useful[22,28–31]; however concentrated KOH solution can be utilized asdehalogenating regent [32]. CaO must be used with large excessto achieve significant dehalogenation rate [33–36], while otheroxides, like Bi2O3, are effective even at stoichiometric ratio withpollutant [30]. It has been found that the addition of metallic cal-cium improves the reactivity of CaO and reduces the amount of CaOrequired [37,38].

2.1.3. Neutral speciesThis group includes all reactants that during milling can easily

generate free radicals or fracture-surfaces with oxidizing centers.SiO2 (quartz) and alumina are the most used compounds of thisgroup. Quartz is a former of surface plasma, which can be used forthe decontamination of all kinds of organic materials from methaneto hazardous organochlorine chemicals by complete mineralization[39]. Addition of quartz to dehalogenating reagent, such as CaO andFe◦, improves their degradation capability [40,41].

2.1.4. Oxidizing agentsManganese oxide can promote the oxidation of organic com-

pounds, and MC processes involving birnessite, (�-MnO2) asynthetic form of manganese dioxide (not to be confused with thenaturally occurring mineral of the same name), has been exten-sively investigated with a wide range of chlorinated pollutants;manual grinding of birnessite often is sufficient to obtain degra-dation products [42–49].

Recently, persulfate (S2O82−), in the form of sodium salt, was

found to be effective to destroy tetrabromobisphenol A, due togeneration of sulfate radicals (SO4

−•) during milling [50].

2.2. Milling conditions

The purpose of an ideal device for a MC treatment is to deliverthe maximum amount of energy into the treated solid and createdefects in the matrix, which greatly affect chemical reactivity [51].Such energy can be extremely localized in the treated solid. With-out this mechanical energy, the fate of reactants and/or the reactionkinetic can be very different. Mechanical action can affect a reactionby improving diffusion, generating strain, structural, electronic andionic defects, as well as by creating pulses of pressure and temper-ature. The effect of mechanical treatment on solid-state reactionscan be both direct, on the chemical stages and diffusion coefficients(which become different in the mechanical stress field), or indi-rect, related to the changes in crystal morphology and generationof defects resulting from plastic deformation and fragmentation[52].

A detailed description of milling devices available on the marketis provided by Baláz [53].

The reaction of a halogenated pollutant with above mentionedreagents occurs only if an adequate amount of energy to breakchemical is provided, otherwise no reaction is observed beforea reasonable time [22]. For the majority of reagents, no reactionhappens with manual grinding or simple mixing [19], so a millingdevice is necessary. Even when reagents show high reactivity per se,like hydrides or zero-valent metals, a high energy mill can remark-ably boost the dehalogenation reaction because of three factors[26]:

1. The continuous production of small sized particles (withdimensions in the range of micro- or even nanometers). This createsa large, fresh supply of highly accessible reagent surfaces.

2. Continuous renewal of surface layers, thereby making sur-face atoms accessible to reactants by removing impurities such as

reaction intermediates, degradation products etc., adsorbed on thereagent’s surface.

3. Activation of accessible surface atoms for reaction by contin-uous impact.

Many variables influence the milling process, such as the typeof mill, milling matrix, ball-to-powder ratio, filling extent of themilling chamber, milling atmosphere, milling speed, milling timeetc. [53]. The charge ratio (i.e., ball-to-powder ratio) and therotation speed are considered fundamental parameters in dehalo-genation reactions. These control the specific energy density withinthe matrix [25,32,40,54,55]. In fact, dehalogenation kinetic con-stants are generally proportional to charge ratio and rotation speed[41]. However, recently it was confirmed that the charge ratiois insufficient to describe entirely a MC process; vial volume, itsfilling ratio, diameter and quantity of milling balls, and powdermass are important as well as the above mentioned two param-eters [56]. Such inadequacy is not surprising, since the charge ratiocompletely neglects the dynamical features of the milling process.Thus, all parameters need to be considered for dehalogenation reac-tions and, because of the complexity, an iterative optimization of aparticular mill and process needs to be done to get the best dehalo-genation/degradation yield [35,57].

Essential information on the most effective operating parame-ters of the chlorinated and brominated compounds MC treatmentdescribed in the reviewed papers is reported in Table 2. The firstproblem is the long time milling generally required to achieve thecomplete degradation of the pollutants. This is a key point becauseenergy consumption is the major weakness of MC technology. Ingeneral, high charge ratios and rotational speeds reduce millingtimes but require more powerful and energy costly mills. The mostcommonly used mills are planetary ball mills, then some vibrationalmills and a few attritor mills. This is partly due to the availability oflaboratory mills and the limited amount of large scale mill develop-ment. Consequently, an aspect that has not been adequately studiedyet is the influence of different actions type (i.e., compression andshear) of milling devices. In fact, a continuous hydrostatic com-pression results in physical and chemical processes that are verydifferent from those induced by compression combined with shear.The ratio of impact/shear during treatment can vary over a widerange, depending on the type of device used, and this also plays acrucial role in the outcome of processes that occur [58,59].

2.3. Reaction mechanism

Generally speaking, two types of bonds-rupture processes occurunder the action of mechanical stress. The first type involves disor-dering and amorphization of crystal structure and conformationaltransformations as a result of the rupture of intermolecular bonds.The second type includes MC reactions activated by deformation ofvalence bonds and angles under mechanical stress, namely, the rup-ture of bonds, bond reformation and, depending on the atmosphereand matrix, oxidation, hydrolysis and other chemical reactions [60].

The destruction of chlorinated and brominated pollutantsbelongs to the second type of process. The first step of themechanism is the adsorption of the molecules on the sur-face of the solid reagent; this step is facilitated by milling.Then the activated surfaces of the reagent react with the pol-lutant by some pathway such as electron transfer to radical,ions or organometallic intermediate; oxidation. After prolongedgrinding of the solid mixture, if the milling process is ener-getic enough, organic compounds are reduced to a mixtureof amorphous and graphitic carbon and light hydrocarbons.Halogens form inorganic halides. In a practical milling sit-uation, various amounts of carbon dioxide are also formed(Fig. 3).


Fig. 3. Scheme of general degradation process for chlorinated and brominated pol-lutants.

2.3.1. Adsorption and activation of reagent surfaceGrinding has the primary effect of mixing reagents and ensur-

ing an intimate contact of the solids. In the case of solid–solidreactions, the total contact area and the structure of a multicompo-nent mixture determine the reaction course [52]. Hence significantacceleration of the reactions can be achieved in high energy mills,because the elevated pressure increases the contact area amongreacting particles and promotes the diffusion across the interface[61]. This is crucial in environmental applications, where pollutantsin contaminated waste are often adsorbed on a solid matrix or intofine particles in the matrix, and a close contact with reacting solidsis necessary to ensure destruction.

Nevertheless the most important effect of high energy milling isthe surface activation of solids. When mechanical forces are appliedto solids, the strain field manifests itself specifically by the shifts ofatoms from the equilibrium positions at lattice nodes, the changesof bond lengths and angles, and, in some cases, the excitation ofelectron subsystem. These states are metastable and are followedby relaxation via four different channels: accumulation of defects,amorphization, formation of metastable polymorphous forms, andchemical reactions; these channels are jointly called “mechanicalactivation” of solids [61,62].

It is difficult to ascertain whether mechanical activation hasoccurred. In fact, in the majority of reviewed papers it is assumed

that some kind of activation happened during milling, since thepollutants being investigated were destroyed and the expected endproducts were found.

2.3.1.1. Lewis bases and reducing agents. Clues to the relation-ship between reducing agents activation and dehalogenation werefound. First of all, sole mixing of a highly reactive compounds, likeCaH2, is not sufficient to perform the dehalogenation reaction [22].Moreover, during milling the reaction with hydrides does not hap-pen if the impact energy of a single hit is not high enough to activatesolids, i.e., more than 0.07 J/hit [22,63]. Lag time from the beginningof grinding and the detection of first reaction products is observed[17,22,24,26,64]. This lag period is required to allow comminu-tion of reagents, which increases their intimate contact and theaccumulation of structural defects in solids, and makes the chem-ical reactions occur [22,24,64]. The most important clue of solidsactivation is the presence of reactive sites on CaO (as well as MgOand other oxides of the second and the third group) where the oxideion is activated by grinding and is induced to transfer charge tothe adsorbed halogenated pollutant. In addition, surface trappedelectrons generated by grinding were detected [28,65–67]. No acti-vation was found for corresponding hydroxides because no chargeseparation occurred [28,65].

Finally it is worthy of mention as a proof of zero-valent metalssurface activation the two works of Birke et al. [26,68], which intheir kinetic analysis of tri-, di- and mono-chlorobenzene dechlo-rination with metallic magnesium introduced a “surface function”.This sigmoidal shaped function reflects a hypothesized growth ratefor reactive surface sites (activated magnesium atoms), which is invery good agreement with experimental results.

2.3.1.2. Neutral and oxidizing agents. Among reagents employedfor degradation of halogenated pollutants, quartz and birnessiteare known to be activated under mechanical action. Grinding caninduce the cleavage of crystals, thus producing fresh surfaces. Theseare highly-reactive due to the bond breakage, and the consequentexposure of free radicals may initiate chemical reactions. Althoughmixing is not enough to induce birnessite activation [48], this oxideis very reactive and can be activated by simple manual grinding[47]. The activation of ground SiO2 and the consequent radicalformation on its surface has been well-known since 1960s [69],and has been successfully applied to pollutant degradation [39].In particular, grinding of quartz produces silyl (E’ centers, Si•) andsiloxyl radicals (nonbridging oxygen hole centers, SiO•) on its sur-face because of the homolytic cleavage of Si O bonds. Two kind ofactivated sites are generated in this way: sites formed by fracture ofparticles and sites created by attrition between them with no sig-nificant increase of specific surface area. Active sites generated byfracture exhibit a significantly higher reactivity than the ones gen-erated by attrition [70]. Hence the choice of a suitable milling deviceand the proper particle size of quartz, employed as additive in thereaction mixture for pollutant treatment, can boost remarkably thedegradation process [23].

Persulfate is known to generate the sulfate radical (SO4−•) in

aqueous solution by thermal (T > 300 ◦C) and sonochemical (ultra-sound) induction via a homolytic cleavage of the peroxide bridgebetween the two S atoms [71]. This radical anion has a very highreduction potential (E◦ = 2.6 V), similar to hydroxyl radical (OH•E◦ = 2.8 V) [71], so has a strong oxidant behavior. The well-knownanalogy between MC and sonochemistry (which is, actually, recog-nized as a branch of the former [72]) allow us to hypothesize thatthe same reaction happens in MC reactors at solid state.

It is worth noting at this stage that most discussions of inorganicions, radicals and their redox potentials, indeed even their abilityto perform as redox systems, has been mostly studied in solutions,generally aqueous solutions. To a limited extent there have been


gas phase studies but whether this can be strictly carried over intototally anhydrous reactions on the surfaces of solids is debatable.

2.3.2. Dehalogenation/dehydrohalogenation and the fate ofhalogen atoms

Dadali et al. [73] demonstrated that mechanically activatedsolid-state reactions between two reactants, one of which is anelectron donor, while another is an electron acceptor, generate freeradicals. Accordingly, the activation of the dehalogenating reagent,which is already in close contact with the organic pollutant dueto grinding, permits the electron exchange with pollutant, causingthe breaking of carbon-halogen bond and the formation of ions andradicals.

2.3.2.1. Lewis bases and reducing agents. As mentioned above oneof the most utilized agents is calcium oxide, so its reaction withhalogenated compounds has been deeply studied. This compoundcan be considered a model for all oxides employed as dehalogenat-ing reagents.

After the cleavage of CaO crystals and the exposure of newsurfaces, the oxide ions are induced by mechanical activation totransfer an electron to pollutant’s carbon atoms, thus generatingan anion radical (Fig. 4). The electronegativity of halogens and theweakness of the C X bond promote the expulsion of the halide,leaving an oxide radical and a pollutant free radical. However thisreaction step is not clearly defined; sometimes intermediate com-pounds with a higher degree of halogenation are found, suggestingthat a halogen radical, instead of halide, is generated. Then the halo-gen radical may encounter another pollutant molecule and causeits halogenation by substitution of one hydrogen atom via radicalmechanism [66,74]; or, more commonly, the halogen radical maybe trapped into the CaO lattice, where it is transformed into halideby the addition of another electron.

Halogenated intermediates, produced by the dehalogena-tion of the pollutant, are commonly found in the matrix[22,26,34,40,66,74–77]. Kinetic analysis of the formation of inter-mediates does not seem to follow a particular order, for examplefrom the most halogenated congener to the non-halogenated one,but seems to be a somewhat random process [78].

The halides generated by dehalogenation are bound to Ca2+ cen-ters, giving origin to two salts: Ca(OH)X [18,28,40,66,78–80] andCaX2 that tends to absorb water from environment to becomeCaX2 × nH2O [22,33,40,55,66,75]. Wadalite, a chlorinated mineralphase, was also found by XRD after ball milling of PCDD/F con-taminated fly ash with CaO [78]. It is noteworthy that inorganichalides are usually extracted from ground samples by hot waterfor quantification after milling. However sometimes stoichiomet-ric recovery of halides is not possible, because they may remainwithin the final product matrix, or may be still bound to carbonatoms, or trapped between solid products layers [41,76].

The pollutant free radical, generated by dehalogenation, can fur-ther react with an oxide ion or an oxide radical to form a strongC O bond (Fig. 4). Ikoma et al. [65] found two strong peaks cor-responding to radical generation in the ESR spectrum of CaO andmonochlorobiphenyl mixture ground for 6 h. They assign a sharppeak to the electrons trapped in oxygen vacancies on the surfacesof the oxide and the other broad one to oxygen-centered aromaticradicals coming from chlorobiphenyl. Tanaka et al. [66] confirmthat organic carbon is bound to inorganic oxygen by FTIR analysisof 1 h ground sample of trichlorobenzene, while the same authors[28] showed the existence of the carbon oxygen bond for MgO.

The dehalogenation reactions do not require the presence of Hatoms in the molecule or H-donor species, in fact per-halogenatedpollutants are successfully treated [18,22,23,30,32,33,76,81–83].

On the other hand, pollutants with halogenated non-aromaticmoieties can be dehalogenated (by ball milling with CaO) only if

hydrogen atoms are present in the molecule. In particular, thisdehydrohalogenation pathway has been observed, until now, onlywith chlorinated species, when hydrogen and chlorine atoms canadopt an antiperiplanar position. One proton and one chloride areexpelled through aliphatic elimination mechanism (Fig. 5); then thehydrogen electron pair form a double bond, so alkenes and aromatic(chlorinated) intermediates are generated [34,74,84]. Aromaticintermediates then follow the above-described dehalogenationpathway. These reactions need to be carefully compared to simplethermal degradation which also requires the antiperiplanar confor-mation. A good example is DDT which rapidly dehydrohalogenatesin the first stages of milling to form DDE. However DDE can be seento form spontaneously, even at room temperature [85].

The reaction mechanism of zero-valent metals (anothertype of reducing reagents) may pass through the forma-tion of organometallic intermediates, which readily reacts withH-donor compounds due to their strong basicity. Birke et al. [26,68]suggest a Grignard-like reaction of tri- and dichlorobenzene withmetallic magnesium, producing chlorophenylmagnesium chloride.This reaction can be assimilated to the model showed in Fig. 4 forCaO, but, at the last step, the organomagnesium halide is formed(Fig. 6).

The dehalogenation mechanism with hydrides (CaH2, NaBH4,LiAlH4), which act as reducing reagents and together as hydrogendonors, is the nucleophilic substitution of H− ion with halogen atom[19,20]. This kind of reaction is mechanically induced and, after acertain lag time, proceeds as combustion [18,22].

The nucleophilic substitution of chlorine atoms with hydroxideion was also obtained by Korolev et al. [32] during ball milling ofoctachloronaphthalene and hexacholorobenzene with potassiumhydroxide. Reaction is carried out under hydrothermal conditions,utilizing a 40% aqueous solution of KOH. The authors report thatreaction with solid KOH also occurs when the conditions corre-sponding to hydrothermal mode are created in the MC reactor.

2.3.2.2. Neutral and oxidizing reagents. Dehalogenation of pollu-tants can be obtained as collateral effect of the reaction withoxidant like �-MnO2 (birnessite) and SO4

−•. Birnessite is reducedto Mn3+ and Mn2+ during mechanical treatment, while organic pol-lutants are oxidized to form radicals and cations. Incidentally thesefragments can dehalogenate other molecules via radical/cationsubstitution and consequent halide expulsion [47,48]. Moreoverthese reactions seem to be more probable with low halogenatedcompounds [44]. Active surface of SiO2 (described in paragraph2.3.1.2) can bound directly halogen atoms from pollutant moleculeby radical reaction. For example, quartz E’ centers ( Si•) and non-bridging oxygen hole centers ( Si O•) react with C Cl bond to giveorigin to carbon and two other species, i.e., Si Cl and Si O Cl,which are hydrolyzed in aqueous solution [23].

To the best of our knowledge, persulfate has been utilized onlywith brominated POPs. The detachment of bromine from the pol-lutant molecule may follow a radical pathway too [50].

2.3.3. Carbonization and the fate of organic radicalsThe pollutant carbon skeleton, after having undergone (par-

tial or total) dehalogenation to form radicals, may pass throughdifferent kind of reactions: dehydrogenation, hydrogenation,oligomerization, fragmentation and finally graphitization tobecome a mixture of amorphous and graphitic carbon (Fig. 3). Thesereactions have in common the existence of organic radicals afterdehalogenation of the pollutant molecule. The presence of inter-mediates with electron-deficient carbons is corroborated by phenylgroup migration from C1 to C2 in DDT molecule during ball millingwith CaO [74]. Furthermore, as already noted in 2.3.2.1, ESR analy-sis confirmed the presence of radicals [33] and, in particular, the


Fig. 4. Dehalogenation mechanism with CaO.

generation of oxygen-centered aromatic radicals during ballmilling of chlorinated biphenyl with CaO [28,66].

The dehydrogenation reaction is observed in high energy milledpollutant, where dehydrogenated intermediates/by-products(alkenes and aromatic compounds) are produced [32,66,74,86,87].It is likely, but not confirmed by experimental results, that thedehydrogenation mechanism is similar to the dehalogenation one,shown in Fig. 4, where X = H, but with expulsion of a hydrogenradical. If such hypothesis is correct, during grinding both reactionswould happen simultaneously, but dehalogenation rate wouldbe faster because of the weakness of the carbon halogen bond(C Cl 407 kJ/mol, C Br 346 kJ/mol, compared to C H 473 kJ/mol[16]). This process probably generates the major part of hydrogenradicals that exist in the reaction mixture, but a minor part comesfrom traces of water in the reaction [83,86,87]. In the dehydro-halogenation mechanism (Fig. 5), the loss of hydrogen does notproduce H• radicals.

