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1Wastewater Treatment Guide

WATER TECHNOLOGIES

PERSONAL CARE PRODUCTSWastewater Treatment Guide

Personal Care Products 2


This guide offers an expert overview of the challenges posed in treating wastewaters from Personal Care Products manufacturing facilities and the processes employed to manage them.

Veolia Water Technologies has been meeting industries’ water and wastewater needs for over

160 years. Within the PCP industry it has over 100 reference projects throughout the world; many

of them with industry leaders. This guide draws upon Veolia's experience in helping PCP clients

comply with legislation, meet sustainability objectives, reduce risk and optimize costs.

CONTENTS

1. INTRODUCTION • Definition & classification of PCP • Characterization of PCP wastewaters - Substances present in PCP wastewaters - Wastewater volumes - Wastewater characteristics

2. TREATED WATER QUALITY • Discharge quality values • Emerging pollutants • Questionnaire/laboratory tests

3. KEY PROCESSES IN PCP WASTEWATER TREATMENT • Type of pollution & processes to remove it • Key processes

4. TYPICAL TREATMENT LINES • WASTEWATER TREATMENT

A-EQUALIZATION TANK > DAF> MBBR > DAFB-EQUALIZATION TANK > DAF > MBBR > ACTIVATED SLUDGE > CLARIFICATION C-EQUALIZATION TANK > DAF> MBR D-EQUALIZATION TANK > EVAPOCONCENTRATION > MBR

• WASTEWATER TREATMENT FOR REUSE E-EQUALIZATION TANK > DAF > MBR > GAC FILTER-RO -DISINFECTION F-EQUALIZATION TANK > DAF > MBBR > DAF > DMF + GAC > RO > DISINFECTION G-EQUALIZATION TANK > DAF > ACTIVATED SLUDGE > CLARIFICATION > UF > RO > DISINFECTION

5. GLOSSARY

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1. INTRODUCTIONIn today’s Personal Care Products (PCP) facilities, an effective wastewater treatment is essential. The production of shampoos, perfumes or skin moisturizers use water and a variety of compounds that inevitably find their way into the plant's effluent in varying concentrations. Although the human health effects of many of these compounds is seen as positive, their environmental impacts to various wildlife and broader impacts from widespread environmental exposure may be questionnable. Implementing an efficient wastewater treatment may well be a legal obligation for the PCP manufacturers, increasingly sustainable development and cost control are also key drivers. This guide aims to give an overview of the existing treatment processes applicable to this industry.

A. DEFINITION AND CLASSIFICATION OF “PERSONAL CARE PRODUCTS”

The term "personal care products" refer to a wide variety of items that are commonly found in the health and beauty sections of department stores. The term "personal care product", however, is not defined by law. In Europe the term “cosmetic product” is used within European regulations. It is defined as any substance or mixture intended to be placed in contact with the external parts of the human body (epidermis, hair system, nails, lips and external genital organs) or with the teeth and the mucous membranes of the oral cavity with a view exclusively or mainly to cleaning them, perfuming them, changing their appearance, protecting them, keeping them in good condition or correcting body odors .i

In the USA, some "personal care products" meet the definitions of both cosmetics and drugs. This may happen when a product has two intended uses. For example, a shampoo is a cosmetic because its intended use is to cleanse the hair. An antidandruff treatment is a drug because its intended use is to treat dandruff. Consequently, an antidandruff shampoo is both a cosmetic and a drug, because it is intended to cleanse the hair and treat dandruff. Such products must comply with the requirements for both cosmetics and drugs.

In this guide, personal care products are classified as follows:1- Skin care products including facial care, hand care, body care and sun protection; 2- Hair care products including shampoos, conditioners and styling agents;3- Hair dyes;4- Make-ups;5- Deodorants and fragrances;6- Oral care products.

B. CHARACTERIZATION OF PCP WASTEWATERS

The PCP industry accrues many kinds of wastewater. PCP wastewaters come primarily from the cleaning and rinsing of the mixing tanks after or between the production runs of different products. As such, knowledge of the products manufactured by a factory gives an indication of the nature of the wastewater and its pollutants. It is, however, also necessary to take into account the quality variations that may arise due to: • the specific formulations used for the products being

manufactured;• the variety of products being manufactured at the site

and how the production ratios change over time in response to market demand. Some sites manufacture only one category of products (monoproduction) while others produce many different categories of products (multiproduction)

• the addition of a new line of products for the production site

• the production management approach being used at the site.

• the inclusion of sanitary effluent in the wastewater B1. SUBSTANCES PRESENT IN PCP WASTEWATERSPCP wastewaters contain various compounds, both organic and inorganic. Among the organic compounds the following stand out: hydrocarbons, proteins, ethers, esters, aldehydes and ketones, alcohols, carboxylic acids;

ⁱ http://ec.europa.eu/consumers/sectors/cosmetics/files/doc/manual_borderlines_ol_en.pdf https://www.fda.gov/Cosmetics/GuidanceRegulation/LawsRegulations/ucm074201.htm


along with more complex derivatives and the products resulting from various biochemical transformations. Inorganic compounds include: acids, hydroxides, salts, oxides and metal compounds. These substances perform various roles in PCPs: they may form the base (carrier) of the PCPs formulations or be active ingredients. The active ingredients include moisturizers, fragrances, surfactants, antiseptics, colors, vitamins, UV filters and others.Some of the substances found in PCP wastewater are scarcely biodegradable. This is the case for not only surfactants and organic dyes but also for fragrances and sunscreen UV filters.

Some of the pollutants commonly found are:

> Oils and GreasesOils and greases are the main constituents of PCPs. They are found in a variety of products applied externally, for example skin care products such as creams, lotions, lipsticks, and massage oils as well as hair care products such as shampoos, conditioners. Some of them are present in PCPs wastewaters as free type and some as emulsions due to the presence of surfactants.

Wastewater consequences: the presence of Oil & Grease has an impact on the efficiency of the biological treatment stage as it can be absorbed on the surface of the biomass, which may limit the transfer of soluble substrates and oxygen to it. Additionally, the overall oxygen consumption may increase significantly if the Oil & Grease degrade instead of separating, which will lead to higher Operating Expenditure (OPEX). Their removal prior to biological treatment is therefore key.

> SurfactantsSurfactants are a very common and useful ingredient in PCPs. They are used for cleansing (detergents), emulsification, solubilization, conditioning and special effects. Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. It is a chemical with parts that are both hydrophilic (strong affinity for water) and lipophilic (strong affinity for lipids/oils). So, when you put a surfactant solution on a surface like hair or skin, the oil that is there will be drawn away from the surface and into the micelles. When the surfactant solution is rinsed away, the surface is clean.Surfactants can be sorted according to the charge characteristic of their polar (hydrophilic) head: anionic, cationic, amphoteric and non-ionic.

Wastewater consequences: Considering the high concentration of surfactants in PCP wastewaters together with fatty compounds, physical-chemical coagulation is today seen as the most efficient process to remove them. They also increase the dosing rate of flocculant/coagulant in the primary separation step (non-ionic surfactants in particular). The presence of surfactants is the main cause of foam issues in wastewater treatment plants.