The H• radicals generated during milling react with otherorganic species, or their fragments, to form reduced compounds.Hydrogenated products, apart from partially or totally dehalo-genated compounds, can be (cyclo) alkanes [83,86,87] or volatilecompounds like, CH4 and C2H6 [22,34,66]. About the hydrogena-tion, two interesting cases deserve more discussion. The first is thegrinding of octachloronaphthalene with dry CaO (heated for 2 hat 800 ◦C): although no hydrogen atoms were present in reagents,hydrogenation products were observed, probably due to envi-ronmental humidity in the grinding jar [83]. The second case isfortuitous hydrogenation by solvent during extraction procedure;it was demonstrated that nitro group of pentachloronitrobenzenewas activated by ball milling, but it was hydrogenated to amineby the acetone, utilized as the extracting solvent [76]. A specialreference is due for intentional hydrogenation by the addition ofstrong reducing reagents like hydrides (which has been already dis-cussed in section 2.3.2.1) and H-donors to the reactions. Alcohols,ethers, and in particular amines and amides, added to zero-valentmetals, improve the hydrodehalogenation of pollutants followinga Grignard-like reaction. The pollutant molecule reacts with metal,forming an organometallic compound, which is a very strong baseand readily undergoes protonation, like the above mentioned H-donors [17,21,26,27,68]. As noted above however, some cautionneeds to be made in assuming that these solid surface reactionsbehave like solution chemistry.

Oligomerization is a typical reaction for radical species, whichfollows addition mechanism. Polymers formed by few units of(partially or totally) dehalogenated pollutant have been identifiedduring grinding with different reagents [22,32,47,64,83,87].

When milling energy is not only enough to break C X bond,but can also cause the rupture of C C and C C bonds of the pol-lutant carbon skeleton, then the fragmentation occurs with theproduction of gaseous products, principally CO2 and CH4 with someCO and, depending on the molecules present, minor amounts ofsmall saturated and unsaturated hydrocarbons [22,30,34,64,83,87].Milling pollutants with a dehalogenating reagent in argonatmosphere also produces methane and hydrocarbons but verylittle or no CO2 or CO indicating that volatile hydrocarbons aredirectly produced by MC treatment and not by accidental reactionswith unintentionally inserted reactive species (e.g., aerial oxygen)[30,66]. If CaO is used as dehalogenating reagent, often CaCO3 isfound in milled solids as a consequence of the carbonation of theoxide by the CO2 generated from pollutant degradation [40,66,79].Nonetheless CaCO3 also has a dehalogenating effect [40,88].

The extensive dehalogenation/dehydrogenation and the conse-quent polymerization cause the carbonization of the pollutant. Ithas been shown that, after long time high energy milling, groundsamples become darker because of carbon formation as final prod-uct [22,23,25,28,30,36,40,41,55,64,66,74,76,77,79,80,82,87,89]. Itis worth commenting that if metal jars or balls are used withabrasive matrices such as quartz, the samples darken due tofinely divided metal which could be mistaken for carbon forma-tion. Raman spectra of milled material are slightly variable anddepend on the matrix, but, in general, a disordered peak between1350 and 1360 and another peak at 1580 cm−1 are seen. Thesepeaks suggest mixtures of graphite and amorphous carbon in vari-able ratios. The spectrum for single graphite crystals show a lineat 1575 cm−1, while other amorphous graphite materials, suchas stress-annealed pyrolytic graphite, commercial graphite, acti-vated charcoal, lampblack, and vitreous carbon, display a band at1355 cm−1 [23,76,90–92].

Inorganic carbon is generally the final degradation product oforganic compounds that undergo intensive high energy milling[93,94]. The carbonization mechanism probably passes through theformation of high molecular weight organic compounds generatedfrom an accretion process determined by addition of organic radi-cal fragments to form the ultimately most stable carbon products[40,95]. Hence addition to the reaction mixture of a good radi-cal generator such as SiO2, accelerates the carbonization process[40,77].

3. Treatment of fluorinated pollutants

Perfluorinated compounds and related derivatives are a group ofindustrial compounds that have been extensively utilized as flame

Fig. 5. Dehydrohalogenation mechanism.


Fig. 6. Dehalogenation mechanism with metallic Mg, forming Grignard-like intermediate.

Fig. 7. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) molec-ular structure.

retardants, surfactants, lubricants in many industrial and consumerproducts. Because of the high energy of the C F bond (533 kJ/mol[16]) and of the perfluorination of the carbon chain, these moleculesare chemically stable, insoluble in polar and nonpolar solvents, andresistant to oxidation, reduction, and biodegradation [96]. In par-ticular two compounds were added to the POPs list in 2009 review[6]: perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid(PFOA) (Fig. 7). Due to their polar acid groups these molecules arequite soluble in water and are now ubiquitous in the world’s aquaticenvironments [13]. In common with other POPs, these pollutantsare remarkably stable in the environment, and accumulate in lipidtissues of animals, posing a risk to human health.

Information on MC degradation and destruction of these newPOPs is poor because only in recent times this class of compoundshas attracted the due concern (Table 2).

3.1. Reagents for the destruction of perfluorinated compounds

Calcium oxide is also effective for destroying perfluorinatedcompounds, in particular PFOS and PFOA, as verified by Shintaniet al. [97]. In our laboratory (SKJLESPC), we tested CaO and otherreagents (SiO2, Fe0 + SiO2, and NaOH) obtaining poor degradationyields as well low fluoride recovery, while complete destructionwas achieved by KOH [98]. The different results obtained with CaOby the two research groups confirm the relevance of milling condi-tions adopted for the treatment. This will be discussed in the nextparagraph.

Lately, it was demonstrated that persulfate coupled with NaOHis effective to degrade perfluorinated compounds [99]

The very good performance of KOH compared to the poor oneof NaOH is an interesting issue that requires further investigations.The humidity adsorbed from the air into the jars may play a centralrole to inhibit the MC reaction. In fact, it is known that the presenceof solvent dramatically reduces the efficiency of ball impacts, i.e.,the energy transferred from milling bodies to powder, and onlyunder specific conditions can be useful to carry on the reactions[100,101].

3.2. Milling conditions

To describe the mechanochemical activation of a solid, twoparameters play a key role: The milling intensity, which is therate of energy transfer to the milled powders, and the energy dose,which is the total amount of mechanical energy transferred to pow-der, usually utilized as a specific quantity per unit of powder mass,namely the specific dose [102]. The specific dose provides a usefuldescription of the milling progress for different devices and milling

conditions. In fact, the energy dose required to obtain a certaindegree of structural transformations is a characteristic, invariantquantity of the system that undergoes high energy milling. In otherwords, the transformation degree depends only on the total amountof energy supplied to the material and not on the energy intensity ofthe treatment; typically milling intensities range from microwattsto tens watts per gram (W/g). This finding was demonstrated forinorganic systems [103–107] and also for the dehalogenation ofchloro-organics [63,108]. Moreover, the specific dose is compara-ble when milling devices with different type of action are used toachieve the same degree of material refinement [109].

In the MC treatment of PFOS with CaO described in reference[97] and [98], and summarized in Table 2 (in Ref. [98] the sameconditions used for KOH are utilized with CaO, except for the millingtime, which is 4 h). Simple calculations (based on Ref. [108]) showthat the specific energy dose introduced in the reaction mixtureduring milling by Shintani et al. [97] is equal to 131 kJ/g, near 8 timesthe energy used in our laboratories [98], which was only 17 kJ/g.This difference may explain why almost no degradation with CaOwas achieved by us.

The same energy balance can be made about milling conditionswith KOH as reagent: The specific dose required to obtain the same“degree of refinement” of the reaction mixture, i.e., the near com-plete destruction of PFOS, is much lower than when using CaO. Thatis to say, KOH is more energy efficient than CaO (of course, dif-ference in reagents cost and availability should be also taken intoaccount when assessing economic feasibility of the treatment).

However, only two examples of MC treatment are not enough tothoroughly understand the influence of milling parameters on thedegradation of PFOS and, in general, on perfluorinated compounds.

3.3. Reaction mechanism

The general considerations written in paragraph 2.3 for chlori-nated and brominated pollutants are obviously valid for fluorinatedcompounds too. Namely, the mixing and the consequent close con-tact among reagents, as well the MC activation of the solids, makethe reaction happen in solid phase.

The activation of CaO should follow the same mechanism ofcharge transfer ascertained by various authors in experiments withchlorinated pollutants [65,80] (and described in detail in section2.3). The same authors verified that hydroxides are ineffective todechlorinate POPs because no electron transfer occurs.

On the other hand, fluorinated organic compounds are alsodegraded by potassium hydroxide. This finding is the most inter-esting difference between fluorinated and chlorinated/brominatedcompounds because the latter seem to be more susceptible to redoxreactions, while the former is much easily degraded in non-redoxconditions.

A MC degradation mechanism for perfluorinated compounds co-milled with KOH is proposed in Fig. 8, based on the work of KunlunZhang in our laboratory [98,110]. During milling, KOH first attacksthe most labile moiety of the fluorinated molecule, which is usuallya substituent group with many electronegative atoms (e.g., sul-fonate or carboxyl group) that can easily react with a nucleophilic


Fig. 8. MC degradation mechanism of perfluorinated pollutants co-milled with KOH.

reagent (i.e., OH−). Consequently, the separation of the mentionedgroup and its mineralization (to sulfate or carbonate) occurs.Then fluorine atoms are substituted by hydroxides due to theirnucleophilicity, and a third hydroxide ion induces the subsequentcleavage of the bihydroxylated carbon from the mother-chain,which generates formate (potassium salt) and water (by conden-sation of two hydroxyl groups that form a carboxyl [111]). This“flake-off” process repeats itself until the complete destruction ofthe carbon chain. Nevertheless, a different fragmentation pathwaywas reported for another perfluorinated compound [110], whereperfluoropropyl fragments were split from the “mother-chain” bymechanical action. Afterward both pieces are degraded through theflake-off mechanism.

It is noteworthy that the described mechanism does not end incarbon as the final product, like in redox reactions with chlorinatedand brominated compounds. Indeed the oxidation state of carbonatoms remains unchanged in reagents and products (i.e., formate),that is +2, as expected from a nucleophilic substitution reaction.

4. State of the art and future perspectives

During the last two decades the MC technology has been studiedas an alternative, non-combustion technology for POPs destruc-tion. The first steps have been taken toward a full scale applicationof POPs MC treatment. (1) There is a general understanding ofthe reaction mechanisms. (2) Different reactants have been shownto be effective in achieving sometimes a complete by-productfree destruction of POPs, even with extremely stable compoundslike PCBs, obtaining in some cases the complete mineralization to

carbon and halides, and in other cases the complete dehalogena-tion and the recovery of the dehalogenated pollutant. (3) The mainmilling parameters have been identified, and their influence on thefinal degradation/dehalogenation yield investigated.

However, these steps are not enough to let us consider the MCtreatment a mature technology that can be employed for POPswaste material reclamation in safe and economically viable man-ner. At the moment, all milling and reaction conditions of the MCdestruction of POPs are rather harsh, e.g., high reagent to pollu-tant ratios, intense energy milling for quite long times (severalhours), etc., which are difficult to transfer on full scale and arenot economically feasible. The selection of proper milling devicesand convenient reagents mixture to improve reaction kinetic wouldpermit to reduce energy costs, in terms of power requirement andmilling duration.

The choice of the most suitable milling device to destroy halo-genated pollutants has been hardly ever investigated, because untilnow the most utilized equipment is laboratory scale planetary ballmill. However, in MC it is well-known that different combinationof impact and shear may produce different effects on inorganic andorganic materials. An example can demonstrate the importance andthe diverse influence of milling devices. Birke et al. [17] suggest that,utilizing a planetary ball mill, metallic magnesium (with methanoland triglyme) is more effective than zinc to dechlorinate PCBs; oncontrary, Nah et al. [27] find that, employing an attritor mill, zincis better than magnesium to dechlorinate the same contaminants.

Selection of apposite reagents is another research issue thatcan produce further development. There are many examplesthat demonstrate a remarkable boost of the dehalogenationreactions when common reagents (e.g., CaO) are coupled withother reducing/oxidizing reagents [23,25,37,41,82,89]. However,the interactions among reagents and the synergistic effects of mix-tures have been seldom investigated. Other interesting results havebeen already obtained with unusual reagents. Eggshell waste ismore effective than CaCO3 as co-grinding reagent to reduce dioxinsin fly ash [112]. Aluminum and quartz mixtures can be reuti-lized to treat dechlorane plus (a polychlorinated flame retardant),and the destruction yield, under best milling conditions, decreasesfrom 99% to 94–95% only after the third utilization [25]. In previ-ous works, we demonstrated that special reagents can be used toproduce, together with POP dehalogenation, special-purpose mate-rials, like catalysts for other (environmental) applications [30,82].

In addition to development of milling devices and new reagents,the insight into reaction mechanism with various reagents andunder different conditions is fundamental for full scale applica-tion, because it allows a fine tuning of the process. Currently, themain issue is the unsatisfactory level of the understanding aboutpollutant interactions with solid reagents. In particular: 1. Thedehalogenation mechanism with CaO (and other oxides) has beeninvestigated at length but some aspects of the reaction, such as thehalogen radical formation and dehydrohalogenation mechanismsare still not clear. 2. For oxidizing reagents, only some hypothesizedmechanisms have been proposed. 3. The kinetics of the dehalo-genation and destruction reactions have not been satisfactorilydetermined [26,68,108]. There is also a very poor knowledge offluorinated pollutants, whose chemistry can be quite peculiar dueto the high stability of the carbon fluorine bond, as demonstratedby two pioneer works (reported in Section 3).

MC is a good candidate technology to treat every kind ofsolid waste, from pure POPs stockpiled around the world to haz-ardous waste, like contaminated soil, sediment, fly ash, industrialsludge, etc. Actually, stockpiles of old pesticides and other man-made halogenated compounds are often poorly stored, especiallyin developing countries, and toxic chemicals leak into the envi-ronment, turning potentially fertile soil into hazardous waste.Hence the remediation of contaminated soils near storage sites


Table 3Essential characteristics of existing pilot/full-scale mechanochemical technologies.

Company Technology Milling device type Throughput Maximum feed Energy requirement

EnvironmentalDecontamination Ltd., NewZealandwww.edl-asia.com

Mechano-ChemicalDestruction,MCDTM

Stirred ball mill Continuous 15 t/h 75 kWh/t

Radical Planet ResearchInstitute Co. Ltd., Japanwww.radicalplanet.co.jp

Radical planettechnology

Planetary ball mill Batch 200 kg 540 kW

Tribochem.de, Germanywww.tribochem.de

Dehalogenation byMechanoChemicalReaction (DMCR)

Vibrational mill Batch/Continuous 1 t/h 160 kWa

a Retrived from Siebtechnick GmbH web-site, www.siebtechnik-gmbh.de.

is usually required. From the economic point of view, a versatiletechnology, like MC, capable to accomplish the treatment of differ-ent solid contaminated materials is preferable.

Nevertheless further research on complex solid waste matricesis also necessary. Solid–solid interaction plays a fundamental rolein MC. This is particularly true for environmental MC, where con-taminants have complex interactions with organic and inorganicfractions of solid waste. Clay minerals and metal oxides are com-ponents that typically constitute the inorganic fraction of differentkind of waste, in particular of contaminated soils and sediments.These components can promote a number of reactions associatedwith the environmental impact of organic pollutants. As reviewedby Nasser and Mingelgrin [11], through the activation of these com-ponents, MC treatment can induce the degradation of a numberof pollutants, included POPs. Besides, the addition of reagents tothe contaminated material can boost MC destruction in contami-nated material [20,54,89,113–116]. On the other hand, undesirableeffects produced by inorganic components were also observed.Recently, it was reported that the presence of catalysts for dioxinreformation (e.g., copper chlorides and oxides) in secondary coppersmelting fly ash can induce, PCDD/Fs and dioxin-like PCBs regen-eration via de novo synthesis under milling conditions [117]. Theinfluence of the organic matter on degradation mechanism hasbeen only partly investigated, and the role of the organic matterduring milling of organic pollutant is still undetermined. Pizzigalloet al. [43] report an improvement of pentachlorophenol degrada-tion with manual ground birnessite due to the presence of humicacids in the reaction mixture. Per contra, inhibitory effect of organicmatter, which would act as radical scavenger, on MC degradationof hydrocarbons was also described [118].

All mentioned aspects require further studies to make thistechnology a convincing, economically feasible alternative to com-bustion technology for POP waste disposal.

Finally, despite the various uncertainties regarding the MCdestruction of halogenated pollutants, in particular when theyare present in solid waste, three pioneer MC technologies havebeen developed and applied on pilot- and full-scale treatmentof POPs: “Radical planet technology” [119,120], “Mechano-chemical destruction” (MCDTM) [119,121], and “Dehalogenation bymechanochemical reaction” (DMCR) [122]. Their main features aresummarized in Table 3.

According to information available on websites, only the MCDTM

is currently (Winter 2016) involved in decontamination projects.Indeed, comparing energy requirements and treatment capacityof the three technologies, it is evident that energy consumptionis their weak point. MCDTM, which has the best energetic per-formance, is designed for contaminated soils and similar waste.Its advantage is that it is a continuous process that can remedi-ate contaminated materials of up to 5% pollutant content withoutany pre-treatment other than drying to reduce steam genera-tion. Nonetheless the energy consumption per mass unit of pure

pollutant of MCDTM is comparable with the two other technolo-gies. Energy costs can make MC seem uncompetitive with someother technologies but the simplicity of the process and the abilityto easily scale the process makes it an attractive alternative. Obvi-ously a lot more work needs to be done to better understand themechanisms and optimize the technology.

5. Concluding remarks

A review of papers concerning the MC dehalogenation anddestruction of POPs was carried out. Milling matrices, reagents,milling conditions, and the current knowledge about reactionmechanisms were evaluated for chlorinated, brominated, and flu-orinated pollutants to ascertain whether milling is an alternativetechnology to thermal treatment for contaminated soils and POPstockpiles.

Many reagents, in reducing and oxidant conditions, have beentested with satisfying results. Almost all comply with the basicrequirement of not generating any toxic products. Among reagents,CaO is the most important one, because it can dehalogenate anddestroy (if milling is energetic enough) all POPs that have beeninvestigated. CaO is also a cheap and largely available material.However more effective agents with very interesting secondaryeffects (dehalogenation boost, catalysts production, waste bene-ficial reuse) have also been already successfully tested.

Even for the MC POPs destruction, high energy mills are akey factor of the treatment. They allow the reaction betweenPOPs and the substantially inert material usually used as reagentsby providing the required activation energy for reactions in theform of mechanical energy, at modest temperatures and pressure,and without solvents. Milling conditions should be chosen care-fully because frequently there is an optimum value for millingparameters both with respect to milling effectiveness and energyconsumption.

Milling creates its own chemical pathways. For chlorinated andbrominated pollutants, non-oxidizing reagents transfer electronsto pollutant molecules, causing rupture of the carbon halogen bond;while the high energy milling of oxidant reagents produces newcrystals surfaces with active centers, which oxidize the carbonstructure and induce halide release. On the other hand, fluorinatedcompounds with potassium hydroxide are unique and appear tofollow a non-redox degradation mechanism. A general understand-ing of reaction mechanism under high energy milling has beenachieved, but many details require further study.

MC has the potential to be a versatile technology usable withmany different kind of solid waste in effective, safe, and cheap man-ner. However, at the moment, additional studies are necessary tounderstand thoroughly the pollutant behavior during high energymilling in solid phase reactions, when they are in pure form or incomplex contaminated waste matrices. In particular, the effect ofdifferent type of milling actions (i.e., different devices) has not been


investigated in detail. All these aspects should improve the energyrequirements of the MC treatment.

Acknowledgements

This study was supported by the National High TechnologyResearch and Development Program of China (2013AA06A305), theProgram for Changjiang Scholars and Innovative Research Team inUniversity (IRT1261), and the Collaborative Innovation Center forRegional Environmental Quality.

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24


April 2013 EPA0189

Appendix 3: UN assessment of ball milling treatment system.

1

GEF/UNDP Project on Environmental Remediation of Dioxin Contaminated Hotspots

in Viet Nam

Independent Expert Evaluation ofThree Pilot/Laboratory Scale Technology Demonstrations on Dioxin Contaminated Soil

Destruction from the Bien Hoa Airbase in Viet Nam.

R. J. Cooke

Man-West Environmental Group Ltd.

March, 2015

2

Executive Summary

Introduction

1. The following provides an elaborated Executive Summary of an independent internationalconsultant’s report on the evaluation of three candidate technologies demonstrated on a laboratory orpilot scale for the remediation of soil contaminated with dioxins/furans (PCDD/F) and otherchlorinated organic chemicals as a result of the handling and storage of dioxin contaminated defoliantherbicides during the period of armed conflict in Vietnam between 1965 and 1972. The threetechnologies involved are: i) several bio-chemical treatment strategies proposed by HPC-Envirotec;ii) the mecano-chemical dehalogenation (MCDTM) ball milling technology proposed byEnvironmental Decontamination Limited (EDL); and iii) an enhanced batch thermal desorptiontechnology named Matrix Constituent Separation (MCSTM) proposed by Thermodyne TechnologiesInc. (TTI). The demonstration program was undertaken by these companies substantially at theirown expense at locations outside of Vietnam. They were done in cooperation with the Office 33within the Vietnam Environmental Administration (VEA) and Ministry of Natural Resources andEnvironment (MONRE) of the Peoples Socialist Republic of Vietnam who supported acquisition oftest materials and analytical characterization. The national participation in the demonstration programwas financed by the Global Environmental facility (GEF), working though the United NationsDevelopment Program (UNDP) as an Implementing Agency. It was a closing activity for a GEF-4full scale project begun in 2009 which was intended to address dioxin contamination issues inVietnam A major focus of this overall project was the identification and demonstration of appropriateremediation technologies for the elimination of dioxins from these “hot spots “, specifically those atthree major and active airfields.

Background and Context

2. This particular demonstration program grew out of an earlier larger demonstration programundertaken in 2012 where the EDL MCDTM technology was demonstrated at Bien Hoa using a basicfull scale configuration to process 100 t of contaminated material of various concentrations,excavated directly from the site. This demonstration successfully remediated initial soilconcentrations <30,000 ppt TEQ to below the specified acceptance level of 1,000 ppt TEQ but wasidentified as having limitations above this input soil concentration level. It was concluded that theselimitations could potentially be addressed by pilot testing to optimize the process operatingconditions, something the company offered to do if well characterized soil test samples wereprovided. This concept was subsequently broadened by Office 33 and UNDP to solicit expressions ofinterest from other technology suppliers globally in undertaking such pilot scale demonstrations withthe result being the selection of the two additional companies for the current pilot demonstrationprogram. The program itself was initiated in late 2013 and implemented in 2014 and early 2015. Partof this program as reported on here was its independent evaluation undertaken by an internationalexpert contracted through UNDP.

3. The GEF funded work on this project in Vietnam is part of a broader global initiative by the GEF andits implementing agencies to stimulate the development of environmentally sound and cost effectivePOPs/chemicals destruction and remediation technologies for application in addressing the stockpilesand waste requirements of international conventions such as the Stockholm Convention. Therefore,in addition to assisting Vietnam in its work to address dioxin contamination, the project andspecifically the demonstration of remediation technologies will be evaluated in the context of this

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broader global objective. This is particularly important at this time when the GEF and itsimplementing agencies are making significant investments in this area globally.

4. As general background and to frame the context of this particular program, work in addition to theabove mentioned full scale demonstration of the MCD technology has focused on a number of keyareas relating to: i) defining the site contamination problem to be addressed; ii) establishing siteclean-up and technology environmental performance standards that would apply; iii) development oftechnology demonstration practices for future national use, iv) exploring the potential for transfer andacquisition of appropriate technologies in the country; v) developing overall site clean-up strategiesfor adoption as the country moves forward addressing the issue on a practical level. The key findingsin these areas which inform and potentially will be informed by the current work are: As a general characterization the dioxin contaminated site issue in Vietnam is complex and

characterized by i) relatively modest average overall dioxin contamination levels but with a widedistribution of contamination levels distributed in a generally random fashion and with extremesin close proximity over a large area and to significant depth; ii) contaminated locations in closeproximity to intensive current and future land uses with historical health impacts and environmentrelease; and iii) a range of other secondary contaminants characteristic of highly disturbedindustrial activity which also potentially present environmental and health risks, and limit futureland use.

Two relevant national soil quality/clean-up standards have been established including a 2009standard for “hot spots” that set target clean-up standards of 1,000 ppt TEQ for soil and 150 pptTEQ for sediment, and a general soil quality 2012 standard that covers six land uses includingindustrial/commercial set at 1,200 ppt TEQ, recreation at 600 ppt TEQ, urban land used(residential) 300 ppt TEQ and rural land use (agricultural) at 120ppt TEQ. Point source andambient air and water standards for treatment facilities have also been established, for PCDD/Fconsistent with international standards.

In addition to meeting the above performance standards through demonstration programs, animportant objective in selecting remediation technologies is its suitability for commercial transferand acquisition by Vietnamese entities for future operation in the country for dioxin and othertypes of contaminated sites.

An overall strategic view has evolved recognizing that a variety of technologies may beappropriate given the range of land use standards established, variability of the contaminationencountered and level of urgency applicable to particular sites including re-developmentpressures.

Demonstration Program Design and Preparation

5. The overall design of the demonstration program is documented in three activity Terms of Reference(TOR) for contracted work that have been reviewed under the headings: i) Test Soil SampleExcavation, Preparation, Analytical Screening, and Disposition; ii) Baseline Test Soil SampleCharacterization; and iii) Technology Demonstration Scope/Performance Criteria Assessment. Thefindings indicate that the process of identification, excavation, screening and assembling consistenttest soil samples in three target ranges of PCDD/F concentrations (low- 10,000-15,000 ppt TEQ,Medium –approximately 30,000 ppt TEQ and high approximately 70,000 ppt TEQ) was wellmanaged and successful. Initially it was not possible to obtain this result directly from excavated soilbut accessing an extremely high concentration store of segregated material in the Bien Hoa Z1 arealandfill allowed a process of mixing to be used to manufacture the required test sample material. Six20 kg lots of the low concentration material, three 20 kg lots of medium concentration material andone 20 kg lot of high concentration material were assembled and distributed to the three technology

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partners as required. The comprehensive baseline analysis of samples from each lot was undertakenby an international laboratory and validated as providing consistent and representative test soils interms of PCDD/F concentration to actual field conditions although they were not necessarilyrepresentative for other contaminants. The evaluation of the technology demonstration scope andspecified performance criteria requirement indicated that while somewhat aspirational it could begenerally applied to the actual pilot laboratory scale demonstration with some qualification on what isrealistic and with flexibility in interpretation.

Evaluation Methodology

6. The overall methodology and approach adopted in undertaking the individual pilot/laboratorytechnology demonstration evaluations in the following sections incorporates the requirements definedin the scoping TOR to place the evaluation work within a common and consistent framework whichsystematically addresses issues identified by national experts and stakeholders, as well as addressissues that are significant to GEF and implementing agencies. The methodology framework used hasthree parts covering ; i) technology background, demonstration work plan and any relevant aspects ofthe applicable partnership agreement; ii) the direct pilot/laboratory scale technology demonstrationresults evaluated against the “Evaluation Criteria” defined by Office 33/UNDP as applicable; and iii)assessment of the extrapolation of the technology demonstration results for a potential full scalecommercial operation as proposed by the technology partners in their technical reports.

HPC-Envirotec Demonstration Evaluation

7. HPC-Envirotec demonstration involved a series of five bio-chemical soil treatment strategies appliedas experimental laboratory treatability screening tests. These included two reductive basedtreatment strategies involving a Zero Valent Iron (ZVI) with nutrient or electron donor additives, twooxidative based treatment strategies involving persulfate additions (including one supplemented by anelectron donor addition), and one biological treatment involving proprietary additives marketed by thecompany.

8. Within the overall scope of the demonstration program the test soil samples were in the “low”concentration (<15,000 ppt TEQ) category ranging from 11,200 to 15,000 ppt TEQ which uponmixing into a common sample was assumed to have an average concentration of 13,330 ppt TEQ.The results indicate that while some reduction in PCDD/F content occurs with all five treatmentstrategies this is relatively modest in all cases after 3 months of treatment and still substantially higherthan the minimum target soil quality level of 1,000 ppt TEQ. For the three treatment strategiescontinued for 6 months, the results for all but the aggressive oxidative de-chlorination treatment withpersulphate showed no further reductions. The persulphate treatment shows reductions down to alevel of 1,475 ppt TEQ) which approaches but is still above the target minimum soil quality levelusing output results from a European laboratory. The Office 33 designated independent laboratoryresults showed less reduction (5,890 ppt TEQ). However, in either case if projected to a longer timeit was predicted that concentrations would reach the required level albeit after a number of months.In summary, it appears that the impact of reductive and biological treatments is modest while theimpact of aggressive de-chlorination treatment with persulphate appears to sustain the reduction inPCCD/F concentration suggesting that continued treatment could potentially achieve betterperformance.

9. The results for 2,4-D/2,4.5-T show reductions for all treatment strategies with the best resultsobtained for treatment strategies involving persulphate based treatment strategies. Reductions were

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achieved with several of the other biological and combined bio-chemical treatment strategies but as inthe case of PCDD/F the effectiveness was primarily early in the treatment time period so it appearsthat these treatment strategies may have a relatively short effectiveness life. In the case ofchlorophenols, reductions are achieved for all treatment strategies. No impacts on arsenic or otherheavy metals were expected and this was not assessed.

10. All the treatment strategies only achieved modest remediation efficiencies (RE) levels for PCDD/Fexcept the aggressive persulphate based treatment strategies which after 6 months approached a 90%level when the European laboratory results were used but remained less than 60% for the Office 33designated laboratory results. RE values achieved were better for a number of treatment strategiestested with respect to acid herbicides with the biological treatment strategy showing RE’s over 90%and the persulphate treatment strategies over 99%.

11. The primary overall conclusions of the evaluation are:

The best treatment strategy tested involved an oxidative chemical de-chlorination processrequiring aggressive additions of persulphate which offers potential to achieve the requiredminimum acceptable PCDD/F soil concentration level and acceptable REs, but this needs to beevaluated in the broader context of commercial and logistical viability given the large volume ofchemical additions required.

The technology needs to be validated through further development and demonstration asproposed by the company including a mandatory field pilot study, something that may bepotentially provided through bi-lateral support identified by the company and could also beintegrated with possible field technology demonstration work on similar technologies beingdiscussed for a parallel GEF-4 POPs pesticide project in Vietnam.

Subject to further validation, the technology is projected by HPC Envirotec as offering costadvantages (estimated to be in the range of 60-200 €/t) since theoretically it is an in-situtechnology not requiring excavation at least for shallow surficial contamination. However, it isalso noted that it could be applied to excavated material in contained cells to address deeper ormore complex situations. It can be speculated that excavation could also lead to better treatmentresults, because the soil could be mixed more easily with the chemical and microbiologicalingredients.

The technology should be readily applied in Vietnam using national expertise and resources aftera period of training and international supervision, and would also be a technology that should beamenable to acquisition by or transfer to a qualified Vietnamese entity for long term operation,again qualified by the need for substantially more demonstration and performance improvement,something that the company has indicated a strong willingness to pursue.

It is recommended that if there is to be further consideration of the technology, the Governmentof Vietnam engage in discussion with HPC Envirotec and potential donors and critically assessthe cost benefit of collective funding of further development and demonstration work with fullconsideration of the current technical performance results.

EDL MCDTM Technology Evaluation

12. The demonstration undertaken by EDL using its MCDTM ball milling technology is essentially acontinuation of the 2012 full scale demonstration work undertaken at Bien Hoa with the purpose tovalidate its effectiveness at higher PCDD/F soil concentrations than it had achieved previously. Thisinvolved pilot testing of soils classed as of medium concentrations (range of 30,000 ppt TEQ) and ofhigh concentrations (range of 70,000 ppt TEQ) should cover all reasonable bulk soil concentrations

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likely to be encountered in a large scale commercial application. Three tests were done at eachconcentration level in 60 minute resident time runs using a single full size MCD reactor with theoperational variables investigated being rotational speed, residence time, and impact of severaladditives.

13. The PCDD/F test results for the medium concentration soil showed that overall progressive PCDD/Freduction/destruction was occurring at the four assessed time intervals and achieved concentrationlevels below 1,000 ppt TEQ in all runs and in two runs achieved levels below 200 ppt TEQ with thebest result being 110 ppt TEQ when a TiO2 reagent was used. The results for the high concentrationsoil showed that the best performance where a concentration level below 1,000 ppt was achievedwithout additives. Somewhat poorer performance that was approaching 1,000 ppt TEQ occurred withthe same operating conditions but with quartz additions. Worse performance occurred with Run 5where the RPMs were reduced, demonstrating the sensitivity of high concentration performance tothis operational parameter. Overall the results demonstrated that the nominal medium range of soilsshould be well within the capacity of the process to achieve the minimum acceptable soil quality withflexibility to go to levels below any applied in Vietnam for reasonably contemplated land use. Forthe high concentration range which generally would be a relatively infrequent occurrence in practiceif preparatory soil mixing was employed show that the process can achieve the required level andwould likely do so consistently with adjustment of additives and resident times, while maintaining thehigher rotational speeds. This offers a speciality capability for treating the relatively small quantitiesof extreme concentrations periodically encountered.

14. For other secondary chlorinated organic contaminants, the results generally tracked those for PCDD/Fwith reductions of dioxin-like PCBs down to negligible levels, 2,4-D/2,4.5-T showing significantreductions for the medium concentration runs particularly with TiO2 enhanced de-chlorination butless for higher concentrations and for chlorophenols. Overall, these contaminants are reduced tobelow international screening standards at least for commercial/industrial land use. In the case ofarsenic and heavy metals, the process does not appear to have any significant impact as anticipatedalthough this is being further investigated by the company and a potential future refinement might bethe use of zeolite to immobilize arsenic.

15. The PCDD/F RE performance achieved was in the range of 97. 4% to 99.6% for medium soilcontamination levels with the best results achieved with the TiO2 additions, and for highconcentration soils the range of RE’s was 97.8% and 98.7 % with high rotational speed runs. TheREs for 2,4,-D and 2,4,5-T approached or exceed 99% for the medium PCCD/F soil concentrationruns and with the exception of the low RPM run the RE performance is in the 96 % to 98% range for2,4-D and 98% to 99 % range for 2,4,5-T on the high PCCD/F soil concentration runs. Overall, theREs achieved are considered effective process DEs with actual destruction through de-chlorinationoccurring and being sustained with time. The addition of residence tine should allow the process toachieve that lower soil concentrations and higher RE or process DEs are achievable.

16. EDL has confirmed the applicability of its earlier proposal for a full scale commercial plant involvinga two train, ten reactor configuration MCD plant (5 reactors per train) operated in series as presentedin the 2012 demonstration report. In terms of capacity this would provide an estimated capacity of 16t/hr or up to 50,000 t/year for soils in the 15,000-20,000 ppt TEQ range. This would cover the largemajority of soils expected to be encountered particularly if the recommended pre-preparationhomogenization of excavated soils was incorporated. For higher concentrations there would beanticipated capacity reductions be roughly prorated for higher concentrations as may be encounteredon a case by case basis due to higher residence times. Overall the projected full scale configuration

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should offer an attractive capacity for a large scale remediation project on sites such as Bien Hoa orPhu Cat. It would also potentially offer the flexibility to handle special cases of higher concentrationmaterial hot spots identified at the level of detailed site assessment required for a large scaleremediation project as well as dealing with the already stockpiled and contained (in landfills ortemporary containment structures) at Bien Hoa in the Z1 and Pacer Ivy areas. It would also offer apotential destruction option for contaminated GAC from other sources.

17. One critical area that while addressed in the discussion of a full scale configuration but furtheremphasized here is the need to incorporate and demonstrate a rigorous system of dryer stack andgeneral fugitive emission capture/treatment recognizing that this could not be comprehensively donein either the 2012 full scale demonstration or the current pilot scale demonstration work. With this inmind an overall recommendation of this evaluation is that the full scale commercial application of thistechnology include a start-up qualification or “proof of performance” program covering technical andenvironmental performance, inclusive of PCDD/F and particulate emissions from the dryer, fugitiveemission (particulate and VOCs) at potential point release sources, and ambient indoor andsurrounding air quality. This would be sustained by an appropriate operational monitoring programincluding rapid soil input/output screening and environmental monitoring as done duringqualification.

18. In terms of indicative cost, EDL confirmed the applicability of the US$380/t cost quoted in the itsreporting on the 2012 demonstration inclusive of self-contained power supply and application to bulksoil concentrations <30,000 ppt TEQ. Likewise an indicative capital investment of US$5.0 millionexclusive of slab, housing and power supply would apply to the proposed configuration.

19. Operationally the technology is moderately complex but well within national technical capacity andhuman resource availability as demonstrated in the 2012 program. Additionally, it would also be atechnology that should be amenable to acquisition by or transfer to a Vietnamese entity for long termoperation through conventional and transparent commercial business arrangements, something whichEDL indicates an interest in pursuing with interested and qualified parties.

20. In summary EDL’s MCD technology is considered technically qualified for large scale remediationapplications on the large majority of PCDD/F contaminated soil likely to be encountered for even themost restrictive land use and as such should be considered in any commercial opportunities that ariseincluding for pending remediation work at Bien Hoa, other sites in Vietnam and likewise would becandidate for POPs contaminated sites being addressed by the GEF globally.