Foaming in biological tankThe phenomenon is observed on all biological pro-cesses, with varying degrees of gravity. It occurs with effluents containing high concentra-tions of surfactants. The formation of foam is due to and amplified by the aeration of the tank.

Solutions:• Design sufficient freeboard between the water level

and the top of the tank• Control foam using an air-lift pump or a sprinkler

system in the biological tank • Dose antifoam agents in the effluent before feeding

the biological tank – the type of antifoam is to be selected cautiously

> ParabensThe use of parabens as preservatives is due to their efficient antimicrobial properties: they have a wide reach covering bacteria, yeasts and fungi. They are used in products such as creams, lotions and deodorants. Some, however, are thought to be endocrine disruptors and as such their use within PCPs is strictly controlled. In Europe, certain parabens are banned for use in PCPs (isopropylparaben, isobutylparaben...) Others such as propylparaben and butylparaben have recently been included in European Directives that limit their concentrations and even their usage within products destined for infants3.

Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic- Article 14


Wastewater consequences: As an emerging pollutant, it is important to consider the removal of parabens before discharge to the environment. Emerging pollutants are difficult to remove. Technologies focused on adsorption, filtration, separation, concentration and oxidation show the greatest potential for their removal. The technology has to be carefully selected as there is not a unique technology to treat all emerging pollutants.

> SiliconMost PCPs contain silicon. Silicon is widely used as it offers the following advantages: it gives a supple and soft texture to creams and foundations; and shampoos containing silicon result in silky and shiny hair. Silicon is an inorganic compound formed of molecular chains of silica and oxygen.

Wastewater consequences: Silicon is not biologically degradable and is a high clogging product. It can be eliminated by physical or physical-chemical treatment (coagulation/flocculation + flotation). Where biological treatment and membranes (MBR) are employed , sillicon needs to be removed upstream.

> 1-4 Dioxane1-4 Dioxane belongs to the list of substances prohibited in cosmetic products under European Regulation but is yet unregulated in both China and the U.S3.The compound 1-4 Dioxane itself is not used as an intentionally added ingredient in cosmetic or personal care products. It is a manufacturing by-product that may be present in extremely low levels in some cosmetic and PCP ingredients.

Wastewater consequences: It is difficult to degrade and as such is removed partly by stripping.

> Organic dyes and pigmentsThe colorants commonly found in PCPs are ammonia based, like p-Aminophenol, p-Phenylenediamine, p-Methylaminophenol,...

Wastewater consequences: It may be toxic for biological treatment depending on the concentration.

> Zinc Pyrithione (ZnPT)Zinc Pyrithione is the active ingredient most commonly used in anti-dandruff shampoos, because of its ability to prevent the growth of microorganisms.

Wastewater consequences: In high concentrations ZnPT can be toxic and may even kill the bacteria in the biological treatment process. If a biological treatment stage is required, then this compound must first be removed by dosing a specific chemical (metal chelating agent) prior to the primary clarification stage.

> MetalsCombined or oxidized metals are used in inorganic colorants, titanium dioxide, red iron oxide, ferric ammonium ferrocyanide and chromium hydroxide green. Zinc oxide is used as a UV filter in cosmetic products.Heavy metals are not used specifically as ingredients for PCPs but some very small traces of heavy metals are tolerated in PCPs as long as they have no negative effect on human health⁴. These traces come from impurities in certain synthetic or natural raw materials (colors, pigments,...) from the manufacturing, storage or packaging processes.

Wastewater consequences: Heavy metals (Zn …) contribute to toxic compounds that can inhibit the biological treatment process; especially the removal of Nitrogen.

> Fragrance ingredientsFragrance ingredients are organic compounds with characteristic, usually pleasant, odors. They are ubiquitously used in perfumes and other perfumed cosmetic products. Nowadays many modern perfumes contain synthesized odorants. One of the most commonly used classes of synthetic aromatics by far is synthetic musks. They belong to two main categories: nitro musks and polycyclic musks.At some PCP plants, Veolia has observed high

Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic- Article 14 ⁴Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic -Article 17


concentrations of fragrances in the atmosphere around the WWTPs (over 5000 ng/m in a PCP factory in China, for example). It is logical considering the fragrances are semi-volatile organic compounds, but such phenomenon must be taken into account as the PCP plant could be a source of air pollution and odor.

Wastewater consequences: Because fragrance ingredients have a wide range of physical-chemical properties and biodegradability, understanding their removal in the treatment process is complex.The mechanisms of their removal from wastewater include: biodegradation, sorption, volatilization. The removal efficiency is also highly dependent on plant operation and design.One example of a removal process is adsorption on sludge. Higher adsorption efficiency occurs on the chemical sludge in the primary clarifier, rather than on the biomass sludge in the secondary clarifier. Because of the lipophilicity, fragrance can also be removed together with Fat, Oil and Grease (FOGs) through physical-chemical processes.

B2. WASTEWATER VOLUMESDaily flow rates are relatively small: from 50 to 300 m/d or even smaller on specific projects using evaporation processes, where the daily flow rates are usually below 30 m/d.Within production sites, and due to batch production techniques, there are often fluctuations in volume and quality of wastewaters.

B.3 WASTEWATER CHARACTERISTICSThe characteristics of PCP wastewaters vary according to the type of product being produced, the site, the batch, etc. This makes it difficult to generalize the quality of PCP wastewaters. However, there are some recurring characteristics. The values presented below are drawn from a study by Veolia Water Technologies (Veolia).

> High Chemical Oxygen Demand (COD)PCP wastewaters are concentrated waters with very high CODs. Values range from 10 000 to 30 000 mg/l. In the case of hair dye manufacturers these values can reach 45 000 mg/l.

> High Biological Oxygen Demand (BOD5)This value is not systematically communicated in tender documents and it is the ratio COD/BOD5 that is often

preferred. However, BOD values are typically high: 2 000 to 10 000 mg/l.

> Variety of COD/BOD5 ratioThe most common way to assess the biodegradability of PCP effluent is the COD/ BOD5 ratio, for which the following limits have been established by Veolia:COD/BOD5 < 2: effluent is easily biodegradableCOD/BOD5 2-3: effluent is biodegradableCOD/BOD5 > 3: effluent may not be biodegradable; further analysis required.In PCP industries values range from 2 to 4. However this ratio does not provide information on the fraction of COD that is non-biodegradable or very difficult to degrade biologically, called Refractory COD.

> Refractory COD/Non-biodegradable dissolved CODRefractory COD is principally due to the presence of organic molecules, which are difficult to degrade. These substances are often derived from chemical synthesis. In PCP wastewaters these substances may be polycyclic aromatic hydrocarbons (PAH) found in some shampoos, mineral oils, dyes, ...etc. Refractory COD is also generated by the presence of substances and compounds that inhibit the metabolic functions of the microorganisms. This inhibition can be induced by heavy metals but also organic substances such as active biocides (bactericides ...) Depending on the effluent, refractory COD may vary widely. The highest values observed are for wastewaters from hair dye production plants.

Refactory COD is a critical factor as it limits the ability to reach low COD discharge limits through biological treatment only. The estimation of refractory COD will mainly be based on experience from treatment results obtained from treating similar wastewaters. If no experience is available, or in case of doubt, the degradability can be determined through lab tests.Refractory COD is also referred to as “hard COD”, “ultimate COD”, “persistent COD” or “inert COD”.

> Fat, Oil and Grease (FOG)Values observed are between 150 and 6 000 mg/l. FOG is the main pollutant in PCP wastewaters and

Total COD(mg/l)

Refractory COD (mg/l)

Example 1: Hair dye 10 000 - 20 000 800-1500Example 2: Skin cream 8500 200-300Example 3: Shampoo 11 500 600Example 4: Shampoo 12 500 200


WASTEWATER TREATMENT IMPACTS DEPENDING ON THE PCP TYPE

Segment Main compounds Wastewater Treatment Impacts

Skin care products

High FOG content Reduces biological treatment efficiency and provokes membrane clogging

Silicon Non degradable in biological treatment and leads to membrane clogging

Detergents and surfactants Encourages foaming

Presence of heavy metals in sunscreen products May be toxic for biomass in biological treatment

Haircare products

High FOG content Reduces biological treatment efficiency and provokes membrane clogging

Silicon Non degradable in biological treatment and leads to membrane clogging

Detergents and surfactants Encourages foaming

Presence of Zinc Pyrithione (ZnPT) in anti-dandruff shampoos

Toxic for biomass in biological treatment and special attention required if Zn is a parameter for treated water

Hair dye

Extremely high COD content Choice and design of key process

Extremely high color High residual color even after biological treatment

High concentration of refractory COD Non-biodegradable, to be eliminated by an alternative process

Make-up products Presence of metals Difficult to treat – specific tests needed

Deodorants, fragrancesPresence of aluminum salts in deodorants Difficult to treat – specific tests needed

Semi Volatile Organic Compound Aerosol formation

contributes to 60 to 80% of COD. Therefore, its removal is essential.

> Total Suspended Solids (TSS)TSS is the total amount of suspended solids in the wastewater (suspended organic solids + suspended mineral matter).Values observed are high and vary greatly between sites: from 700 to 10 000 mg/l.

> Total Kjeldahl Nitrogen (TKN)TKN is made up of ammonia (N-NH4+) and organic nitrogen. Values observed are between 20 and 200 mg/l.

> Total Phosphorus (Pt)Total Phosphorus values are rarely communicated in tender documents. Values observed are between 1 mg/l and 20 mg/l.

> TemperatureTemperature at the entry point of a wastewater treatment plant: from 10°C to 60°C. It is an important parameter as some treatment processes, such as biological treatment, are temperature sensitive. Membrane processes are also sensitive with most membranes struggling at temperatures exceeding 35°C.

> Microbiological parametersIf sanitary effluents are mixed with industrial wastewater, microorganisms will be present in the wastewater (bacteria, etc.).

> pHpH values at the entry point of a wastewater treatment plant vary from 4 to 9.5. pH should be corrected in order to ensure efficiency at each stage of treatment and to ensure that the treated water meets regulatory requirements, usually between 6.5 and 8.5.


A. DISCHARGE QUALITY VALUES

2. TREATED WATER QUALITYTreated water may be discharged to the natural environment (river, lake or sea), sent to the municipal water treatment plant or to a centralized industrial water treatment plant, or treated water may be reused. The discharge quality required depends on the destination.Guaranteed parameters are usually: COD, BOD, TSS, TKN (or N-NH4), TN, pH and Pt. Total Nitrogen (TN) is the sum of TKN, nitrates and nitrites.For a treatment line with reuse, guaranteed parameters could be turbidity, conductivity, and total dissolved solids (TDS). Specific parameters may also be requested to be guaranteed: Zn, SO4, parabens, microbial contamination (CFU). The values depend on the type of discharge and the local legislation.

Examples Unit Example 1 Example 2 Example 3 Example 4 Example 5

Discharge To Municipal WWTP (Asia)

To River(Europe)

To River(Europe)

To Industrial Park WWTP (Asia)

To Re-use(Europe)

pH mg /l - 6.5-8.5 6.5-8.5 - 6.5-8.5

COD mg /l 500 250 125 800 15

BOD5 mg /l 100 15 25 500 -

TSS mg /l 400 15 35 400 Particle size < 10 µm

N-NH4 mg /l 100 - - 10 15

TKN mg /l - 10 - - -

TN mg /l - 30 - - 50

Pt mg /l - 10 10 - -

Otherparameters NTU -

E.Coli< 100 CFU /100 ml -

- Oxidability KMnO₄ < 5mg/l O₂- Turbidity < 5 NTU- Colorless- Hardness < 1°F- Parabens < 10 mg/l - Colony count 22°C <100 CFU/ml- Zn < 3 mg/l


B. EMERGING POLLUTANTS

UNESCO defines emerging pollutants in a broad sense as any synthetic or naturally-occurring chemical or any microorganism that is not commonly monitored or regulated in the environment with potentially known or suspected adverse ecological and human health effects.

These contaminants include mainly chemicals found in pharmaceuticals, personal care products, pesticides, industrial and household products, metals, surfactants, industrial additives and solvents. Many of them are used and released continuously into the environment even in very low quantities and some may cause chronic toxicity, endocrine disruption in humans and aquatic wildlife and the development of bacterial pathogen resistance⁵Some cosmetic ingredients are considered as emerging pollutants. For example: UV-filters, some preservatives (parabens, triclosan) and plastic microbeads (present as abrasive scrubbers in hand-cleansers, toothpaste...)⁶

The lack of scientific data about health effects today means that few emerging pollutants are regulated anywhere in the world. In 2008, the European Union developed a mechanism which aims to support the identification of priority substances for regulation under the Water Framework Directive⁷.

C. QUESTIONNAIRE/LABORATORY TEST/ BENCH TEST/PILOT/TEST AUDIT

Wastewaters are often unique and complex. It is thus important to obtain a maximum amount of details about the production site and the nature of its effluent in order to design an effective and efficient treatment line. A detailed questionnaire can help with this and is essential for defining an effective water treatment line.

*Example extract of a questionnaire

> Questionnaire*Using the data collected from the questionnaire, one can study the treatment line and propose a variety of possibilities to the client (See example extract below).

> Lab testsIn some cases - if the COD/BOD5 ratio looks unfavorable or if the effluents contain pollutants potentially toxic or challenging for biological treatment - wastewater treatability tests may be proposed in order to check the biodegradability of the compounds. For effluents coming from the production of make-up products, deodorants and fragrances, bench scale tests are essential. For a treatment line using evapoconcentration, bench-scale testing is systematic. The tests are used to assess concentration rates and distillate quality.

Bench-Scale testing on an Anox Kaldnes Moving Bed Biological Reactor (MBBR)

> Pilot-scale testingIn some cases, pilot tests may be proposed. Their objective depends on the nature of the project but they can give data on the scale of the size of the treatment works, the consumption of chemicals or the stability and efficiency of various solutions...