TTI MCSTM Technology Evaluation

21. The MCSTM Technology demonstrated by TTI is nominally classed as a non-combustion remediationtechnology but is essentially a pre-treatment technology that captures and concentrates the POPs andother organic and volatile inorganic contaminants for onward management by another true destructiontechnology. It is described as a portable (transportable), modular, low profile batch thermal treatmentsystem that accomplishes desorption of organic and volatile inorganic compounds from a solid orsemi-solid matrix utilizing the combination of infrared heating, convective/conductive heat transfer,heated air stripping effect, vacuum conditions, fluidized bed, boiling point reduction and chemicalvolatilization. It was the technology that successfully remediated 24,000 t of dioxin contaminatedmaterial in a wide range of concentrations from the clean-up of the Johnson Atoll storage site in 2004to levels below 1,000 ppt TEQ. This site was used as a repository for Agent Orange and otherdefoliant herbicides removed from Vietnam by the US government.

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22. The pilot demonstration was done on a thermal treatment unit configuration with two trays in thenormal full sized configuration for a single thermal treatment train and effectively was a full sizedemonstration except for the actual test sample size (approximately 20kg rather than 4-5t traycapacity). Three test runs were done on each of the “low” concentration soil test samples supplied bythe Office 33 PMU. The results for the three pilot test runs show that there was a dramatic removal ofPCCD/F from the all test samples (both sample boxes for each test) with residual PCDD/F beingbetween 1 and 2 ppt TEQ. Somewhat higher levels of residual PCCD/F were observed in thepreliminary baseline test results but typically not more than 15 ppt TEQ which is again very lowrelative to any contemplated standard. The results for dioxin-like PCBs, 2,4-D, 2,4.5-T, andchlorophenols show that these contaminants are almost totally removed with only trace amountsremaining well below any soil quality standards that might be applied. The RE performance showsthat in all test runs greater than 99.99% is achieved for PCDD/F as well as the secondary chlorinatedorganic contaminants of interest. Overall these results demonstrated that the technology offers thecapability to almost completely remove the primary contaminants of interest from the subject soilsand would also potentially offer a capability to tailor the remediation result to various soil qualitystandards should that be desired.

23. The results for arsenic based on a comparison of baseline input analysis concentrations and the outputconcentrations indicate that the thermal treatment process appears to alter the nature of arsenicconcentrations through effectively reducing the organic arsenic component levels to non-detectablelevels. A similar effect was observed on inorganic As (III). However a general increase occurred ininorganic As (V) and in total As, as well as recoverable As. These results suggest that the thermaltreatment process may have a non-beneficial effect on the potential toxicity of the As levels. In thecase of other heavy metals no impact on these was noted.

24. While the MCSTM process is demonstrated as a highly effective remediation technology, it cannot beconsidered to qualify as a POPs destruction technology per say and based on this demonstration stillrequires further work to fully define the fate of all removed critical contaminants in an accurate massbalance. However the limited analytical results applicable to GAC capture and stack emissionssuggests good capture capability similar to that proven on a previous major project on like materials.Having said that the technology in combination with a high destruction efficiency technology toprocess the media that captures the removed PCDD/F and other chlorinated organics would havereasonable prospect of being part of an integrated system that would meet the 99.99% DE levelrequired in Convention and GEF guidance documents. TTI itself indicates that a separate dedicatedtrain could be used to extract accumulated contaminants from GAC material and destroy the resultingvapour phase in a stack thermal oxidizer (incinerator) as was done at Johnson Atoll. However, thiswould require a comprehensive full scale trial such as would be envisioned as required in any event atthe start up/qualification stage of a major commercial project.

25. TTI quotes a variety of capacity scenarios based on the incremental and trained nature of thetechnology. A single 4-5 t per dual treatment tray configuration assuming a 4-5 hour batch treatmenttime is estimated to equate to approximately 1.0-1.25 t/hour per treatment unit which is projected to amean annual capacity of 6,200 t/year per treatment unit. Recognizing that the capacity would betailored to the site specific requirement through an optimum number of treatment units configured inparallel, a configuration of eight parallel units would offer a capacity that would typically average50,000 t/year. This should offer an attractive capacity for a large scale remediation project on sitessuch as Bien Hoa or Phu Cat.

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26. In terms of indicative costs TTL provide a qualified number of US$500/t indicating this will bedependent on a number of project/client specific variables. Likewise the capital investment alsodepends on a number of site and project specific variables but a number of US$1million per MCSTM

module would generally apply with a basic 8 MCS unit system being US$8 million, noting that therecould be significant capital cost savings with larger MCS System configurations.

27. Operationally the MCSTM technology is moderately complex but well within national technicalcapacity and human resource availability assuming technology partner training and technical support.It should be amenable to acquisition by or transfer to a Vietnamese entity for long term operationthrough conventional and transparent commercial business arrangements, something that TTIindicates an interest in principle in pursuing.

28. In summary TTI’s MCSTM technology is considered technically proven for remediation applicationson the PCDD/F contaminated soil up to 15,000 ppt TEQ and would offer a very high prospect ofqualifying for higher concentrations con a commercial basis. Given this, it is highly recommendedthat TTI and Office 33 pursue this in the immediate future using characterized soils obtained underthis GEF funded project with such an initiative being beneficial to all major stakeholders includingthe GEF in respect to POPs contaminated sites being addressed by the GEF globally. It is understoodthat UNDP are facilitating such arrangements as a follow up activity.

Conclusions and Recommendations

29. The following summarizes the principle overall conclusions and recommendations that flow from thisindependent evaluation:

The GEF financed and Office 33 managed program was generally successful in demonstratingthree non-combustion technologies that have potential for application in Vietnam on PCCD/F andother POPs contaminated sites, as well as globally for POPs and other chemicals contaminatedsites of interest to the GEF in its mandate to seek global environmental benefit. As such itprovides an excellent initiative to close this GEF project on. The only major constraint on itbeing fully successful was that the test programs for two of the technology demonstrations (HPCEnvirotec and TTI) were truncated due to the time constraints imposed by the termination of theGEF project and both could have potentially achieved more definitive results with more time andin one case being supplied with a broader range of test soil concentrations.

The results indicate that two of the demonstrated technologies (EDL MCDTM and TTI MCSTM)are essentially technically and commercially qualified to undertake full scale remediation projectsin Vietnam on a commercial basis and should be considered as cost effective, environmentallysound candidates for near and long term commercial opportunities for the pending major “hotspot” remediation projects. The one qualification applicable to both is that they demonstrateremediation and environmental performance during start-up “proof of performance” testing on afull scale commercial unit at the start of such a project, something that any prudent commercialcontracting of such technologies would do in any event.

The additional qualifications for the TTI MSCTM technology is that i) it would be beneficial toundertake demonstration of the expected good remediation performance on higher concentrationmaterials which TTL has undertaken to do on test samples prepared with GEF funding asrequested from Office 33, and which UNDP has agreed to facilitate the supply of through; and ii)

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that further work include determination of the fate of contaminants extracted from the soil andpossible impacts on arsenic form and concentration.

The HPC-Envirotec demonstration work is recognized as being a different stage of developmentrelative to the other two technologies with the next step being moving from a laboratorytreatability testing stage of various bio-chemical treatment strategies to undertaking a longer termfield pilot program on what are most prospective options. The feasibility of doing this should bepursued, potentially using bilateral funding and/or perhaps in association with parallel field pilotstudy work involving similar techniques in another GEF-4 project on POPs pesticides, and arecently initiated MND research and development initiative at Bien Hoa.

The program also demonstrated the positive application of lessons learned from the previousdemonstration work in relation to the soil sampling and characterization procedures to be appliedto the acquisition of test sample materials. The process of identification, excavation, screeningand assembling consistent test soil samples in three target ranges of PCDD/F concentrationsundertaken by national experts was well managed and successful. As such this should serve toinform the development of practices and procedures used in future demonstration programs.

Based on the above experience, additional knowledge respecting the nature of soil contamination,its distribution and overall localized nature of contamination extremes on the Bien Hoa site wasobtained which further underlines the variability of as excavated soils and the potential value inimproving the level and predictability of technology performance as a general principle through apreparation stage involving mixing and homogenization.

As a general observation, while the demonstration program shows that at least two fullycommercial technologies are available to remediate PCDD/F contaminated soils to any land useacceptance criteria that might be practically sought in terms of organic contaminants, the inherentnature the hot spot sites is that they are complex highly disturbed industrial sites containing avariety of other secondary contaminants that will likely limit future land use toindustrial/commercial land use in any event on the main areas of former defoliant management.

With respect to the legitimate priority expressed by national stakeholders respecting nationalparticipation in the commercial application of remediation technologies, all three demonstratedtechnologies can be readily applied in Vietnam using national expertise and resources after aperiod of training and with some initial international technical support, and would also betechnologies that should be amenable to commercial arrangements supporting their acquisition byor transfer to qualified Vietnamese entities for long term operation,

The current evaluation is not intended to be considered comparative but as a general overarchingobservation, there are a number of areas of potential synergy between thetechnologies/techniques demonstrated such that their integrated application in the near and longerterm would be beneficial, particularly if established and sustained in the country on a commercialbasis. There is an immediate place for direct invasive interventions in major hot spots and landrequiring rapid remediation for near term redevelopment, a role that either or both the MCDTM

and MCSTM technologies could fill This includes working cooperatively given the large volumeprojects and short time frames that could be financed in the near term particularly at Bien Hoa.This could also involve distributions of responsibilities depending on the concentration levelsinvolved and potentially management of contaminated residuals, including contaminated GACand material of extremely high PCDD/F concentration. The role of bio-chemical treatment

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strategies such as proposed by HPC Envirotec has a longer term application characteristic andwould potentially have a place on the periphery of the large heavily contaminated sites and onpotentially numerous smaller more widely distributed PCDD/F contaminated sites that are andwill continue to be identified around the country.

In conclusion, the current demonstration program can be considered very successful and usefulapplication of effective adaptive management by the UNDP and Office 33 project team inutilizing GEF resources for both national and global benefit with the results being recommendedfor wide dissemination through UNDP and the GEF, In that regard, a number of GEF projectsunder preparation or currently initiating implementation will find the results of this workimmediately applicable.

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Table of Contents

Executive SummaryList of Abbreviations and AcronymsList of Tables and Figures

1.0 Introduction and General Background……………………………………………………………..…16

2.0 Technology Demonstration Background and Scope……………………………………………….. 19

3.0 Current Technology Demonstration Background and Scope………………………………………...23

4.0 Evaluation Methodology………………………………………………………………………… …40

5.0 HPC Envirotec…………………………………………………………………………………………43

6.0 Environmental Decontamination Ltd……………………………………………………………....,.57

7.0 Thermodyne Technologies Inc…………………………………………………………………….....74

8.0 Discussion of Results and their Significance………………………………………………………..90

9.0 Overall Conclusions and Recommendations…………………………………………………………99

Annexes

Annex1: Task Specific Terms of Reference for the Pilot Demonstration Program…………………..102

1.1 Soil Preparation for Technology Demonstration

1.2 Laboratory Analysis of Dioxin for Technology Demonstration

1.3 Treatability Study of Dioxin Remediation Technology to Treat Soil/sediment

in Bien Hoa Airbase, Vietnam

Annex 2: Record of Manufactured Soil Sample Lots Prepared by VRTC and their Distribution….....122

Annex 3: Summary Pilot/Laboratory Technology Demonstration Evaluation Results……………….129

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List of Abbreviations and Acronyms

2,4-D 2,4-Dichlorophenoxyacetic Acid

2,4,5-T 2,4,5-Trichlorophenoxyacetic Acid

AO Agent Orange

APC Air Pollution Control

As Arsenic

Ca Cadmium

Cu Copper

DDT Dichlorodiphenyltrichloroethane

DE Destruction Efficiency

DRE Destruction Removal Efficiency

EDL Environmental Decontamination Ltd.

EOI Expressions of Interest

EOX Extractable Organic Halide

ESM Environmentally Sound Management

FAO United Nations Agricultural Organization

GAC Granulated Activated Carbon

GEF Global Environmental Facility

GEFCEO Global Environmental Facility Chief Executive Officer

GEFSTAP Global Environmental Facility Scientific and Technical Assessment Panel

GVN Government of Vietnam

ha Hectare

HCH Hexachlorocyclohexane

HTI High Temperature Incineration

IPTD In-Pile Thermal Desorption

MCDTM Mecano-Chemical Dehalogenation

MCSTM Matrix Constituent Separator

MND Ministry of National Defence

MONRE Ministry of Natural Resources and Environment

NGO Non-government Organisation

PAH Polyaromatic Hydrocarbons

Pb Lead

PCP Pentachlorophenol

pg picograms

POPs Persistent Organic Pollutants

PCB Polychlorinated Biphenyl

PCCD/F Polychlorinated dibenzo-p-dioxins/ Polychlorinated dibenzo-p-furans

PD Project Document

ppm Parts per Million

ppt Parts per Trillion

PMU Project Management Unit

RE Remediation or Removal Efficiency

SC Stockholm Convention

t Metric ton

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TCDD Tetra chloro dibenzo-dioxin

TEQ Toxic Equivalent

TOC Total Organic Content

TOR Terms of Reference

TTL Thermodyne Technologies Limited.

VAST Vietnamese Academy of Science

VEA Vietnam Environmental Agency

VRTC Vietnam Russia Tropical Centre

UNEP United Nations Environmental Programme

UNDP United Nations Development Programme

UNIDO United Nations Industrial Development Organization

USAID United States Agency for International Development

USEPA United States Environmental Protection Agency

Zn Zinc

ZVI Zero Valent Iron

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List of Tables and FiguresTables

Table 3.1 Contaminated Soil from Bien Hoa Excavated and Prepared for Use in the Pilot TechnologyDemonstration Program

Table 3.2 Summary of Baseline Test Soil Samples, PCCD/F, Dioxin-Like PCBs, Acid Herbicides, Chlorophenols,Organic Arsenic

Table 3.3 Summary of Baseline Test Soil Samples - Soil Properties Total Organics and Inorganics/metalsTable 3.4Comparison of As-excavated Soil Analysis from the 2012 Program with the Current Manufactured Test

Soil Samples

Table 5.1 HPC Envirotec - Summary of Laboratory Test Results for Short Term Tests Terminated after 3 Monthswith Analysis HPC Designated Laboratory

Table 5.2 HPC Envirotec - Summary of Laboratory Test Results for Three Extended Term (6 Month) Tests withAnalysis from both HPC and PMU Designated Laboratories

Table 5.3 HPC Envirotec - Consumable Use for Extended Treatment Strategies on Samples MP-2.1, MP-2.2 andMPD-2.5

Table 6.1 EDL - Work Plan Pilot Test ConditionsTable 6.2 EDL - Summary of Pilot Test Results for “Medium” and “High” Concentration Test Samples – Primary

Organic Contaminants (PCDD/F, Dioxin-Like PCBs. Acid Herbicides and Principle Chlorophenols)Table 6.3 EDL - Comparison of Baseline Heavy Metals Analysis (Sample 0314VN2.3) and Output

Analysis for Run 2Table 7.1: TTL - Pilot Test Conditions

Table 7.2: TTL- Summary of Pilot Test Results – Primary Organic Contaminants (PCDD/F, Dioxin-Like PCBs.

Acid Herbicides and Principle Chlorophenols) and Heavy Metals

Table 7.3 - Estimated Energy and Resource Requirement for MCST Full Scale Operation

Figures

Figure 3.1 Overview of Bien Hoa Air Base indicating the Pacer Ivy and Z1 Areas where Test Soil was

Sourced

Figure 3.2 Excavated Soil Sample Locations – Pacer Ivy Area Bien Hoa Airbase

Figure 3.3 Excavated Soil Sample Locations – Z1 Area Bien Hoa Airbase

Figure 5.1 Projection of Treatment MP-2.2 - Based on HPC/SGS Analysis and AsureQuality Analysis

6. Environmental Decontamination Limited Pilot Demonstration

6.1 Part 1 Technology Background and Demonstration Implementation

6.1.1 Technology Partner Background

General and Business Scope: Environmental Decontamination Limited (EDL) is a contaminated siteremediation company based in New Zealand and operating globally through representative andlicensee/partners in South East Asia, Western Europe, Southern Africa, and North America. Thecompany provides both proprietary technology, namely the patented MCD Technology ball millingprocess as demonstrated in this work, and turn-key operational site remediation services. The company isowned by a New Zealand based engineering, construction and waste management company (MANCO)and a Hong Kong based investment and trading company (EDL (HK) Ltd.).

As described above the EDL MCD technology was selected for a full scale trial at Bien Hoa in 2012.Involvement in the current demonstration results from discussion with UNDP, Office 33 and arepresentative of GEFSTAP at a concluding workshop in January 2013. This resulted in a proposal beingsolicited by the Office 33 PMU and made by EDL to undertake pilot testing on higher soil concentrationsthan those for which uncontested results were obtained in the 2012 work. The following evaluation isbased on the content of this proposal47, the subsequent partnership agreement signed with the Office 33PMU48, and the final report on trials involving a series of pilot scale test runs done in November 2014 at afacility in South Africa as formally submitted on February 24, 201549 and information conveyed by thetechnology partner at the final project technical meetings and workshop held in Hanoi March 18-19,2015.

Remediation technology application experience base: EDL reports a list of eight projects involving 14MCD plant units addressing a range of site contamination issues globally including POPs and chloro-organic pesticide contamination. Additionally a number of pilot trials are referenced specific to PCDD/Fincluding the current and 2012 tests on defoliant herbicide dioxin contaminated soil and on PCDD/Fcontaminated granulated activated carbon (GAC) and steel mill fly ash in Western Europe.

6.1.2 General Technology Description and Categorization

General description and technology type: The type of technology being demonstrated is tribology based,involving mecano-chemical de-halogenation created by high speed collisions of steel balls with thecontaminated soil such that free highly reactive surfaces are generated, a highly localized triboplasma iscreated giving energy for chemical reactions, and free radicals also being created which can then go on toreact with neighbouring compounds. In the case of contaminant compounds containing chlorine, when aphysical energy greater than a specific strength of the chemical bond involved is exerted, the process willbe chemically activated (as chlorine and carbon bonding is weaker) resulting in chlorine and carbon beingseparated to provide a de-chlorination reaction. In the MCD configuration, the process is continuous withthe variables being feed rate, resident time, ball numbers and weight, and rotational speed. The currentdemonstration used a single reactor although in a full scale configuration typically 4 to 5 larger reactors

47Proposal letter for pilot application of MCD Technology to Contaminated Soils from Bien Hoa, from EDL

addressed to PMU Project Manager, June 18, 2013.48 Agreement for Additional Technology Demonstration Trials between Vietnam Dioxin Project PMU and EDL,October, 201449 “MCD Technology Demonstration Environmental Remediation of Dioxin Contaminated Hotspots in Vietnam”,EDL, February 23, 2015

are trained in series with additional trains either operating in parallel or if longer resident times arerequired again in series. It is classed as a non-combustion technology with both capability for soilremediation and chlorinated chemical destruction such as required under Article 6 of the StockholmConvention.