⁵Emerging Pollutants in Water and Wastewater – UNESCO

Parameters Units Minimum Maximum AverageWaste water discharge(from production process)

- Continuous /discontinuous

Volume of effluents to be treated m/dMaximum flow rate (pick value) m/h / /Colour -pH -Temperature °CSuspended Solids mg/lDry Matter mg/lCOD total mgO₂/lCOD biodegradable mgO₂/lCOD not biodegradable mgO₂/lBOD₅ mgO₂/lCOD/BOD₅ -mg/l NTK mg/l


B. KEY PROCESSES

B.1 EqualizationWhat is an equalization tank?An equalization tank is a tank installed at the head of the wastewater treatment plant (WWTP) where the wastewater is stored during a certain period prior to the treatment.

Why install an equalization step in a PCP wastewater treatment plant (WWTP)?PCP wastewaters come primarily from the cleaning and rinsing of the mixing tanks after or between the production runs of different products. This batch processing leads to high variability in the wastewater quality. The aim of the equalization step is to buffer the wastewater.

What are the results of the equalization step?• It smooths peaks of flow and pollution: equalizes

the flowrate, balances the pollution, evens out temperature fluctuations

• It minimizes chemical usage (e.g., downstream pH adjustment): optimizes downstream design and operating costs

• It improves reliability of the WWTP: reducing the downstream impact from inhibitory compounds

B.2 PretreatmentWhat is pretreatment?Pretreatment is a preliminary treatment of the wastewater, usually a physical treatment. For PCP wastewaters the pretreatment is typically screening. Different type of screening can be used: coarse screening (10 to 25 mm), fine screening (<10 mm), rotary screening... The screens remove matters such as paper, plastics, fibers.

A. TYPE OF POLLUTION AND PROCESSES TO REMOVE IT

3.KEY PROCESSES IN PCP WASTEWATER TREATMENT

TSS & Colloids FOG Biodegradable COD / BODRefractory COD

Coagulation-Flocculation + Flotation

Sedimentation

Filtration

Grease & Oil removal

Coagulation-Flocculation + Flotation

Biological TreatmentChemical TreatmentEvapoconcentration

Activated carbon adsorptionMembrane filtration

AOP (Advanced Oxidation Process)

TKN Pt pH Temperature TDS Microbialparameters

BiologicalTreatmentStripping

ChemicalPrecipitation

BiologicalTreatment

Neutralisation Cooling EvaporationReverse Osmosis

MembraneFiltration

Disinfection

The key processes in bold letters above are described in more detail within this technical guide.Wastewater segregation may be required for effective treatment, for example where hair dye is present in the effluent.

Diagram of screening

⁶Cosmetic Ingredients as Emerging Pollutants of Environmental and Health Concern. A Mini-Review by Claudia Juliano* and Giovanni Antonio Magrini - Department of Chemistry and Pharmacy, University of Sassari, Via Muroni 23/A, 07100 Sassari, Italy⁷Directive 2008/105/EC, as amended by Directive 2013/39/EU, in the field of water policy

Diagram of an equalization tank


Why install pretreatment for PCP wastewaters?The pretreatment prevents damage and clogging of the downstream equipment, piping, valves, etc.The choice of the pretreatment step is made according to the needs of the downstream treatment stages.

What are the results of the pretreatment step?Issues with downstream treatment processes may be avoided: for example, clogging of the membrane if an MBR is chosen, clogging of the outlet sieves if MBBR is selected...

B.3 NeutralizationWhat is neutralization?Neutralization is the process of adjusting the pH of water through the addition of an acid (sulfuric acid, for example) or a base (caustic soda), depending on the target pH and process requirements.

Why install neutralization in PCP wastewater plants?A pH neutralization stage is used to ensure that the pH value is within a suitable range for downstream treatment stages.

What are the results of the neutralization step?Processes like coagulation are pH dependent so the pH has to be adjusted to achieve maximum process efficiency. Also optimal pH for any biological treatment is around neutrality (6.5-7.5).

B.4- Primary separationIn primary separation, the total suspended solids that can settle and float are removed from the wastewater. The primary separation of PCP wastewaters is usually used in combination with the addition of a metallic salt in coagulation/flocculation tanks. This chemical precipitation separates the “difficult-to-settle” suspended solids (colloidal organic substances and fine mineral solids etc.) and FOGs which are dissolved in water as emulsions.

What is DAF?Dissolved Air Flotation (DAF) is a primary separation process where contaminants are removed through the use of an air-in-water solution (called “whitewater”) produced by injecting air under pressure into the raw water (direct flotation) or a recycle stream of clarified DAF effluent (indirect flotation). The bubbles attach themselves to particulate matter in the wastewater and cause them to rise to the surface where the sludge formed is removed by scrapers into a sludge holding tank. It is also necessary to collect and discharge the settled matter at the bottom of the DAF.

Why install DAF in a PCP wastewater treatment plant?Dissolved Air Flotation (DAF) is usually the most suitable technology for primary separation of PCP wastewaters.Indeed DAF is ideally suited to particles that are slow settling, of neutral density or buoyant. This is particularly applicable to PCP wastewater where FOG content is very high.

Diagram of a neutralization tank Diagram of a Dissolved Air Flotation tank (DAF)

Consequence of poor screening prior to an MBBR process: clogging of outlet sieves


DAF with lamellae (IDRAFLOT™)

Due to the presence of surfactants, some FOGs will not be in free phase but rather dissolved in water as an emulsion. The addition of metallic salt will break the link between them and the surfactants ( in the coagulation tank). The addition of flocculant (in the subsequant flocculation tank) will promote floc formation and improve the recovery of small flocs. Best Practice: In traditional or circular flotation units with traditional saturation systems, small flocs (having a very low ascent speed according to Stokes law) have the tendency to come out with the treated effluent. Therefore designs with corrugated plate surface lamellar packs are preferred today. The lamellae encourage the aggregation of small flocks, increasing their size, speed and their separation.

What are the results of the DAF step?• A chemically enhanced DAF will remove most FOGs, TSS

and some COD, thus reducing load on the downstream treatment stages

• It eliminates most silicon responsible for membrane treatment problems

• It removes the majority of surfactants responsible for foaming in biological treatment

B.5 CoolingWhat is cooling?The objective is to reduce the wastewater temperature. The wastewater passes through a heat exchanger so that the outlet temperature does not exceed a set limit.

Why install a cooling step in wastewater treatment plant?Temperature restrictions on biological treatment dictate that streams with a temperature higher than the permitted level need to pass through a cooling system to reduce the effluent temperature.Indeed the degradation of the organic matter for high

COD loads can lead to a non-negligible temperature rise in the biomass.

What are the results of the cooling step?Cooling allows for correct and efficient operation of downstream processes.

B.6 Biological treatmentWhat is biological treatment?Biological treatment uses bacteria to convert biodegradable organic matter contained in wastewater into simple substances and additional biomass. There are two types of biological treatment: aerobic and anaerobic.

Why install biological treatment in PCP wastewater treatment plants ?PCP wastewaters are concentrated waters with very high COD. When this organic pollution is biodegradable, biological treatment is the least expensive method for COD removal.

What is aerobic treatment?In aerobic treatment, aggregates or flocs of bacteria (biomass) form when the tank containing the wastewa-ter is aerated: microbial colonies and oxygen combine to breakdown the organic matter present in the wastewater. The resulting bacteria aggregates are then separated from the treated water.