Commercial Status: Generally, the technology is considered commercial and is offered as such. However,as with most such technologies it should be demonstrated and qualified for site and contaminant specificapplications as part of a remediation project or on a pilot plant scale. The nature of the currentdemonstration is not considered commercial, although at the scale used it could have application toprocess smaller quantities of speciality chlorinated wastes.

Maturity: Overall this is considered a relatively mature technology with a significant R&D effortsupporting it and an expanding commercial experience base. Having said that, it’s complete potential interms of the materials and contaminants it can address and optimization of performance and operatingconditions is the subject of ongoing investigation.

Application to PCDD/F Contamination: Application experience of the EDL MCD technology to largescale PCDD/F contaminated sites is limited, as in fact the case for virtually all non-combustion processtechnologies50. However, a basic full scale configuration of the technology has successfully beendemonstrated on 100 t of material at Bien Hoa up to soil concentrations of 30,000 ppt/TEQ. As indicatedin the following, the current pilot demonstration shows good performance at over 70,000 ppt TEQ andpilot demonstrations have also demonstrated destruction capability when applied to PCDD/Fcontaminated GAC and fly ash.

Application Type: The technology is an ex-situ technology that requires excavated and bulk packagedmaterial to be bought to a plant set up for purposes of its treatment, normally on or adjacent to the siteunder remediation. Preparation requirements as a minimum would involve screening/size reduction anddrying with a recommended homogenization step to ensure relatively even distribution of contaminantconcentration. The technology is transportable and suitable to establishment on site subject to availabilityand/or construction of basic infrastructure (access, cover, utilities etc.)

Application Timeframe: The technology provides immediate processing results upon application at ratesup to8t/hr./hr for a single increment full scale unit with the overall time frame being a function of volumerequirements to be processed and number of parallel plants that were justified.

6.1.3 Work Plan/Agreement Compliance

Overall agreement compliance: The demonstration was based on an agreement form that is well balancedas a partnership agreement between two cooperating parties and contains a clear allocation of work andfinancial responsibilities. The latter is essentially as originally proposed by EDL where the Office 33PMU using GEF funds supplied through UNDP would provide and pay for acquisition, characterization,packaging and shipment of test soil samples to EDL, and after the pilot testing would pay for the inputand output soil analysis scope specified to a qualified international laboratory as listed in Section 3 above.EDL would cover all costs of receiving test soil samples, testing in the designated pilot facility, shipmentof analytical samples to the designated international laboratory. Overall these arrangements appear tohave been fulfilled by both parties satisfactorily.

50Comparable large scale PCDD/F contaminated site experience is limited to the high cost application of a thermal

desorption/base catalytic de-halogenated (BCD) process at Spolana in the Czech Republic, the current application ofin-pile thermal desorption currently being applied at Da Nang in Vietnam by US AID and MND, and the 2004processing of 24,000 t of PCDD/F contaminated coral at Johnson Atoll related to defoliant herbicides removed fromVietnam in 192 using the TTI MCSTM enhanced thermal desorption technology.

In terms of performance of the work, the actual pilot demonstration work followed the work plan exceptthat the original intent to undertake the work in New Zealand was changed to undertaking it at anequivalent facility operated by a EDL MCD Technology licensed company partner associate company inSouth Africa (Enviroserve Waste Management). The pilot tests were conducted as specified in theagreement schedule but the delivery of the final technical report was not presented until February as aresult of delays in receiving analytical results from the Office 33 PMU contracted laboratory. The onlysignificant variation from the agreement and appended work plan was: the RPM specified for Test Run 1(medium concentration) was increased from 350 to 450 ppm, and complete heavy metals andorganic/inorganic As analysis was only done on one output sample, rather than on input and outputsamples for each test run. EDL indicated this was being pursued with the laboratory. Additionally outputsoil properties were not evaluated and no EOX analysis was done.

Work plan scope and implementation: The scope of the work plan was as appended to the PartnershipAgreement. A verbal agreement existed to use the original EOI TOR as an informational document andonly as it might be reasonably applied. The work plan is summarized in Table 6.1 below. The pilot testwork was undertaken over a two day period between November 26 and 27, 2015 on two 20 kg testsamples received from the Office 33 PMU. One was labelled 0314VN2.3 and corresponded to the“medium” PCDD/D soil concentration (28,500 ppt TEQ per the baseline analysis), and the second waslabelled 0714VN5 and corresponded to the “high PCDD/F soil concentration (68,100 per the baselineanalysis). As indicated in Table 6.1 and as defined in the Partnership Agreement, the agreed pilot testprogram consisted of six separate runs. Runs 1, 2 and 3 were on the “medium” concentration soil andRuns 4, 5 and 6 were on the “high” concentration soil, noting that subsequent input analysis byAsureQuality indicated that the medium concentration was 28,500 ppt TEQ as in the baseline analysisbut the “high” concentration was 71,700 ppt TEQ which differed from the baseline analysis by a smallamount. The following summarizes the test procedures:

The two bulk test samples were dried upon receipt to a moisture content of <1% resulting in testsample 0314VN.2 weighting 18.4 kg, and test sample 0714VN5 weighting 18.7 kg.

The test samples were sub-divided into three run test samples of 6 kg for each of the originalmedium and high test samples and sealed in clean containers prior to use.

A sampling labeling protocol as specified in the work program was adopted as follows: i) Status: U– untreated, T- Treated; and ii) Resident time: A – 15 minutes, B -30 minutes, C – 45 minutes andD – 60 minutes with samples taken at the reactor51

38g of bentonite reagent (0.6% by weight) was added to Run 2 (originally it was planned to usezeolite) to assess potential capacity to bond heavy metals and particularly As

25g of titanium dioxide reagent (0.04% by weight) was added to Run 2 based on its having apositive impact on previous trial on DDT soil remediation performance.

Quartz was added to Run 5 and not Run 6 to assess its impact in increasing process collisionfrequency and efficiency.

Prior to starting each day the reactor was heated by running 10kgs of sand at 450 rpm for 1 hour. Thesand was discharged and weighed to check that 10kgs had been removed

51A sample labelled was also taken “E” a sample taken midway through the discharge of the reactor at the end of

the test but this result was not used due to cross contamination issues.

Table 6.1: EDL - Work Plan Pilot Test Conditions

Run

No

SoilSampleLabel

SoilSampleWt (kg)

DioxinConc,Level(ppt

TEQ)

ReactorBall Wt

(kg)RPM Reagent Quartz

RunTime

SamplingInterval

(minutes)

AverageAmperage

Draw

1 0314VN6 28,500 120 450 No No

1hour 15/30/45/60 72 amps

2 0314VN6 28,500

120450 Yes* No

1hour 15/30/45/60 71.2 amps

3 0314VN6 28,500 120 450 No Yes

1hour 15/30/45/60 72 amps

4 0714VN 6 71,700 120 350 No No1

hour 15/30/45/60 71 amps

5 0714VN 6 71,700 120 450 No Yes1

hour 15/30/45/60 71 amps

6 0714VN6 71,700 120 450 No No

1hour 15/30/45/60 71 amps

*38g Bentonite, 25 g Ti2

The input and output results for all six test runs for the primary organic contaminants of interest(PCCD/F, dioxin-like PCBs, acid pesticides, and principle chlorophenols) and RE/DE calculations whererelevant are summarized in Table 6.2. The EDL report contains the expanded analytical results includinggraphical analysis of initial and changing PCDD/F and dioxin like PCB congeners.

Demonstration program costs: The EDL pilot demonstration costs were estimated to total US$250,000with the note that if integrated into an actual commercial project opportunity rather than this morecomplex process, undertaking qualification pilot demonstration work would typically cost approximatelyUS$100,00052. GEF financed costs were estimated by the PMU/UNDP to be US$60,000.

6. 2 Pilot/Laboratory Demonstration Results Evaluation

6.2.1 Achievement of clean-up targets for PCDD/F contaminated soil

PCDD/F soil concentration level(s) tested: The medium contamination runs were conducted on soilhaving an input concentration of 28,500 ppt TEQ (the same as the baseline analysis) and for the highconcentration runs on soil having 71,700 ppt TEQ (somewhat higher than the original baseline analysis).This input analysis was based on a composite sample from the original received lot and is assumed to berepresentative of the run sub-lots in each case. In terms of congener distribution the data provided inEDL’s report both input untreated analysis indicated an expected distribution with the highly predominantcongener being TCDD.

PCDD/F remediation levels achieved: As illustrated in Table 6.2, the results for the mediumconcentration soil showed that overall progressive PCDD/F reduction/destruction was occurring at thefour time intervals and achieving concentration levels below 1,000 ppt TEQ and in two runs achievedlevels below 200 ppt TEQ with the best result achieved being 110 ppt TEQ when the TiO2 reagent was

52E-mail Communication, Marcus Glucina to R. J. Cooke, February 23, 2015

used. This run also showed a more rapid rate of reduction with run (residence) time includingapproaching the 1,000 ppt TEQ level in 30 minutes rather than 45 minutes and 60 minutes required forRuns 1 and 3 respectively. The poorest but still acceptable performance was Run 3 at 731 ppt TEQ whichhad the quartz additive. The results for the high concentration soil showed that the best performance (Run6) where a concentration level below 1,000 ppt was achieved without additives. Somewhat poorerperformance that was approaching 1,000 ppt TEQ occurred with the same operating conditions but withquartz additions (Run 5), confirming a counter intuitive negative effect of this addition at least on thesesoils. Worse performance occurred with Run 5 where the RPMs were reduced, demonstrating thesensitivity of high concentration performance to this operational parameter. Overall the resultsdemonstrated that the nominal medium range of soils should be well within the capacity of the process toachieve the minimum acceptable soil quality with flexibility to go to levels below any applied in Vietnamfor any contemplated land use. For the high concentration range which generally would be a relativelyinfrequent occurrence in practice if preparatory soil mixing was employed show that the process canachieve the required level without additives and this essentially serves as a baseline qualification run. Ontop of this baseline there is flexibility for lower levels with addition of TiO2, and increased residencetime, while maintaining the higher rotational speeds. While it might be anticipated that the effectivenessof the process will taper off and flatten out at some concentration level, it is not yet evident where thatpoint is in these pilot runs at either concentration level except that it would be at a level much lower than1,000 ppt TEQ and likely 200 ppt TEQ thus the results suggest that the process is fully qualified anycontemplated soil quality level.

Results for Dioxin like PCBs – As previously noted the levels of dioxin-like PCBs are low initially but inall cases these were further reduced levels less than 1 ppt all runs except Run 4 essentially confirming thatthe process provides destruction capability down to very low levels of complex chlorinatedcontamination.

Acid herbicide/chlorophenol soil concentrations tested: The input levels of 2,4-D and 2,4,5-T (Figure6.2) are high for both the medium concentration runs (990 ppm and 2,300 ppm respectively) and highconcentration runs (2,100 ppm and 5,100 ppm respectively). 2,4-D levels also exceed the US EPA sitescreening levels (SSL)53 for residential land uses but would be acceptable for industrial and commercialland use. Chlorophenol levels and exceed the CCME soil quality guidelines for all land uses but arewithin the US EPA SSL guidelines.

Acid herbicide/chlorophenol soil concentrations achieved: The results for 2,4-D/2,4.5-T show significantreductions for the medium concentration runs with achieved concentrations down to less than 20 ppm for2,4-D and less than 30 ppm for 2,4,5-T with Run 2 achieving levels of 3 ppm or less, suggesting that as inthe case of PCCD/F the TiO2 is enhancing de-chlorination. For the high concentration runs the resultsare not as good but Run 6 reduces levels of both herbicides below 50 ppm. Again the poorest results arefor the lower rotation rate and the quartz additive has a retarding effect relative to having no additive. Forchlorophenol, the result for Runs 2 and 3, the achieved levels that would meet internationalindustrial/commercial land use standards for both principle chlorophenols. For the high concentrationmaterial Runs 5 and 6 showed similar performance for one of the chlorophenols and approached anacceptable level in the other case.

6.2.2 Measurement of Destruction (Remediation) Efficiency

PCDD/F Remediation Efficiency (RE) achieved: The principle RE of interest relates to PCDD/F as theprimary contaminate of interest and the only POP involved other than trace dioxin like PCBs. The REperformance generally tracks the soil remediation concentration levels. For medium soil contamination

53http://www.epa.gov/superfund/health/conmedia/soil/pdfs/ssg_appa-c.pdf

levels the RE’s range from 97. 4% to 99.6 all of which would generally be consider good for remediationtechnologies where it also achieved soil clean-up standards as it does in this case. In all cases RE’s of>90% were obtained after 45 minutes resident time and for Run 2 after 30min. The best result wasobtained for the Run 2 with the TiO2 and the lowest for the Run 3 with the quartz addition. For the highsoil concentration runs, the range of RE’s was from 80.5 % for the low RPM Run 4 to levels of 97.8%and 98.7 % for Runs 5 and 6 respectively with both runs achieving well over 90% after 45 minutes, againgenerally consider good remediation performance. The same trends were followed for dioxin like PCBswith remediation efficiencies being well above 95% for all runs except the low RPM Run 4. Overall, thetechnology demonstrated effective remediation capability across the range of worst case soils likely to beencountered for two complex POPs chemicals.

Acid herbicide remediation efficiency: Recognizing the potential interest in these kinds of technologiesfor application to pesticide contaminated sites generally, the REs for 2,4,-D and 2,4,5-T approached orexceed 99% for the medium PCCD/F soil concentration runs and with the exception of the low RPM runthe RE performance is in the 96 % to 98% range for 2,4-D and 98% to 99 % range for 2,4,5-T on the highPCCD/F soil concentration runs which is good remediation performance for these very high pesticide soilconcentrations and suggest potential positive prospects for chlorinated obsolete pesticide contaminatedsoil sites generally and particularly POPs contaminated sites increasing being addressed on GEF projects.

Equivalence to true destruction efficiency: It is a reasonable assumption that the REs noted above can beviewed as effective process DEs with actual destruction through de-chlorination occurring and beingsustained with time. In effect the addition of residence tine should allow the process to achieve that lowersoil concentrations and higher RE or process DEs are achievable. It is not yet evident where the limit ofthe technology’s effectiveness is. However, projections of the levels with increased residence timesuggest that process DEs would be well above 99%. While, the technology cannot be considered toqualify as a POPs destruction technology meeting the 99.99% DE level required in Convention and GEFguidance at this point, the results suggest that with refinement this offers a high potential to be achievablewith some refinement.

6.2.3 Energy and Resource Requirements

Energy requirement data provided: The energy consumption data provided was the limited to theaverage power draw for each run in amperes as indicated in Table 6.1. The only observation that can bemade was that this was constant for all runs suggesting that power consumption at least for the destructionprocess is generally independent of operating conditions although one would expect as it was scaled upthere would be variation of power requirements with run time, rotational speed, ball loading conditionswhich appears to be the key factors in adjusting the destruction process to various concentration levels.The current data could be useful in extrapolating estimates to a full scale commercial configuration asdiscussed below with the qualification that power demand for an overall plant also includes a significantdemand from the dryer.

Chemical consumable data provided: The nominal reagent additions of bentonite and TiO2 are foot notedin Table 6.1. It would appear that the only major one that could potentially be used for future full scaleapplication might be selective use of TiO2 with the volumes being relatively modest (0.4% of soilvolume). As discussed below in relation to heavy metals, a future prospect of using zeolite to bind upmetals, particularly arsenic is a prospective area of further investigation.

Table 6.2: EDL- Summary of Pilot Test Results for “Medium” and “High” Concentration Test Samples – Primary Organic

Contaminants (PCDD/F, Dioxin-Like PCBs. Acid Herbicides and Principle Chlorophenols)

Substance UntreatedRun 1 Run 2 Run 3

A-15 B-30 C-45 D-60 A-15 B-30 C-45 D-60 A-15 B-30 C-45 D-60

PCDD/F - ng/kg (ppt)WHO TEQ 28,500 8,350 5,300 1,200 172 6,050 1,180 72 110 9,660 6,060 2.390 731RE/DE (%) 70.7 81.4 95.7 99.4 77.8 95.7 99.8 99.6 66.1 78.7 91.6 97.4

Dioxin-Like PCBs –ng/kg (ppt)Total TEQ 15.9 5.45 5.85 1.07 0.557 5.83 0.809 0.79 0.37 5.35 5.55 2.24 0.310TE/DE (%) 65.7 63.2 93.3 96.5 63.3 94.9 95.0 97.7 66.3 65.1 85.9 98.1

Acid Herbicides – mg/kg (ppm)2,4-D 990 450 220 33 8 88 11 1.5 2.3 630 220 57 202,4-D RE/DE (%) 54.5 77.8 96.7 99.19 91,1 98.9 99.8 99.8 36.4 77.8 94.2 98.02,4,5-T 2,300 930 400 53 13 94 11 1.6 3 1,500 380 88 302,4,5-T RE/DE (%) 59.6 82.6 97.6 99.3 95.9 99.5 99.9 99.9 34.8 83.5 96.2 98.7

Principle Chlorophenols –mg/kg (ppm)2,4.2,5-DiChlorophanol 15 37 120 140 110 36 8.6 1.4 0.84 35 40 17 4.62,4.5-Trichlorophenol 53 110 70 9.4 1.2 44 7 1.3 1 99 73 20 4.5

Substance UntreatedRun 4 Run 5 Run 6

A-15 B-30 C-45 D-60 A-15 B-30 C-45 D-60 A-15 B-30 C-45 D-60PCDD/F - ng/kg (ppt)

WHO TEQ 71,700 34,100 30,300 22,300 14,000 26,700 18,100 6,510 1,580 26,300 15,500 5,200 914RE/DE (%) 52.4 57.7 68.9 80.5 62.8 74.8 90.9 97.8 63.3 78.4 92.8 98.7

Dioxin-Like PCBs –ng/kg (ppt)Total TEQ 18.2 10.4 8.33 7.65 7.14 7.12 7.08 3.75 0.53 8.45 7.72 2.16 0.467TE/DE (%) 42.9 54.2 57.9 60.8 60.9 60.7 79.4 97.1 53.6 57.6 88.1 97.4

Acid Herbicides – mg/kg (ppm)2,4-D 2,100 1,700 1,400 1,000 410 1,300 680 200 86 1,300 1,000 110 272,4-D RE/DE (%) 19.0 33.3 62.4 80.5 38.1 67.6 90.5 95.9 38.1 62.4 94.8 98.72,4,5-T 5,100 3,900 2,900 2,000 720 3,000 1,400 310 130 2,700 1,600 130 412,4,5-T RE/DE (%) 23.5 43.1 60.8 85.9 41.2 72.5 93.9 97.5 47.1 68.6 97.5 99.2

Principle Chlorophenols –mg/kg (ppm)2,4/2,5-DiChlorophanol 31 110 120 140 110 36 8.6 1.4 0.84 35 40 17 4.62,4.5-Trichlorophenol 110 300 370 380 180 330 270 110 20 300 240 74 14

64

6.2.4 Process Features

The EDL final report, directly or by reference to more elaborated materials provided in its January 2013report on its 2012 demonstration and training materials for Vietnamese professionals delivered as part ofthat work, provides a reasonably complete and well referenced process description highlighting thechemical processes and reactions, applicable theoretical equations and discussion of process by-productlevel at level allowing an assessment of the scientific basis for it, but perhaps not at a level of detail for in-depth study or parallel development, all recognizing its proprietary nature. At a pilot scale level therequested mass balance aspect obviously cannot be addressed in this particular demonstration beyond theprovided data on material in and out. Where this TOR requirement has more relevance is in theevaluation of a full scale case and would potentially involve a discussion on what might be proprietary.

With respect to the requirement for consideration of harmful by-product formation in theremediation/destruction process, again the pilot scale demonstration offers little information in this areabeyond what might be speculated on. Theoretically the de-chlorination process should completely breakdown the chlorine bonds and not form such by-products. However, EDL’s analysis does note that in thecourse of this process while it occurs during the resident period of the soil in the reactor, there is a changein the relative congener mix early in the reaction period with an increase in TCDF as TCDD istransformed followed by its transformation/destruction. Similarly there is an observed initial increase insemi-volatile organics, namely 2,4,2,5 dichlorobenzene and 2,4,5 trichlorobenzene early in the residentperiod with reductions in these contaminates then occurring. This phenomenon is also attributed directlyto the breakdown of dioxins in the soil samples.

6.2.5 Effect of Other Contaminants

Effect on Arsenic concentration: No detailed assessment of the impact of the MCD process on arseniclevels was undertaken with the analysis limited to a single run upon completion (Run 2) which showedthat as anticipated there was no substantive difference in total recoverable As in the soil between thebaseline (20 mg/kg) and the treated medium PCDD/F contaminated soil (17 mg/kg). No input andoutput analysis was done respecting organic/inorganic As content to assess the potential impact on theform of As and relative toxicity although EDL indicated this was being pursued and will be supplied ifand when available. While EDL indicates that in principle its process is not intended to deal specificallywith As and expects the toxicity of this element will not be impacted by the MCD process itself, thepossibility of investigating inclusion of additives that may serve to bind As and prevent its release isdiscussed. The use of bentonite in this application appears to have had minimal effect although perhapsthis would have required more comprehensive analysis and a leachate test. The proposal in the technicalreport to utilize zeolite as originally intended in this work should be pursued in future pilot work basedon the potential for it having suitable binding properties. It is recommended that this be pursued for Asand other secondary heavy metals, perhaps with a more comprehensive analytical program includingleachate testing.

Effect on other heavy metals: Table 6.3 above shows the baseline and output analysis for the othersecondary heavy metals. In general these are unaffected by the MCD process except for the unexplainedresults that copper increased between the baseline and the output sample. Follow up of this result usingthe actual input material for this Run might be considered although this is generally of minor interestrelative to the main purpose of this work.

65

Table 6.3: EDL - Comparison of Baseline Heavy Metals Analysis (Sample 0314VN2.3) and OutputAnalysis for Run 2

Secondary Heavy Metal Baseline AnalysisSample 0314VN2.3

(mg/kg)

Output Analysis Run 2After60 min (Sample2TD)

(mg/kg)Total recoverable Arsenic 20 17

Total recoverable Cadmium 5.1 4.9

Total recoverable Copper 40 116

Total recoverable Lead 107 108

Total recoverable Zinc 260 270

6.2.6 Other Unexpected/Unpredicted Impacts of the Technology

No unexpected or unpredicted impacts are identified from the work pilot demonstration work. Howeveras discussed in the reporting and independent evaluation of the 2012 demonstration work there are anumber of environmental release issues that require improved emission control measures in a full scalecommercial configuration. Directly related to the destruction process, there is potential for fugitiveparticulate and VOC release (as well as an odour impact) associated with the discharge of output treatedsoil. In the pre-process stage of a full scale commercial operation there also needs to measures to captureand treat particular and VOC in soil preparation and handling operations and ensuring that a robust airpollution control (APC) system operates for gasses vented at the dryer exit. These points are furtheraddressed in the evaluation of the projected full scale configuration below.

6.2.7 Soil Texture/Content after Treatment

No specific analysis was undertaken of soil properties before and after treatment although it can bepresumed that the input soil properties are as summarized in Table 3.3. An assessment of soil physicalproperties was undertaken in the 2012 demonstration work as reported in the January 2013 EDL reportand independent evaluation report. This demonstration does not add anything to the earlier work.

6.3 Projected Full Scale Commercial Application Evaluation

EDL’s final report addresses the linkage between the current demonstration work and a projected fullscale configuration that they are prepared to offer commercially. This is done in a dedicated section intheir technical report and is further addressed in appended material including a schematic and byreference to the elaborated description of a proposed two train 10- reactor plant offered in the January2013 report on the 2012 demonstration. They also indicate that the conceptual proposal for this plantcontained in the January 2013 report is explicitly re-confirmed in the conclusions of the current report.As an overall evaluation point under this heading this is essentially in compliance with a specificrequirement contained in their Partnership Agreement with the Office 33 PMU. The following assessmentis based on this material.

6.3.1 Projected Full Scale Commercial Configuration Assessment

Estimated capacity availability: The estimated capacity of a two train ten reactor configuration MCDplant (5 reactors per train) operated in series is estimated to be 8 t/hr/ per train or 16 t/hr. This estimateapplies to using a 15 minute residence time that achieved acceptable soil concentration levels in the 2012

66

work for soils in what is considered the low concentration range (15,000 ppt TEQ), althoughconcentrations somewhat above this level could likely be similarly handled with the higher rotational ratedemonstrated in the current work. In effect this capacity can be conservatively extrapolated to an annualcapacity of over 50,000 t/year (operating 12 hrs/day 300 days/year). This would be applicable to the largemajority of soil likely to be encountered, particularly if a pre-preparation soil mixing step was included inthe plant scope. The experience during this demonstration associated with even finding significantquantities of soil above the low concentration level supports this as does the accumulating bank of siteassessment of single point analytical data. The results of the demonstration clearly also show the impactof residence time for the two higher concentration levels demonstrated suggesting that roughlyproportional capacity reductions would occur with increased resident time. For the medium soilconcentration material tested (approximately 30,000 ppt TEQ) a high probability of achieving less than1,000 ppt TEQ if residence time were tripled hence roughly a capacity of 5.3 t/hr. For the highconcentration soil (70,000 ppt) this would be 4 t/hr. These capacities would also be influenced byrotation speed and potentially by optimized additive additions such as TiO2 which appears to offer someadvantages but needs to be further evaluated on a range of soil concentrations and additive volumes.Overall the projected full scale configuration should offer an attractive capacity for a large scaleremediation project on sites such as Bien Hoa or Phu Cat. It also potentially offers the flexibility tohandle special cases of higher concentration material hot spots identified at the level of detailed siteassessment required for a large scale remediation project as well as dealing with the already stockpiledand contained (in landfills or temporary containment structures) at Bien Hoa in the Z1 and Pacer Ivyareas. This would include the potential for processing the extreme concentration material segregated inbarrels in the Z1 landfill if blended back as was done to manufacture the high concentration soilsprocessed in this demonstration. This could provide an alternative to high temperature incineration whichis likely the only current alternative available for this material.

Proposed advance material preparation requirements: The projected full scale configuration proposed inthe January 2013 report and adopted by reference here includes preparation measures involving crushingof oversize material to a relatively fine input level (which enhances both drying and reactor processingefficiency by increasing the surface area of input material). It does not explicitly adopt a preparation stepbetween excavation and the plant involving mixing or homogenizing material. This was stronglyrecommended in the February 2013 evaluation report to minimize the apparent very inhomogeneousdistribution of PCDD/F concentration that is characteristic of these sites as they now exist. However, thecurrent report acknowledges this potential requirement without elaboration. From an evaluationperspective it is strongly recommended that this material preparation step be included, recognizing thatthe positive demonstration performance is effectively only valid for material with a relatively uniformconcentration distribution. In making this recommendation it is noted that the same conclusion applies toall remediation technologies if consistent predictable remediation levels are to be achieved.

Proposed pre-treatment requirements: In addition to the material preparation measures noted above, thefull scale configuration also includes a high capacity dryer which is critical to meeting the moisturecontent limits for efficient operation of the MCD process. This is covered in the January 2013 report andthe only evaluation comment would be the need to scale its capacity with that of the MCD reactor trainwith sufficient flexibility to deal with a range of moisture content conditions, although the introduction ofa mixing soil preparation stage may also include the inherent advantage of a preliminary air drying stage,thus increasing the dryer flexibility.

Proposed emission control requirements: The full scale configuration provides for a primary APC systemfor the dryer exhaust that as a minimum a cyclone, bag filter and GAC. This configuration wasdemonstrated in the 2012 demonstration. As noted in the February 2013 independent evaluation reportthe full scale configuration needs to ensure that this is a robust system essentially providing for BAT/BEPair emission performance as defined by the SC and in the various previously referenced international

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guidance documents, particularly for PCDD/F and particulate. One implication of the currentdemonstration work on the higher concentration soils is that the potential for PCDD/F emissions at thispoint in the process would be more critical. Therefore, an overall recommendation of this evaluation isthat any full scale commercial plant undergo strict qualification stack testing to verify internationallyaccepted fine particulate and PCDD/F emission levels, something that generally the technology has alimited data base for at this point. While not practical to address in the pilot demonstrations, the othermajor emission control requirement applicable to the full scale configuration is addressing fugitiveemissions from the various materials handling and material preparation activities. This would involverelatively simple conventional fume capture, dust control and indoor air management infrastructureapplied to these operations and capture of contaminants for treatment preferably in a closed systemallowing inclusion in the process. The January 2013 report addresses this generally but an assessment ofthe final design and its performance would be required for the full scale plant configuration as part ofproof of performance testing undertaken as part of permitting of a full scale commercial unit.

Proposed post treatment requirement: The same requirement above exists for the material released fromthe MCD process respecting VOC and particulate release. The full scale proposal provides for particulatesuppression by wetting and generally contemplates the kind of fume and particulate capture noted above.Again this requires performance demonstration on the full scale plant configuration as part of proof ofperformance testing undertaken as part of permitting of a full scale commercial unit.

Proposed supporting infrastructure requirements: General infrastructure requirements are described inthe January 2013 report in terms of housing structure requirements s and material handling infrastructure.Overall none of this is unusual or raises any specific issues from an evaluation perspective.

6.3.2 Site Clean-Up Targets Performance for PCCD/F and other significant organic contaminates

Projected achievable PCDD/F soil concentration levels relative to compliance levels: Given the scalingof the pilot reactor as equivalent to each of the reactors in the projected full scale configuration and thecumulative process residence time obtained as soil moves through the process should allow for theachievement of output soil concentration performance equal or potentially better than that achieved in thepilot demonstration would be expected. A high confidence would exist in achieving remediated soilconcentrations of 1,000 ppt and quite likely to less than 200 ppt TEQ on soils up to 30,000 ppt whichwould effectively cover the very large majority of bulk remediation requirements envisioned to any soilquality standard that might be contemplated. Likewise a reasonable expectation exists for achieving the1,000 ppt TEQ level as such cases are encountered periodically for higher concentration soils up to70,000 ppt TEQ and potentially higher, noting that this will entail providing the flexibility to adjustoperating parameters such as resident time, rotational speed and potentially elective additive additions.As stated above with respect to the demonstration results, any reasonable projection of increasedresidence time would suggest achievement of the 1,000 ppt and likely much lower levels even under theworse concentration conditions. Overall validation of these conclusions requires a process of rapidscreening of output levels (as discussed below) and flexibility to reintroduce material back into theprocess for further treatment as was discussed and contemplated in the reporting and evaluation of the2012 demonstration. The above conclusion is qualified by the need for trial demonstration on the fullscale plant on start-up, a qualification that obviously would apply to any technology under normalcompetent commercial practice.

Projected achievable herbicide/chlorophenol soil concentration levels relative to compliance level: Theability to reduce concentration levels of other organic contaminants of interest in a full scale configurationgenerally tracks what is described above for PCDD/F. It can be concluded that the levels of acidherbicides and chlorophenols would be reduced to levels below internationally referenced contaminatedsites soil screening levels noted above although in fact in some cases these were below this level initially.

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In terms of international soil quality standards where these exist, reductions are to less than standards forindustrial and commercial land use but perhaps not necessarily for much more conservative residentialand agricultural land use. As a comment on the fate of the two primary acid herbicides, these aregenerally considered to have a relatively short (measured in days) life in soil before degrading, whichmakes their continued presence in these soils after such a long time unexplained. One theory for this isthat they are bound up with the PCCD/F by-product contamination in localized pockets of what is generalhighly disturbed inhomogeneous soil. This being the case, once the PCDD/F is removed the expectedrapid natural degradation will likely occur, something that is facilitated by the MCD process through itscharacteristic of reducing soil particle size to a low level.

Potential for achievement of lower soil concentrations: This aspect has generally been addressed underthe two headings immediately above. Based on the demonstration work the MCD process, there is noindication that there is a limit to what level is achievable as residence time increases even at the lowoutput concentration levels achieved and, as noted, the process has a number of prospective areas tofurther investigate to optimize and improve performance, although none would be a pre-condition toproceeding with full scale commercial qualification for this site remediation application.

6.3.3 Remediation and Destruction Efficiency Performance

Projected achievable RE: Based on the above extrapolation of demonstration performance to a full scaleconfiguration, the remediation efficiencies (REs) that were achieved in the pilot demonstration should bereadily achievable. For soil concentrations in the low through medium range (up to 30,000 ppt TEQ),REs at or above 99% should be obtained which would generally be considered a good remediation levelfor a commercial remediation technology. At higher concentrations REs approaching this level but wellabove 95% could reasonably be expected and could be readily projected to higher levels with increasedresidence times.

Projected achievable DE/DRE: As previously discussed in Section 3, the demonstration as required inthe reference TOR for the demonstration work in fact could not practically address the demonstration oftrue DE or DRE performance on a pilot scale of this type. This requires a full scale demonstrationinclusive of all the planned front end and back end components to fully account for the releasespotentially involved and their environmentally sound management. All it is capable of doing isdemonstrating a process DE which in the case of the MCD demonstration would be equivalent to the REwith that closed process. For this reason the following discussion of DE/DRE is by necessity speculativebut should highlight issues that would be applied when using these parameters in assessing or specifyingrequirements for a technology. Overall it would be expected that the true DE/DRE would be somewhatless than the RE or process DE levels achieved in the case of PCDD/F and chlorophenols but to thedegree it is relevant would likely be close to the same for the two acid herbicides considered. In the caseof PCDD/F and chlorophenols, these contaminants have potential for release during soil preparation,drying and at the point of release of the treated soil from the process itself. PCCD/F which is of primaryinterest this would be as a direct air release from the dryer stack after APC treatment, in the treatmentresiduals in the APC system (bag house dust and GAC material) and as contaminated particulate releasedas fugitive emission during soil preparation and pre-processing. At this point except to the degree theAPC residuals and stack emissions, and confirmation of ambient air quality dust levels were monitoredduring the 2012 demonstration work, these aspects of technology environmental performance have notbeen evaluated and translated into DE/DRE estimates. This would be something that could only be doneat start-up trial confirmatory performance assessment of a full scale commercial application. The onlypoint that can be made respecting projected performance are that the inclusion of adequate particulate andair capture and management as recommended above as well as a robust APC system inclusive of processreturn provisions in the full scale configuration design should effectively minimize the effect on DE/DREfrom fugitive emission contaminants . In the case of solid APC residuals these are likewise returned to

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the process for contaminant destruction. In particular the treatment of PCDD/F contaminated GACmaterials by the MCD process has been has been successfully demonstrated by EDL on a pilot scale foranother application, achieving DEs in excess of 90%54. In summary, it is likely that DE levelsapproaching those reflected in the RE/process DE are achievable.

Compliance DE/DRE potential relative to international standards: It can be concluded that the MCDprocess is a true destruction process in the context of providing destruction or irreversible transformationof PCCD/F. However, at this point in this application it would not fully qualify as a POPs destructiontechnology in terms of meeting true DE or DRE levels for PCDD/F and other organics as set out ininternational guidance for organic hazardous waste destruction which in the case of POPs relates tocompliance with Article 6 of the Stockholm Convention. Having said that there would certainly bepotential with refinements to increase destruction efficiency to a point where it could serve as a means ofPOPs waste destruction, something that would have to also consider competitiveness with widelyavailable commercial options.

6.3.4 General Environmental Performance

Projected VOC management performance: The evaluation observations above under in relation to theneed for VOC capture at release points apply, specifically though fume capture and routing either into thedestruction process or dryer/associated APC system. Application of readily available BAT/BETtechniques should provide acceptable performance.

Projected particulate management performance: The evaluation observations above in relation to theneed for VOC capture at release points apply, specifically though dust capture and routing either into thedestruction process and also applying overall indoor air quality management techniques. Application ofreadily available BAT/BET techniques should provide acceptable performance.

Projected As/heavy metals management performance: There is not likely any impact on total recoverablemetals or As levels in a projected full scale configuration as envisioned based on limited data available.Some potential exist for the addition of binding additives but this requires further verification as notedabove.

6.3.5 Performance Monitoring Requirements

Input soil characterization: Detailed site soil contamination analytical site assessment data would berequired prior to soil excavation and as a soil monitoring/screening QA/QC analysis protocol should beapplied at the soil preparation stage to address variation in soil concentration and its distribution withinexcavated lots.

Operational OA/OC monitoring: The operation of a full scale MCD plant as projected should makeprovision for an on-site rapid turn-around analytical capability (or offsite capability if suitable turnaroundwas offered) for verifying concentrations achieved in output soils. This was envisioned in the January2013 EDL report and discussed in the February 2013 independent report. It involved accumulation oftreated soil in roll off containers that would be held, sampled and then sent for final disposition ifaccepted or reintroduced back into process chain for retreatment. For PCDD/F analysis which wouldprimarily apply as an acceptance base, the likely best option would be a portable low resolution GC/MSnot widely used for screening on site remediation projects with period high resolution QC/QCverification. The same capability would also serve for assessment of other contaminants and potentiallysome environmental monitoring requirements if air sampling and analysis capability were provided for.

54 EDL - Private Communication, February 2015

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Environmental monitoring: Given the potential for fugitive particulate and VOC emissions, point sourceand ambient monitoring of the plant site and indoor air quality should be provided for. Periodic PCDD/F,particulate and VOC release from the dryer stack should also be provided for, likely undertaken by anexternal sampling and analytical contractor with high resolution capability.