Diagram of a heat exchanger

PCPWastewater

Air, nutrients

CO₂,

H₂O

New

cells

(Bio

mas

s)

TreatedWastewater


In a conventional activated sludge process, the biomass is free floating and a clarifier is employed to separate the biomass from the treated water.

What are the results of the aerobic treatment?The aerobic treatment removes:• BOD and most COD, down to refractory COD• Removes TSS in the separation stage• Removes N if required,

B.7 Advanced aerobic treatmentConventional activated sludge is one of the oldest processes that exists for the treatment of carbonaceous or nitrogenous pollution. It is widely used, but it is also limited in terms of water quality, modularity, integration and ease of operation. For example, it is frequent that the biological sludge of PCP wastewater does not settle easily in a conventional clarifier. To overcome these limitations the industry has developed other aerobic treatments, as detailed below.

B.7.1 Membrane Bio Reactor (MBR): What is a Membrane Bio-Reactor?A Membrane Bio-reactor is an aerobic biological treatment where the clarifier is replaced by a selective barrier that retains the biomass (suspended matter and bacteria) while allowing dissolved matter to pass through. This membrane also retains colloidal matter, organic macromolecules, microorganisms...The implementation of an MBR process consists of one or more activated sludge basins and membrane modules.

Why install an MBR in a wastewater treatment plant?Sometimes with a traditional activated sludge process, troubles are observed in sludge separation during the final clarification stage. The presence of the membrane

avoids all of these problems and also makes the treatment line more compact. The use of a membrane changes the definition of the soluble part of the pollution since - depending on the membrane retention threshold - most colloids cannot go through the membrane walls. This leads to a significant increase in COD removal compared to conventional activated sludge system (CAS). MBRs are therefore very competitive for treating highly concentrated wastewaters and they produce the highest quality treated water of any of the biological processes.

The treatment fields and applications of the MBR process for PCP wastewaters are:

What are the results?The performance of the MBR treatment:• 95 % removal of COD, down to refractory COD• 99% removal of BOD• 99% reduction in TSS• Removes N if required, to Total N concentration

comparable to CAS effluent• Reduction of 4-5 log of Total Coliforms

B.7.2 Moving Bed Biofilm Reactor (MBBR)What is MBBR?MBBR is a biological process based on the biofilm principle. It consists of an aeration tank with special plastic carriers that provide a surface where a biofilm can grow. A biofilm is a group of microorganisms and their extracellular polymeric substances (EPS) attached to a surface. The microorganisms that develop on the carrier surface are essentially from the same group as those found in conventional activated sludge.

Why install an MBBR in a PCP wastewater treatment plant? Due to the development of the biofilm, the MBBR is capable of handling both load and composition variations in pollution which may occur in some PCP wastewaters

Diagram of a Membrane Bio-Reactor (MBR)

Treatment of carbon pollution > Highly concentrated influents

> Tight layout requirement> Stringent discharge requirements> Refurbishment of existing plants

Treatment of nitrogen pollutionSimultaneoustreatment ofcarbon, nitrogen and phosphorousPhysical disinfection (especially withrespect to bacteria)

> Need for a high water quality : recycling of water treated on site, re-use of water for irrigation or in-dustrial needs, stringent discharge requirements> Pretreatment for reverse osmosis

Diagram of a Conventional Activated Sludge (CAS)


even after the equalization step. The MBBR is also more compact that a CAS, making it a good choice where lack of space is an issue.

The MBBR process can be applied to most carbon and/or nitrogen removal applications:

What are the results of the MBBR?The removal efficiencies achieved are comparable to those obtained in conventional activated sludge system, however, due to higher activity in the biofilm, the volume of the MBBR reactor is greatly reduced.As with other biological processes, the amount of refractory COD in wastewater limits the possibilities for reaching a certain discharge limit for COD by biological treatment only. The minimum discharge limit for total COD that is possible to achieve will thus be determined by the degradability of the wastewater and the efficiency of the applied clarification.

There are several configurations of MBBR that may be considered. The choice of the most suitable option depends on the type of effluent, the requirements on treated water quality, the existing treatment and the available tanks, if any. Based on Veolia Water Technologies' experience (Veolia) in treating PCP wastewaters, the two following options are most suitable:

Treatment of carbon pollution For new plants, especially those

requiring a small footprint and easy operation

For upgrading an existing activated sludge (by adding carriers to the existing tank)

Treatment of nitrogen pollutionSimultaneous treatment of carbon and nitrogen

Pre-treatment as a roughing reactor (high-loading system)

For existing plants in front of an existing biological treatment stage

Post-treatment for process improvements

For existing plants after an existing biological treatment stage

Diagram of a Moving Bed Biofilm Reactor (MBBR

Configuration: MBBR+Clarifier This combination (AnoxKaldnes™ pure MBBR for Veolia) consists of one or more MBBR tanks followed by a clarification step:

Performance of the MBBR + Clarifier configuration: 80-90% removal of COD

MBBR+Clarifier configuration is the first choice when… Why?

Partial organic matter removal is required Biodegradable compounds which are slow to degrade will not be degraded within the process due to the short retention time

There are large variations of load and composition Insensitive to temporary limitations such as pH, temperature or toxicity

For toxic wastewaters Simple to create multi-stage system with specialized microor-ganisms to handle particular compounds

Compact plant is needed Small footprint

Robustness is needed No sludge bulking

Easy operation is an important parameter Self-controlling biomass


Performance of the MBBR + AS configuration: >95% removal of COD

MBBR + Activated Sludge configurationis the first choice when : Why?

• An existing activated sludge plant needs upgrading

• Maximum biological organic removal is needed• One or more specific compounds which are not readily

biodegradable need to be removed• There are variations in load and composition• Robustness is needed• Low effluent TSS concentration is required without addi-

tion of chemicals• Low sludge production is important

• The existing activated sludge tank can be used either as an MBBR tank or remains as an activated sludge tank

• The two (or multiple) stage biological treatment allows for the removal of the slowly biodegradable COD

• The process is stable and robust; the start-up and restart after disturbance is faster than a CAS. Bulking risk is limited due to the quality of sludge.

• Sludge production yield is lower than in CAS, especially in nutrient limited operation

Configuration: MBBR + Activated sludge This combination (BAS™ for Veolia) consists of one or more MBBR tanks followed by an activated sludge system. In this system a large part of the readily biodegradable organic pollution is removed in the MBBR tank while the slowly biodegradable COD will be removed in the activated sludge tank. The volumes of the both biological steps will be reduced. A useful configuration when there is a lack of space.

B.8 Anaerobic treatment What is anaerobic treatment?Anaerobic treatment or "methanization" is a biochemical process carried out by several types of micro-organisms in an oxygen-free environment. Anaerobic treatment can be applied wherever the wastewater is biodegradable, but is most suitable for high concentrations of COD (more than 3 g/l).

Why install anaerobic treatment in a PCP wastewater treatment plant?It is a very interesting process in terms of operating costs as no aeration is required. In addition, organic pollution

is partly converted into biogas that may be used to generate electricity. The biogas is principally made up of methane and carbon dioxide.