6.3.6 Treated Soil and Residual Disposition Issues

Treated soil disposition actions and restrictions: While not assessed as part of the demonstration work,the fine grained nature of the output soil as well as the limited organic content would limit its direct usefulapplication in agriculture although EDL indicated that positive experience has been seen with being ableto obtain cover vegetation after spreading on cleaned up sites. There may also be potential to use thematerial in selected building material applications. However in the volumes that would be generated overa short period of time in a full scale commercial application such as contemplated as being done on theairbase sites, the most probable disposition would be return to its excavated locations and then cover withhigh organic top soil material to limit particulate distribution and to foster re-vegetation. In terms offuture land use this would largely be dictated by the PCDD/F acceptance level (commercial/industrial for1,000 ppt TEQ) and any land use restrictions imposed by other secondary contaminants. Overall, giventhe history of these sites it would likely be appropriate to restrict land use to commercial/ industrial landuses in any event.

Treatment residual disposition considerations: The primary treatment residuals generated by the fullscale process are bag house dust and saturated GAC. Both should be readily managed by re-introductioninto the process for organic contaminant destruction.

6.3.7 Operational Applicability Assessment

Access/support infrastructure requirements: Infrastructure details including foot print requirements andlayout would be developed on a site specific basis. Access requirements would involve capacity for truckscarrying standard sea shipping containers, laydown and lifting capacity, a covered hard stand surface withmoderate load bearing capacity, basic changing, amenity and office space, sufficient flexibility to maindesignated clean and contaminated areas with transition zones for PPE application. Based on previousexperience at Bien Hoa this should all be available or readily constructed for temporary use. Normalprovisions related to site access control zoned restrictions respecting contaminated and clean work areasand areas would apply.

Energy supply: This was extensively discussed in the relation to the 2012 work and EDL’s January 2013report. It was also a point of discussion in terms of the estimated requirements with Vietnamese expertsand UNDP's technical adviser. Without attempting to add to that discussion, it is should be understoodthat a reliable uninterruptable power supply is important to the efficient and effective operation of theMCD process. As seen from the 2012 experience, the utility grid supply at Bien Hoa is not particularlyreliable, and was expensive when all charges imposed were factored in. Of particular concern was thesignificant impact on the demonstration through frequent shut downs and the resulting transients that thiscaused in technical and potentially environmental performance. For that reason, it would be stronglyrecommended that self-contained power generation be provided as part of a full scale plant package withthe cost factored (internalized) into the commercial service cost. This basically removes this as anoperational constraint and a concern in consideration of the technology.

Other utility availability: The only other utility likely required is domestic water which should be readilyavailable from local supply or truck tanker delivery.

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Process consumables availability: In a base case no chemical additives are involved although TiO2 mightbe used. It is assumed that would be available locally or by import in the relatively small quantitiesinvolved.

Operational complexity: Overall, the technology would be considered of moderate complexityrecognizing the 2012 experience. It basically requires a strong “know how” element in its set up andoperation, the latter which as demonstrated was essentially a manual operation from a materials handlingand controls perspective. A fully sized commercial plant needs to address this in terms of more efficientautomated materials handling and particularly in terms of automation of the control system inclusive onoperational and performance variable monitoring. The proposed full scale configuration acknowledgesthis and makes such provisions. This would reduce the nominal complexity as well increase theoperational as reliability and productivity. It would require skilled (likely international) supervision andtechnical support particularly during set up and commissioning. However EDL did demonstrate that withappropriate training national technical experts could quite competently be part of the operation andsupervision and operation could ultimately be entirely nationally manned and supervised for a majorproject. Therefore complexity in the context of suitability for national operation would not be an issue,particularly given the high quality and work ethic of young Vietnamese technical professionals. As afinal observation, this type of operation would have strict occupational health and safety requirement soan element that would need some priority would be training and implementation of strict protocols in thisarea.

National human resource availability/training feasibility: As covered above in the context of complexity,the technical expertise and labour capability for normal operation including long term supervision shouldbe readily available in Vietnam. External service providers for monitoring, laboratory support etc. isreadily available through established research institutions and commercial service providers, many of whoare familiar with the issue already.

International technical support requirement: An initial international technical support requirement wouldbe required at start up and commissioning and likely at least periodically during operation.

Long term operation and monitoring requirements: Long term monitoring after completion andcertification of the remediated site would not likely be required after completion for the plant operationdirectly.

6.3.8 Projected Cost

Indicative unit cost for fee for service operation: The quoted indicative cost on a chargeable $/t basispresented in the January 2013 report was US$380/t inclusive of self-contained power supply. This ispresumed to be applicable to concentrations <30,000 ppt TEQ. Therefore it would be anticipated that unitcost increases would apply with to higher concentration levels but likely in rough proportion to theinverse relationship between resident time and productivity. This would suggest that even for the highestconcentrations like encountered practically and even treating extreme material such as that segregated inthe Bien Hoa Z1 landfill or contaminated GAC material from other operations, the technology would bemore than competitive with current market prices globally for high temperature incineration or disposal ina qualified cement kiln in Vietnam.

Indicative capital cost for equipment supply and international technical support for implementation:The January 2013 report indicates that the purchase of such a plant would involve an indicative capitalinvestment of US$5.0 million exclusive of slab, housing and power supply.

6.3.9 Technology Acquisition/Transfer Potential

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While no specific undertakings have been documented in this area in the current work, EDL haspreviously been open about its interest in arrangements (joint ventures, licensing, equipment supply, andtechnical support services) involving transfer to a Vietnamese entity bringing capital and operationexperience. This may involve licensing of any proprietary aspects and royalty arrangements. EDL hasconfirmed that this interest is still active.

6.3.10 Further scaling-up, demonstration and commercialization

The technology is considered fully commercialized and does not require any further piloting ordemonstration at that scale except as might be undertaken electively to further optimize performance orevaluate the use of additives. The company has a readily available capacity to do so. As such it should beconsidered fully technically qualified for tendering on any current or future site remediation opportunitiesincluding what may be contemplated at Bien Hoa. The only qualification that would be applied (andwould be to any technology in this situation) is the demonstration of required technical and environmentalperformance at start-up.

6.4 Evaluation Conclusions and Recommendations

By way of overall conclusions and recommendations for this evaluation, the following would apply:

The EDL MCD technology, as demonstrated, met and exceeded the substantive technicalperformance requirement of reducing the PCDD/F concentration of the test sample soil below therequired minimum level of 1,000 ppt TEQ and in most cases to a level below 200 ppt TEQ whenapplied to what is generally categorized as a “medium” concentration range of contaminated soils ofinterest (30,000 ppt TEQ), a result that confirms the results and conclusion from the 2012 large scaledemonstration program.

The technology as demonstrated also generally met or closely approached the required minimumlevel of 1,000 ppt TEQ for the “high” soil concentration (70,000 ppt TEQ) with a high probabilitythat small variations in operating parameters, residence time and additives would ensure fullachievement of this threshold level where applied to what is likely the extreme bulk soil concentrationthat would be encountered.

The achieved remediation efficiencies (REs) for input PCCD/F concentrations up to 30,000 ppt TEQwould be anticipated to approach or exceed 99% and for the high concentrations an RE in the rangeof 98% is a reasonable expectation, both being considered good performance for remediationtechnologies generally

The demonstration results suggest that the technology will remediate all considered concentrationlevels down below international contaminated site screening and soil quality standard levels for otherorganic contaminants of interest (acid herbicides and chlorophenols) at least to levels required forcommercial and industrial land use.

The demonstrations indicate that the technology has no effect, positive or negative on arsenic orheavy metals levels noting that after remediation the soils may theoretically not be in compliance withprevailing soil quality standards, therefore could be subject to land use restrictions, likely limiting itto uses involving some containment and at best commercial and industrial future development.

The above pilot demonstration results would generally track to the same anticipated remediationperformance being anticipated on the projected full scale configuration of the technology that wouldoffer a basic bulk soil capacity of 8 t/hr.

The main issues noted in relation to the full scale projected technology are the same as thoughhighlighted in the February 2013 evaluation report, namely provision of more comprehensive inputsoil preparation (including homogenization), capture of point source fugitive emissions (particulateand VOCs) during materials handling and preparation, a robust APC system, control systemautomation, on-site analytical QA/QC capability for technical performance monitoring, operational

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environmental monitoring provisions (dryer stack emissions, indoor air quality, external ambient airquality),

Operationally the technology is moderately complex but well within national technical capacity andhuman resource availability.

The service costs applicable to a commercial full scale plant operated on a commercial basis areestimated to be US$380/t which should represent a more than competitive rate on both the global andnational market.

It would also be a technology that should be amenable to acquisition by or transfer to a Vietnameseentity for long term operation through conventional and transparent commercial businessarrangements, something that EDL indicates an interest in pursuing.

In summary EDL’s MCD technology is considered technically qualified for remediation applicationson the large majority of PCDD/F contaminated soil likely to be encounter for even the mostrestrictive land use and as such should be considered in any commercial opportunities that ariseincluding for pending remediation work at Bien Hoa without further demonstration of this type, andlikewise would be candidate for POPs contaminated sites being addressed by the GEF globally.

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9. Overall Conclusions and Recommendations

The following summarizes the principle overall conclusions and recommendations that flow from thisindependent evaluation:

Successful technology demonstrations completed: The GEF financed, UNDP supervised and Office33 managed terminal technology demonstration program was generally successful in demonstratingthree non-combustion technologies that have potential for application in Vietnam on PCCD/F andother POPs contaminated sites, as well as globally for POPs and other chemicals contaminated sitesof interest to the GEF in its mandate to seek global environmental benefit. As such it provides anexcellent initiative to close this GEF project on. The only major constraint on it being fullysuccessful was that the test programs for two of the technology demonstrations (HPC Envirotec andTTI) were truncated due to the time constraints imposed by the termination of the GEF project andboth could have potentially achieved more definitive results with more time and in one case beingsupplied with a broader range of test soil concentrations. However, in both cases, follow uparrangements are being pursued to address this deficiency.

Two fully commercial, cost effective remediation technologies are demonstrated for use in Vietnamon pending large scale applications: The results indicate that two of the demonstrated technologies(EDL MCDTM and TTI MCSTM) are essentially technically and commercially qualified to undertakefull scale remediation projects in Vietnam on a commercial basis and should be considered as costeffective, environmentally sound candidates for near and long term commercial opportunities for thepending major “hot spot” remediation projects. The one qualification applicable to both is that theydemonstrate remediation and environmental performance during start-up “proof of performance”testing on a full scale commercial unit at the start of such a project, something that any prudentcommercial contracting of such technologies would do in any event.

Extended demonstration of the MCSTM on higher concentrations to be pursued: The additionalqualifications for the TTI MCSTM technology is that i) it would be beneficial to undertakedemonstration of the expected good remediation performance on higher concentration materialswhich TTI has undertaken to do on test samples prepared with GEF funding as requested from Office33, and which UNDP has agreed to facilitate the supply of through; and ii) that further parallel workinclude determination of the fate of contaminants extracted from the soil and possible impacts onarsenic form and concentration.

Prospective bio-chemical treatment strategies recommended for field pilot testing: The HPC-Envirotec demonstration work is recognized as being at a different stage of development relative tothe other two technologies with the next step being moving from a laboratory treatability testing stageof various bio-chemical treatment strategies to undertaking a longer term field pilot program on whatare most prospective options. The feasibility of doing this should be pursued, potentially usingbilateral funding and/or perhaps in association with parallel field pilot study work involving similartechniques in another GEF-4 project on POPs pesticides, and a recently initiated MND research anddevelopment initiative at Bien Hoa.

Successful management of demonstration test samples reflects positive application of lessonslearned from previous demonstration work: The program also demonstrated the positive applicationof lessons learned from the previous demonstration work in relation to the soil sampling andcharacterization procedures to be applied to the acquisition of test sample materials. The process ofidentification, excavation, screening and assembling consistent test soil samples in three target ranges

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of PCDD/F concentrations undertaken by national experts was well managed and successful. As suchthis should serve to inform the development of practices and procedures used in future demonstrationprograms.

Results expand the understanding of the nature and distribution of contamination and need for apreparatory stage involving homogenization of as-excavated soil: Based on the above experience,additional knowledge respecting the nature of soil contamination, its distribution and overall localizednature of contamination extremes on the Bien Hoa site was obtained which further underlines thevariability of as excavated soils and the potential value in improving the level and predictability oftechnology performance as a general principle through a preparation stage involving mixing andhomogenization.

Overall the subject sites are considered generally subject to widespread industrial contamination andlikely inherently limited to industrial/commercial land use: As a general observation, while thedemonstration program shows that at least two fully commercial technologies are available toremediate PCDD/F contaminated soils to any land use acceptance criteria that might be practicallysought in terms of organic contaminants, the inherent nature the hot spot sites is that they are complexhighly disturbed industrial sites containing a variety of other secondary contaminants that should limitfuture land use to industrial/commercial land use in any event on the main areas of former defoliantmanagement.

All demonstrated technologies are suitable for commercial application in Vietnam under nationaldirection: With respect to the legitimate priority expressed by national stakeholders respectingnational participation in the commercial application of remediation technologies, all threedemonstrated technologies can be readily applied in Vietnam using national expertise and resourcesafter a period of training and with some initial international technical support, and would also betechnologies that should be amenable to commercial arrangements supporting their acquisition by ortransfer to qualified Vietnamese entities for long term operation,

Beneficial synergies exist between the demonstrated technologies and opportunities to exploit themshould be pursued: The current evaluation is not intended to be considered comparative but as ageneral overarching observation, there are a number of areas of potential synergy between thetechnologies/techniques demonstrated such that their integrated application in the near and longerterm would be beneficial, particularly if established and sustained in the country on a commercialbasis. There is an immediate place for direct invasive interventions in major hot spots and landrequiring rapid remediation for near term redevelopment, a role that either or both the MCDTM andMCSTM technologies could fill This includes working cooperatively given the large volume projectsand short time frames that could be financed in the near term particularly at Bien Hoa. This could alsoinvolve distributions of responsibilities depending on the concentration levels involved andpotentially management of contaminated residuals, particularly contaminated GAC and material ofextremely high PCDD/F concentration. The role of bio-chemical treatment strategies such asproposed by HPC Envirotec has a longer term application characteristic and would potentially have aplace on the periphery of the large heavily contaminated sites and on potentially numerous smallermore widely distributed PCDD/F contaminated sites that are and will continue to be identified aroundthe country.

The demonstration results identify highly prospective technologies potentially highly suited to globalapplications related to POPs and general chemicals management of contaminated sites and wastes:In conclusion, the current demonstration program can be considered very successful and usefulapplication of effective adaptive management by the UNDP and Office 33 project team in utilizing

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GEF resources for both national and global benefit with the results being recommended for widedissemination through UNDP and the GEF. In that regard, a number of GEF projects underpreparation or currently initiating implementation will find the results of this work immediatelyapplicable.

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Appendix 4: List of applicable references

APPENDIX 4 - List of Applicable References

1 REFERENCES/Oct18

The list below provides relevant references for the degradation of POPs by high energy ball milling. Further references can be provided on request.

Academic Papers

1. Birke, V., Mattik, J., & Runne, D. (2004). Mechanochemical reductive dehalogenation of hazardous polyhalogented contaminants. Journal of Materials Science, 39, 5111-5116.

2. Bellingham, T. (2005). The Mechanochemical Remediation of Persistent Organic Pollutants and Other Organic Compounds in Contaminated Soils. Auckland University of Technology PhD Thesis.

3. Cagnetta, G., Huang, J., Wang, B., Deng, S., & Yu, G. (2016). A comprehensive kinetic model for mechanochemical destruction of persistent organic pollutants. Chemical Engineering Journal, 291, 30-38.

4. Cagnetta, G., Robertson, J., Huang, J., Kunlun, Z., & Gang, Y. (2016). Mechanochemical destruction of halogenated organic pollutants: a critical review. Journal of Hazardous Materials, 313, 85-102.

5. Hall, A., Harrowfield, J., Hart, R., & McCormick, P. (1996). Mechanochemical reaction of DDT with calcium oxide. Environmental Science & Technology, 30, 12, 3401-3407.

6. Li, Y., Liu, Q., Li, W., Lu, Y., Meng, H., & Li, C. (2017). Efficient destruction of hexachlorobenzene by calcium carbide through mechanochemical reaction in a planetary ball mill. Chemosphere, 166, 275-280.

7. Lu, M., Lv, T., Li, Y., Peng, Z., Cagnetta, G., Sheng, S., Huang, J., Yu, G., & Weber, R. (2017). Formation of brominated and chlorinated dioxins and its prevention during a pilot test of mechanochemical treatment of PCB and PBDE contaminated soil. Environmental Science and Pollution Research, 24.

8. Lu, S., Huang, J., Peng, Z., Li, X., & Yan, J. (2012). Ball milling 2,4,6-trichlorophenol with calcium oxide: dechlorination experiment and mechanism considerations. Chemical Engineering Journal, 195, 62-68.

9. Nomura, Y., Nakai, S., & Hosomi, M. (2005). Elucidation of degradation mechanism of dioxins during mechanochemical treatment. Environmental Science & Technology, 39, 3799-3804.

10. Nomura, Y., Aono, S., Arino, T., Yamamoto, T., Terada, A., Noma, Y., & Hosomi, M. (2013) Degradation of polychlorinated naphthalene by mechanochemical treatment. Chemosphere, 93, 11, 2657-2661.

11. Zhang, W., Huang, J., Xu, F., Deng, S., Zhu, W., & Yu, G. (2011). Mechanochemical destruction of pentachloronitrobenzene with reactive iron powder. Journal of Hazardous Materials, 198, 275-281. DOI: 10.1016/j.jhazmat.2011.10.045.

12. Zhang, W., Wang, H., Huang, J., Yu, M., Wang, F., Zhou, L., & Yu, G. (2014). Acceleration and mechanistic studies of the mechanochemical dechlorination of HCB with iron powder and quartz sand. Chemical Engineering Journal, 239, 185-191.

APPENDIX 4 - List of Applicable References

2 REFERENCES/Oct18

Technical Reports 1. Cooke, R. J. (2015). GEF/UNDP Project on Environmental Remediation of Dioxin

Contaminated Hotspots in Vietnam: Independent Expert Evaluation of Three Pilot/Laboratory Scale Technology Demonstrations on Dioxin Contaminated Soil Destrution from the Bien Hoa Airbase in Viet Nam. Commissioned by the UNDP.

2. Blansch, K. L., Boeft, K. D., & Tempelman, J. (2018). On the lookout for practicable sustainable options for asbestos waste treatment: A technical, sustainability and market assessment. Commissioned by the Dutch Ministry for Infrastructure & Water Management.

3. USEPA Office of Superfund Remediation and Technology Innovation (2005). Reference guide to Non-Combustion Technologies for Remediation of Persistent Organic Pollutants in Stockpiles and Soil.