What are the options for anaerobic treatment of PCP wastewaters?Even though anaerobic treatment offers many advantages, it is, however, not often employed for PCP wastewater treatment for the following reasons:anaerobic biodegradability (as a rule, anaerobic bacteria are more sensitive to toxins than aerobic bacteria), economical feasibility due to small daily volumes of PCP wastewater, potential formation of siloxanes in the biogas when silicones are present in wastewater, etc.As such, the feasibility of anaerobic treatment for PCP wastewaters is considered case by case.

B.9 EvapoconcentrationWhat is evapoconcentration?The evapoconcentration (or evapocondensation) is a method of concentrating a solution by boiling the more volatile solvent, typically water. This process consists of evaporation (passage from liquid phase to vapor phase) followed by condensation of the vapor (passage of gas phase to liquid phase).

PCPWastewater

Biogas(Methane + CO₂)

Nutrients

New cells(Biomass)

TreatedWastewater


Evaporator

EnergyDistillate

Wastewater feedConcentrate

Why install evapoconcentration in a PCP wastewater treatment plant ?This process is used to reduce the volume of wastewater prior to disposal (the concentrate) while producing a high quality condensate, which in some cases may be recycled or reused, contributing to Zero Liquid Discharge objectives. Evapoconcentration may also be used to recover bi-products from the effluent.

APPLICATIONS FOR PCP WASTEWATER

What are the results of evapoconcentration?The evapoconcentration will separate the wastewater into 5-10% of concentrate and 95-90% of condensate. The concentrate contains the pollutants having a boiling temperature higher than water (metals, ions, oils) while the condensate contains mostly water and products having a boiling temperature lower than water.

Expected pollution reduction in the condensate• Very good reduction of COD and BOD• Almost total elimination of minerals and metals ~90-

98%• Micropollutants: removal according to molecular

weight and temperature applied

B.10 Tertiary TreatmentWhat is tertiary treatment?Tertiary treatment is one (or several) additional treatment step(s) after the biological treatment (secondary treatment). It improves wastewater quality before it is reused, recycled or discharged to the environment.

A variety of processes exist: • Polishing: microfiltration, ultrafiltration (UF), multi-me-

dia filtration (MMF)• Micropollutants removal: processes involving activated

carbon (e.g. clarifier + activated carbon), reverse osmosis (RO), advanced oxidation processes (e.g.Fenton for color removal), granular activated carbon filter (GAC filter),...

• Disinfection tools : ultraviolet, oxidation (by chlorine)

Why install tertiary treatment in a PCP wastewater treatment plant?Tertiary treatment is employed to meet water quality expectations in the case of water containing difficult to treat pollutants. Many companies today have sustainability targets for water. Water treatment specialists work to reduce water usage by optimizing applications and apply

appropriate tertiary treatment to allow for the reuse of wastewater where possible. Several solutions can be considered: site water recycling; cascade recycling at the point of use or Zero Liquid Discharge (ZLD).Some examples of where water may be reused: use within the wastewater treatment plant for the preparation/dilution of water treatment chemicals, rinsing

Diagram of an evapoconcentration installation

For effluent containing Typical application

Extremely high COD( >30-50 000 mg/l)

Non-biodegradable CODHair dye manufacturing

Presence of metals, ions, hardness Make-up products

For relatively low daily flowrate 5-50 m/d

Diagram of a Reverse Osmosis skid

Diagram of a Activated carbon Filter


Diagram of a centrifuge decanter

waters, use within the production facility, cooling tower make-up, boiler feed make-up, rinsing, cleaning or use in and around the site for irrigation.The choice of treatment line will depend on the incoming water quality, the reuse applications, the site configuration and the local legislation.

B.11- Sludge treatment, waste and by-products disposalWhat is sludge treatment?Sludge refers to the residual, semi-solid material that is produced as a by-product of wastewater treatment.In most cases, sludge originates from:• The primary separation (usually coagulation-

flocculation-DAF)• The biological treatment, e.g. directly from the MBR or

from the secondary separation in case of MBBR. • The tertiary treatment, if one exists

Why install sludge treatment in a PCP wastewater treatment plant?Sludge treatment technologies aim to:• Minimize the volume to be discharged by removing water• Facilitate transportation, handling and storage by

improving the sludge’s texture

What types of treatment are suitable for PCP sludges and what are the results?The technologies used for sludge treatment include: centrifuge decanter, volute dewatering press or filter press. Conditioning of the sludge prior to dewatering is required.

Centrifuge decanter A centrifuge decanter is often proposed because of low capital expenditure compared to the other technologies. A centrifuge decanter aims to obtain the pasty state of sludge (a sort of "cake") in a short space of time. Using centrifuge decanter technology, the expected dryness of the cake is within the range of 15 to 25% DS (Dry Solid).

Volute dewatering press It is another dewatering technology which gives good results. It is structured with a filter element that consists of two types of rings: a fixed ring and a moving ring -

a screw that thrusts the filter element, transfers and pressurizes the sludge. The gaps between the rings and the screw pitch get narrower towards the sludge cake outlet, which thickens and dewaters the sludge.Using this technology on a mix of sludges coming from DAF (oily) and biological sludge, the expected dryness of the cake is within the range of 20 to 25% dry solids (DS). Due to the principle of separation (no centrifuge force), no issue with foaming has been observed. The technology is reliable, easy to operate and low energy.

Filter-pressThe filter-press is a machine used to filter liquids loaded with solid matter in suspension under pressure. It is composed of 3 main parts: the frame, the filter part and the hydraulic power unit. Its operation is discontinuous. The filtration cycle can be broken down into four phases (a filling phase – a pressing phase – a compaction phase – a demounting phase) and can vary from less than half an hour to more than half a day depending on the type of sludge. A backwash cycle using pressurized water is activated every 10 to 30 pressings in order to maintain the filtration capacity.The filter cake is expected to be between 30-35% DS.

Further sludge treatmentTo reduce sludge volume even more, solutions like solar sludge drying may be of interest. Sludge drying is an operation that consists of evaporating free and bound water, following the dewatering step.Solar sludge drying is an environmentally-friendly process because it uses solar energy which is renewable and free. Because of dried sludge volume reduction, the downstream transportation cost is reduced. The dried sludge may be disposed via landfill or incineration.

Diagram of a filter-press

Diagram of a Volute dewatering press


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4. TYPICAL TREATMENT LINESThe technologies presented thus far may be combined by water treatment experts to produce a treatment line appropriate for the incoming wastewater and the discharge destination of the treated water. Below are some examples of typical treatment lines observed by Veolia Water Technologies (Veolia) along with some examples based on real-life situations.

WASTEWATER TREATMENT

EQUALIZATION TANK > DAF > MBBR > DAF

EQUALIZATION TANK > DAF > MBBR > ACTIVATED SLUDGE > CLARIFICATION

EQUALIZATION TANK > DAF > MBR

EQUALIZATION TANK > EVAPOCONCENTRATION > MBR

WASTEWATER TREATMENT FOR REUSE

EQUALIZATION TANK > DAF > MBR > GAC FILTER > RO > DISINFECTION

EQUALIZATION TANK > DAF > MBBR > DAF > DMF + GAC > RO > DISINFECTION

EQUALIZATION TANK > DAF > ACTIVATED SLUDGE > CLARIFICATION > UF > RO > DISINFECTION


A. EQUALIZATION TANK > DAF > MBBR > DAFWastewater Treatment

Manufactured products:Skin care (day cream and night cream, eye cream, face cleanser, make up remover) + hair care (sham-poo, conditioner), others.

Design capacity:300 m/d – 2.7 T/d COD – Highly concentrated ef-fluent (COD: 13 000 mg/l) – High FOG – TSS: 2100 mg/l.

Treated water requirements:COD < 800 mg/l – BOD < 500 mg/l – TSS < 400 mg/l – N-NH4 < 10 mg/l.

Discharge:Industrial estate wastewater treatment plant.

Customer needs:In addition to meeting the discharge goals, the client wanted to reduce the site’s carbon footprint. The wastewater treatment plant design also needed to accommodate for future growth in production at the site. The solution proposed was also influenced by the client's desire to complete the station in re-cord time (10 months between the start-up and the hand-over).

Treatment line:> Effluent treatmentEqualization Tank + Coagulation/Flocculation Tank + DAF + MBBR 1 + MBBR 2 + Flocculation + DAF

> Sludge treatment: > Storage and mixing tank + Dewatering on a centri-fuge decanter.

How does the plant respond to the challenges?> Compliance with environmental standards: • Due to high FOG content in the wastewater, the

DAF was chosen as primary treatment and has pro-ven to be effective. A coagulation-flocculation step prior to the DAF aids with the removal of FOG and TSS in the DAF. As the COD/BOD ratio is around 2.5, the effluent is biodegradable and as partial orga-nic matter removal is required, an MBBR process in two tanks is ideal.

• The plant removes 95% of COD and 95 % of TSS, exceeding the client’s requirements

> Reduction of footprint and carbon emission: • By minimizing land use and construction: DAF flo-

tation and MBBR are both compact technologies;

• Reduction of waste: dewatered sludge may be used as an alternative material in cement produc-tion (by certified third parties);

• As with other biological aerobic processes, ener-gy consumption is mainly due to aeration and the MBBR’s consumption is comparable to a conven-tional activated sludge plant.

> Flexibility for a future extension:The choice of MBBR offers flexibility: it is possible to increase biological capacity by adding carriers in the MBBR tanks, extend the pure MBBR by adding an ac-tivated sludge tank, etc...

> Speed of deploymentAll processing structures are made of steel, including the biological tanks, which is quicker to implement. The compact design of the MBBR process makes it possible.

Added value of the solution> Robustness of the biological process: the first MBBR tank can buffer the influent quality variations and thus protect the second MBBR tank, ensuring stable overall performance

> Easy operation and easy maintenance : no recircu-lation of sludge – no sludge bulking problems in the MBBR.

Equalization Tank DAFDAF MBBR


B. EQUALIZATION TANK > DAF > MBBR > ACTIVATED SLUDGE > CLARIFICATIONWastewater Treatment

Manufactured products:Foundation, skin care, mascara

Design capacity:300 m/d – COD extremely variable: average 9000 mg/l and peak 16 000 mg/l – FOG: 350 mg/l – TSS: 5300 mg/l

Treated water requirements:COD < 500 mg/l – BOD < 100 mg/l – TSS < 400 mg/l – N-NH4 < 100 mg/l

Discharge:Pretreatment for future re-use

Customer needs:The challenge was to ensure a thorough and safe treatment of the variable quality of the effluent, while optimizing the reuse of existing structures.

Treatment line:> Effluent treatmentEqualization Tank + Coagulation/Flocculation Tank + DAF + MBBR + Activated Sludge Tank (AS) + Seconda-ry clarifier

> Sludge treatment: Storage and mixing tank + dewatering on volute dewatering press.

How does the plant respond to the challenges?> Compliance with a high level of environmental standards: • Removal of the pollution: due to FOG content in

the wastewater, a DAF was chosen as the primary treatment and has shown to be effective. A coa-gulation-flocculation step prior to DAF facilitates removal of FOG and TSS in the DAF.

• Because of the high level of treated water re-quested, the MBBR + Activated Sludge (AS) confi-guration was chosen. The two-step biological treatment allows the development of selective biomass: • In the MBBR tank, the biomass will degrade the

easily biodegradable compounds. Additionally, the MBBR tank will act as a buffering tank prior to the activated sludge tank

• In the activated sludge, the biomass will remove the slowly biodegradable COD thanks to the long retention time (HRT)

The performance of the whole treatment line en-sures a global removal rate of 97-98% of COD and 99% of TSS.

> Reduction of carbon emissions: • Low footprint: DAF flotation and MBBR are both

compact technologies• By producing less biological sludge compared to

CAS

Added value of the solution• Robustness of the biological process: The process

is stable and the start-up and restart process is fas-ter than with conventional activated sludge.

• Easy operation: the biological sludge has better settling quality than that produced by conventio-nal activated sludge process and therefore there is less risk of bulking in the secondary clarifier.

Equalization Tank

DAF

Secondary Clarifier

MBBR

Activated Sludge Tank


C. EQUALIZATION TANK > DAF > MBRWastewater Treatment

Manufactured products:Skin care products

Design capacity:350 m/d – 0.75 T/d COD – Concentrated effluent (COD: 4000 mg/l average). Part of the wastewater comes from domestic sewage.

Treated water requirements:COD < 125 mg/l – BOD5 < 10 mg/l – TSS < 10 mg/l - Escherichia Coli < 100 u/100ml

Discharge:To river

Customer needs:The client needed to obtain a very high quality level of treated water based not only on COD and TSS pa-rameters but also on bacteriological parameters, all while ensuring a compact footprint.

Solution:MBR provides advanced biological treatment for the elimination of COD, BOD, TSS and obtains a signifi-cant reduction in microbiological contamination. Due to its compact size, the installation has a small footprint.

Treatment line:> Effluent treatment:Rotating screen 0.75 mm + Equalization Tank + Floc-culation + DAF + MBR

> Sludge treatment: Grease Storage + Dewatering using a centrifuge de-canter.

How does the plant respond to the challenges?> Compliance with the stringent discharge limits: • A rotating screen is placed upstream of the DAF.

The DAF ensures the removal of TSS, FOG and part of COD (including silicon). The MBR allows for the total elimination of TSS and removal of COD down to refractory COD. The MBR, acting as a physical barrier, also removes some of the bacterial pollution.

• Compared to other biological treatments, the removal of COD is maximized with the MBR as the aged sludge allows for the removal of slowly biodegradable COD. In addition, due to the membrane separation, which retains all suspended matter, all corresponding COD is also retained by the membrane.

• The performance of the whole treatment line results in a global removal rate of 97% of COD, 98% of TSS and 4-5 log of Total Coliforms.

> Compact size of the installation: • A biological step with MBR is usually 2-3 times

smaller than a conventional activated sludge because of the high applied load and the absence of a secondary clarifier.