4. USEPA National Service Centre for Environmental Publications (2007). Technology News and Trends, Issue 28.

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April 2013 EPA0189

Appendix 5: Standard Operating Procedure

UOA-SOP: Apr19

University of Auckland

School of Chemical Sciences

Handling Persistent Organic Pollutants for Advanced Research and Development:

A Laboratory Operating Procedure

Revision 1: April 2019

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UOA-SOP: Apr19

Contents

Report Details .................................................................................................................................. 3

1. Definitions & Glossary................................................................................................................. 4

2. Scope and Applicability ............................................................................................................... 5

3. Background .................................................................................................................................. 6

4. Method Summary ....................................................................................................................... 7

5. SOP Flow Diagram ....................................................................................................................... 8

6. Health & Safety Warnings........................................................................................................... 9

7. Handling & Storage ................................................................................................................... 10

7.1 Handling ......................................................................................................................... 10

7.2 Tracking Procedures ...................................................................................................... 10

7.3 Storage ........................................................................................................................... 11

8. Equipment & Chemicals ........................................................................................................... 12

8.1 Laboratory Apparatus .................................................................................................... 12

8.2 Laboratory Consumables ............................................................................................... 12

8.3 Reagents ......................................................................................................................... 12

8.4 Analytical Instrumentation ............................................................................................ 12

9. Procedures ................................................................................................................................ 13

9.1 Ball Milling Procedure .................................................................................................... 13

9.2 Solvent Extraction Procedure ........................................................................................ 13

9.3 Jar and Ball Cleaning Procedure .................................................................................... 14

10. Waste Management & Disposal ............................................................................................. 15

10.1 Disposal .......................................................................................................................... 15

10.2 Tracking & Compliance .................................................................................................. 15

11. References ............................................................................................................................... 16

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Report Details

Statement

This document has been prepared in accordance with best practice for a Standard Operating

Procedure (SOP) related to advanced research and development activities. This document is

intended for use by the University of Auckland, School of Chemical Sciences only, with special

consideration for intellectual property rights held by the University of Auckland.

Publication Title

Handling Persistent Organic Pollutants for Advanced Research and Development: A Laboratory

Operating Procedure

Report Reference

UOA-SOP: Apr19

Report Prepared By

University of Auckland, School of Chemical Sciences

APPROVED

Kapish Gobindlal 1 April 2019

Lead Investigator (UoA)

Date

Dr Jonathon Sperry 1 April 2019

Associate Professor (UoA)

Date

David Jenkins 1 April 2019

Hazardous & Containment Manager

(UoA)

Date

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1. Definitions & Glossary

ERM Enterprise Reagent Manager.

HEBM High Energy Ball Milling.

Mechanochemistry A division of chemistry focusing on chemical reactions induced

by mechanical force.

MSDS Material Safety Data Sheet.

NZEPA New Zealand Environmental Protection Authority.

POPs Persistent Organic Pollutants.

PPE Personal Protective Equipment.

R&D Research and Development.

SOP Standard Operating Procedure.

USEPA United States of America Environmental Protection Agency.

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2. Scope and Applicability

The methods described in this Standard Operating Procedure (SOP) are applicable to

laboratory-scale research using POPs, including the development of mechanochemical, or ball

milling, techniques which are used for the degradation of toxic substances listed on the

Stockholm Convention on Persistent Organic Pollutants (POPs). Additionally, this SOP has been

designed to meet the requirements of the New Zealand Environmental Protection Authority

(NZEPA) as part of an importation and containment application of POPs for advanced research

(reference: APP203733).

The primary objectives of this SOP are outlined below:

a. Define the methods for the verification of POPs destruction by advanced degradative

techniques.

b. Describe the procedures in place to safely import, handle, contain, and account for

POPs and POPs-impacted material, i.e. tracking POPs and waste from import through

to disposal should degradation techniques fail to destroy target contaminants.

c. Describe disposal measures for hazardous waste generated as a by-product of R&D

activities.

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3. Background

The purpose of importing POPs is purely for advanced research and development purposes

associated with a novel contaminant degradation technique known as High Energy Ball Milling

(HEBM). This technique can effectively breakdown organic contaminant molecules into inert

by-products and has been involved in lab-scale and full-scale demonstrations globally. This

treatment method is seen a green solution to hazardous waste issues.

The University of Auckland (UoA) has existing infrastructure and internal validation processes

in place specifically for hazardous chemical management. Jaggaer’s Enterprise Reagent

Manager (ERM) is a leading software application that provides UoA staff with a comprehensive

tool to track all chemicals and reagents which have been purchased or imported into UoA. As

an associated benefit, ERM significantly improves inventory use and upholds regulatory

compliance while mitigating the risks related with hazardous materials. In addition to tracking

materials via ERM, UoA routinely conducts internal verification procedures for restricted

substances, including 1080 and controlled drugs. This is achieved using a combination of ERM,

Controlled drug registers and an Electronic Lab Book system. Adopting these and similar tools

together would lead to effective tracking of any imported POPs and POPs-impacted waste.

Security at UoA’s School of Chemical Sciences is given paramount importance and significant

consideration due to the nature of research which is conducted in specialised laboratories

daily. The Organic and Medicinal Laboratory, where POPs research will be conducted, is only

available to authorised personnel and is subject to two-levels of ID card authorisation before

entry. All research will be conducted entirely within a contained modern chemistry laboratory

which meets the requirements of HSNO S33 Exempt laboratory, Part 18 of the Health and

Safety at Work (Hazardous Substances) regulations (2017) as well as laboratory construction

to AS/NZS 2960 and AS/NZS 2243 series. Furthermore, research in this laboratory is conducted

in accordance with:

a. UoA’s School of Chemical Sciences Health and Safety Guidelines (2018).

b. Code of Practice for CRI and University Exempt Laboratories (2004).

The above information provides context for the type of POPs research envisaged, the H&S

precautions which are in place to mitigate exposure risks, and available tools to track POPs

throughout the process.

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4. Method Summary

Small amounts of POPs (microgram to milligram range) will be spiked into silica gel / sand (~5-

10 grams) and placed in a fully-sealed metal grinding jar with metal ball bearings. The custom

jar will be securely fixed in a specialist planetary ball mill and the internal matrix will be

pulverised by the ball-to-ball and ball-to-surface collisions. This high energy grinding process

leads to the degradation of POPs at a molecular scale.

Samples (~1 gram) will be collected and analysed by a range of instrumentation prior to, during,

and after milling to determine intermediate and final breakdown products. Prior research

indicates that POPs end products of the process are inorganic halides, amorphous carbon,

graphitic carbon, water, and small hydrocarbon chains. Organic molecules in the ground

samples will be extracted and analysed in accordance with USEPA Methods 3550C, 8081B,

8270D, and 8290A.

All solid and liquid waste that is generated during this process will be stored in discrete waste

containers which will only be used for the purposes of this research. The nature of the

proposed research and proven capabilities of HEBM to degrade POPs would likely negate the

need to send waste to an overseas location for further treatment, i.e. incineration. However,

this SOP takes a conservative approach by requiring environmentally sound disposal of all

waste at an overseas location, via specialist hazardous waste contractors, in accordance with

HSNO guidelines as outlined in the importation application (reference: APP203733). Section 10

of this SOP details the disposal procedures for all waste that is generated during POPs research

activities. All chemical waste produced at UoA has been appropriately tracked since 2002,

verifying infrastructural capabilities to effectively track hazardous waste.

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5. SOP Flow Diagram

The flow diagram below (Figure 1) outlines the standard method for tracking POPs and POPs-

impacted waste during general research activities.

Receive POPs or

POPs-waste

Add to ERM and E-Lab Book systems

- Maintain a ‘POPs Register.’

Store in locked

hazardous substances cabinet

Jar Cleaning Procedure

Ball Milling Procedure

- Accurately weigh POPs and POPs-impacted waste for E-Lab Book.

Solvent Extraction

Procedure

Analysis

Hazardous Waste

Disposal - Track hazardous waste residues. - Acquire destruction certification.

Figure 1. General SOP flow diagram.

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6. Health & Safety Warnings

Due to the toxic nature of POPs, special care should be taken when handling these substances

during all R&D activities. A catalogue of applicable Material Safety Data Sheets (MSDS) are

available at all times in the laboratory.

The specialist procedures outlined in this SOP must be followed to prevent personal exposure

and environmental discharge of POPs. The Lead Investigator will provide additional instruction

if there are any uncertainties related to specific handling requirements which arise during R&D

works.

Personal Protective Equipment (PPE) is imperative to ensuring the health and safety of

researchers. Appropriate PPE for POPs handling is described in Section 7 below.

All accidents and spills must be cleaned up in accordance with UoA’s hazardous chemical spill

procedures and reported to the Lead Investigator and / or Hazardous Materials Manager.

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7. Handling & Storage

7.1 Handling

All POPs and POPs-impacted waste will be handled in accordance with the MSDS for each

specific POP. Minimum PPE includes:

- Class P2 dust masks for any work outside of a ventilated fume hood.

- Elbow length PVC gloves.

- Chemical protective safety glasses.

- Laboratory coat.

7.2 Tracking Procedures

ERM will be used to track the purchase, import, receipt, and use of POPs and POPs-impacted

waste into the laboratory as well as specifying the exact location An Electronic Lab Book (E-Lab

Book) system will also be used to track the day-to-day usage of POPs and POPs-impacted waste.

Such verification procedures are commonly used at research institutions for tracking illicit

drugs, drug-precursors, and other controlled substances. This existing infrastructure at UoA

supplements the ERM chemical catalogue tracking software. Together, these tools will ensure

compliance with the applicable Health & Safety and HSNO regulations.

7.2.1 ERM:

- Separately enter all POPs and POPs-waste into the ERM network software.

- Required details include:

o Product and chemical information of POP and/or waste.

o Mass of POPs and POPs-impacted waste.

o Available / Unavailable status. POPs and POPS-impacted waste will be made

unavailable to other research groups not listed on the NZEPA application.

o Material / chemical owner.

o Location of POPs and POPs-impacted waste (City > Building > Level > Laboratory

> Cabinet).

o Hazard and precaution alerts.

o Applicable ratings and regulations.

7.2.2 Electronic Lab Book:

- Enter POPs and POPs-impacted wastes into the physical logbook and digital database.

Required details include:

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o Type of POP and/or waste.

o Source of POP and/or waste.

o Concentration of POP as a pure product or constituent of contaminated waste.

o Physical description of POP or contaminated waste.

o Bottle or container description.

o Starting mass in grams of the bottle or container holding the POPs or POPs-

impacted waste.

o Remaining mass in grams of the bottle or container after removing POPs and/or

POPs-impacted waste for experiments.

- The lead investigator of the POPs research group must reconcile the physical logbook

and digital database at the end of every month.

- Weigh each bottle and container of POPs and POPs-impacted waste every six months

to ensure that the remaining mass matches directly to the physical and digital data

entries. This information will be stored on a discrete digital database that can only be

accessed by UoA’s Hazards and Containment Manager.

7.3 Storage

All POPs and POPs-impacted waste will be securely stored in an approved indoor hazardous

materials metal cabinet, meeting the design requirements of section 4.4.2.3 of AS/NZS

4452:1997 or European Standard EN 14470:01. The cabinet will be locked at all times. Cabinet

keys will be held by the lead investigator.

The total mass of POPs and POPs-impacted waste stored will not exceed the maximum

mass/volume threshold of 6.1A hazardous substances (50 litres or kilograms), which is the

most stringent hazardous material class.

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8. Equipment & Chemicals

The equipment, reagents, and chemical standards listed below are directly related to tracking

the degradation of POPs during the HEBM process and determining the intermediate / end

products.

8.1 Laboratory Apparatus

8.1.1 Retsch PM100 Planetary Ball Mill.

8.1.2 Retsch milling jars and balls (stainless steel, tungsten carbide, zirconium oxide).

8.1.3 Ultrasonic bath. Grant XUBA3 44 kHz.

8.2 Laboratory Consumables

8.2.1 Amber USEPA extraction vials.

8.2.2 Amber gas chromatography vials.

8.3 Reagents

8.3.1 Extraction solvents: HPLC-grade toluene, acetone, and dichloromethane.

8.3.2 Internal standard: pentachloronitrobenzene.

8.3.3 Surrogate standard: decachlorobiphenyl.

8.4 Analytical Instrumentation

8.4.1 Gas Chromatography Mass Spectroscopy (GCMS). Agilent 7890A GC System with an

Agilent 5975C MSD triple-axis detector.

8.4.2 Nuclear Magnetic Spectroscopy (NMR). Bruker Avance AV 300 Spectrometer.

8.4.3 Fourier Transform Infra-Red (FTIR). Nicolet spectrometer range.

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9. Procedures

The primary objectives of the following method are to verify the kinetics of POP breakdown

and to determine the mechanisms behind contaminant degradation. The general procedure

has been sectioned into three core segments: (1) Ball Milling Procedure, (2) Solvent Extraction

Procedure, and (3) Jar and Ball Cleaning Procedure.

9.1 Ball Milling Procedure

9.1.1 Accurately weigh POPs / POPs-impacted waste and spike into silica gel or fine quartz

sand to attain a POP(s) concentration between the parts per billion (ppb) and parts per

million (ppm) range. (POPs concentrations will vary during research activities as it is an

integral factor of POPs destruction by HEBM. The total mass of the POPs / sand mixture

will be 5-10 grams).

9.1.2 Note down the actual weights of POPs and sand in the physical lab book and digital

database.

9.1.3 Place the mixture into a fully-sealed and encapsulated metal grinding jar with metal ball

bearings.

9.1.4 Securely fix the jar in into the Retsch PM100.

9.1.5 Vary destruction influencing factors to determine optimal POPs destruction conditions,

i.e. revolution speed, number of balls, chemical composition of jar / balls, inert

additives, residence time, etc.

9.1.6 The internal matrix will be crushed by the metal ball bearings as the jar spins within the

PM100.

9.1.7 Collect ~1 gram sample for analysis prior to, during, and after milling runs. Note the

milling time, sample name, date, time, and target POP on the sample vial.

9.1.8 Following the completion of a milling run, collect all the powdered matrix and place

into a sample vial and label with sample name, date, time, and target POP.

9.1.9 Store sample vials in approved USEPA amber vials. All vials must be labelled correctly

and placed in designated containers which will be stored in a fume hood.

9.2 Solvent Extraction Procedure

Refer to USEPA Methods 3550C, 8081B, 8270D, and 8290A for specific procedural steps related

to the extraction of POPs from solid matrices. A general method is outlined below:

9.2.1 Accurately weigh ~1.0 gram of milled sample into a 20 mL amber vial and blend with

an equivalent amount of anhydrous sodium sulphate.

9.2.2 Spike 1.0 mL of the surrogate standard solution onto the sample.

9.2.3 Add 9.0 mL of HPLC-grade solvent to the vial for extraction.

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9.2.4 Cap the vial and shake using a vortex shaker for 1 minute.

9.2.5 Place the vial into the ultrasonic bath for 30 minutes.

9.2.6 Following sonication, shake each vial to suspend the solid matter and then leave for 30

minutes to settle.

9.2.7 Add 0.1 mL of the internal standard solution to the vial and shake.

9.2.8 Filter the extract through a Whatman 42 (or appropriately rated filter paper) into a 2

mL GC vial.

9.2.9 Cap the rest of the extract and keep aside in a fume hood for disposal following analysis.

9.2.10 Analyse the extract by GCMS to determine POP concentrations. Use NMR and FTIR to

supplement GCMS findings.

9.3 Jar and Ball Cleaning Procedure

9.3.1 Clean the milling jar, lid, and balls of any solid residue with wipes moistened with

hexane and then clean with wipes moistened with deionised water. Dispose of all spent

wipes in a discrete hazardous waste container.

9.3.2 Fill the jar up to 1/3 with clean quartz sand and begin a 1 hour ‘cleaning run’ in the

Retsch PM100 at 500+ rpm.

9.3.3 Collect ~1.0 gram sample for analysis by GCMS to determine the presence of remaining

POPs. Dispose of the remainder of the matrix in an appropriately labelled POPs

hazardous waste container.

9.3.4 Carry out the extraction procedure as outlined in Section 8.2 above.

9.3.5 If POPs are detected after a ‘cleaning run’, then repeat the above steps until the

presence of POPs are undetectable.

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10. Waste Management & Disposal

Quality Control (QC) and waste management measures have been designed into the above

procedures for self-verification related to the consistency of the HEBM process. These controls

determine POPs concentrations in any given matrix and inform disposal requirements. A

general flow diagram is included below (Figure 1).

10.1 Disposal

It is anticipated that relatively small amounts of solid and liquid waste would be produced

during POPs research activities. Per annum rates are:

- < 5 kg of low-level POPs solid waste will be generated following POPs degradation by

HEBM.

- < 24 L of chlorinated liquid waste would be generated from solvent extraction

procedures.

Therefore, all solid and liquid waste resulting from POPs research activities will be discretely

stored and ultimately destroyed at an international facility via an approved New Zealand

hazardous waste specialist. Specialist chemical waste disposal contractors, currently

contracted by UoA, are licensed to remove and transport hazardous substances for suitable

disposal in accordance with the Ministry for the Environment’s Hazardous Waste Guidelines.

10.2 Tracking & Compliance

Final tracking to destruction has been assigned to all research associated with POPs. Service

solutions which meet this stringent compliance requirements are:

- Specialist tracking applications providing a completely transparent trail of waste from

removal by licensed providers to final destruction.

- Destruction certificates, which documents information about the final destruction of

all solid and liquid waste generated as part of POPs-related research.

It should be noted that all chemical waste generated at UoA has been tracked since 2002,

substantiating organisational capabilities to effectively track hazardous waste.

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11. References

NZ Ministry for the Environment. (2018). Hazardous Substances and New Organisms Act 1996.

New Zealand Legislation.

NZ Ministry for the Environment. (2017). Hazardous Substances (Classification) Regulations

2001, SR 2001-113. New Zealand Regulations.

U.S. Environmental Protection Agency. (2007). Guidance for Preparing Standard Operating

Procedures (SOPs): EPA QA/G-6, EPA/600/B-07/001. Office of Environmental Information,

Washington DC.

U.S. Environmental Protection Agency. (2007). EPA Method 3550C: Ultrasonic Extraction,

Revision 3. Retrieved from: http://www.epa.gov/.

U.S. Environmental Protection Agency. (2007). EPA Method 8081B: Organochlorine Pesticides

by Gas Chromatography, Revision 2. Retrieved from: http://www.epa.gov/.

U.S. Environmental Protection Agency. (1998). EPA Method 8270D: Semivolatile Organic

Compounds by Gas Chromatography / Mass Spectrometry (GCMS), Revision 4. Retrieved from:

http://www.epa.gov/.

U.S. Environmental Protection Agency. (2007). EPA Method 8290A: Polychlorinated Dibenzo-p-

Dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) by High Resolution Gas

Chromatography / High Resolution Mass Spectrometry (HRGC/HRMS), Revision 2. Retrieved

from: http://www.epa.gov/.

application form: import or manufacture a persistent ... · novel methods of remediation of pfos...

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