Added value of the solution> Separation of the sludge:

The concentration of sludge in the biological tank is high, thus allowing for its treatment directly after dewatering and without thickening.

> Operational reliability: • No suspended solids can escape due to the

membrane barrier• Good resistance of the biomass to toxic products• High tolerance to effluent quality variations

> Flexibility for future upgrading:If water reuse is required the plant can easily be extended with, for example, granular activated carbon filtration and reverse osmosis.

Equalization Tank DAF MBR


D. EQUALIZATION TANK > EVAPOCONCENTRATION > MBRWastewater Treatment

Manufactured products:Soap and shampoo

Design capacity:30 m/d – 1 T/d COD – Highly concentrated effluent (COD: 35 000 mg/l) - High concentration of surfac-tants (30 000 mg/l)

Condensate quality requirements:COD < 1500 mg/l – Conductivity < 50 µS/cm

Condensate discharge:To the existing MBR installation

Concentrate qualityCOD > 250 000 mg/lConductivity > 40 000 µs/cmChlorides < 10 000 mg/l

Customer needs: Having an existing wastewater plant with MBR, the client wanted to be able to treat this effluent stream containing detergent used for cleaning the mixing tanks with the existing MBR installation. However these effluents were concentrated and too loaded with surfactants to be treated directly with the exis-ting biological treatment.

Treatment line: > Effluent treatment:Equalization Tank + Evapoconcentration + MBR on condensate

> Concentrate disposal: to external incineration

How does the plant respond to the challenges?> Compliance with the feed quality required by the MBR:

• Reduction of the pollution: the evapoconcen-tration process results in the separation of the condensate and the concentrate. The reduction in COD and BOD in the condensate is such that the condensate quality is sufficiently good to be sent directly to the MBR.

> Reduction of waste: • The waste to be incinerated is the concentrate.

Its volume is 15% of the initial volume of wastewater. Therefore the disposal cost is reduced.

Added value of the solution• Reduced footprint through minimized land use

and construction: evapo-concentration and MBR are both compact technologies

• Flexibility for future extension: facilitated by standardized and modular evapoconcentration units

Equalization Tank

Evapo-concentration MBR


E. EQUALIZATION TANK > DAF > MBR > GAC FILTER > RO > DISINFECTIONWastewater Treatment for Reuse

Manufactured products:Skin care (body care, face care, shower gel), hair care (shampoo, conditioner), hair dye, deodorant

Design capacity:100 m/d – 0.75 T/d COD – Highly concentrated ef-fluent (COD: 7250 mg/l) – Medium biodegradabi-lity (COD/BOD: 2.4) – High FOG: 800 mg/l – TKN: 70 mg/l

Treated water requirements:COD < 15 mg/l – Oxidability (KMnO4) < 5 mg/l – Tur-bidity < 5 NTU – TN < 50 mg/l – N-NH4 < 15 mg/l – Uncolored – Colony count < 100 CFU/ml

Discharge: Reuse on site of treated water for cleaning and coo-ling purposes.

Customer needs: The client wanted to reduce water consumption on its manufacturing site and therefore asked for a treatment line producing water suitable for reuse applications. In addition, the space allocated for the wastewater treatment plant was limited.

Treatment line: > Effluent treatment:Rotating screen 0.75 mm + Equalization Tank + Coa-gulation-Flocculation + DAF + Intermediate Tank + MBR + GAC Filter + RO Double pass + Disinfection

How does the plant respond to the challenges?> Production of treated water for reuse in the context of a reduced footprint: • DAF combined with MBR for biological treatment

in a highly compact solution.• The granular activated carbon treatment stage

ensures the removal of elements that could foul the reverse osmosis membranes: refractory COD that wasn’t removed by the biological treatment, coloring agents, silicon, surfactants...

• The reverse osmosis membranes remove residual soluble refractory COD and dissolved salts.

The performance of the whole treatment line re-sults in a removal rate of 99.9 % of COD, 100% of TSS

and 95% of dissolved salts, thus ensuring that the water meets the standards for reuse on site.

> Compact design of the installation: • All the technologies are compact, which reduces

the overall footprint of the installation.

Added value of the solutionThis solution results in a very high quality of water while at the same time minimizing the treatment stages when compared to other treatment lines (CAS, MBBR, etc.) In fact, the MBR solution combines biological treatment and membrane filtration. This gives an advantage in terms of investment cost and ease of operation.

Equalization Tank DAF RO DisinfectionMBR GAC Filter


F. EQUALIZATION TANK > DAF > MBBR > DAF > DMF + GAC > RO > DISINFECTION Wastewater Treatment for Reuse

G. ACTIVATED SLUDGE > SECONDARY CLARIFIER > UF > RO > DISINFECTIONWastewater Treatment for Reuse

EqualizationTank DAF DAF RO DisinfectionMBBR DMF +

GAC Filter

EqualizationTank

ActivatedSludge TankDAF Secondary

clarifier RO DisinfectionUF

• The Dual Media Filters (DMF) remove the remaining suspended solids present in the water at the outlet of the secondary DAF.

• With Ultrafiltration + Reverse Osmosis

• The existing conventional activated sludge was enhanced through the addition of ultrafiltration and reverse osmosis to allow for reuse.

Other examples of treatment lines for reuseMany combinations of processes are possible for building a treatment line for re-use. The choice of the most suitable treatment will depend on the wastewater quality, the reuse purposes, the type of projects (greenfield/ upgrade...), and the available tanks if any.


AOP Advanced Oxidation Process: process which removes organic materials by oxidation through reactions with hydroxyl radicals (OH)

BOD₅ Biochemical (or biological) Oxygen Demand in 5 days (mg/l).BOD is the amount of oxygen necessary for degradation of organic materials present in the effluent by the action of microorganisms. BOD₅ is expressed in milligrams of oxygen consu-med per liter of sample during 5 days of incubation at 20 °C.

CAS Conventional Activated Sludge (including clarifier)

COD Chemical Oxygen Demand (mg/l). COD is an index of the pollution, mainly organic, in an effluent. It evaluates the amount of oxygen needed to oxidize the pollutant load.

CFU Colony-Forming Unit : in microbiology, a CFU is a unit used to estimate the number of viable bacteria or fungal cells in a sample

DAF Dissolved Air Flotation

EPS Extracellular Polymeric Substance: EPS are natural polymers secreted by microorganisms into their environment. These compounds are important in biofilm formation and cells attach-ment to surfaces.

EQ Equalization (tank or key process)

FENTON Fenton reagent process is one of the AOP, used for refractory COD removal. It is based on a reaction with hydrogen peroxide catalyzed by iron Fe2+.

Hardness Total hardness (TH) is the sum of the ions calcium [Ca2+] and magnesium [Mg2+].

HRT Hydraulic Retention Time : HRT is a measure of the average length of time that the com-pound remains in a tank

Micelle An aggregate of molecules in a colloidal solution, such as those formed by detergents.

5. GLOSSARY


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Veolia Water Technologies

L’Aquarène • 1 place Montgolfier • 94417 Saint-Maurice Cedex • Francetél. 01 45 11 55 55 - fax 01 45 11 55 50www.veoliawatertechnologies.com

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