remediation of oil contaminated soils: a reviewpsrcentre.org/images/extraimages/34 414042.pdffig. 7...

Abstract—Petroleum exploration, production, transportation and application can adversely affect the environment. Leakages from

pipelines, oil wells, underground storage tanks, improper disposal of petroleum wastes and soil spills are the major sources of surface and groundwater contamination. These hydrocarbons have to be removed from the soil for environmental and health reasons as well as avoiding further contamination of surface and groundwater. Various methods are available to achieve soil habilitation. The performance of these methods depends on several factors such as amount of oil spill, oil penetration depth into the soil, soil type and as well as age and

level of contamination. This study reviews various oil contaminated remediation methods such as extraction with organic solvents, extraction with aqueous solution, subcritical fluid extraction and bioremediation with bacteria.

Keywords—Contamination, environment, extraction, habilitation,

petroleum.

I. INTRODUCTION

IL production and shipping operations result in accidental

contamination of soil with petroleum hydrocarbons.

Petroleum refining also results in the generation of large

quantities of oil sludge consisting of hydrophobic substances

and substances resistant to biodegradation. Soil oil

contamination also result from fuel storage tank leakages,

crude oil spill sand refinery waste disposal. The soil near

railroad junctions usually becomes oil contaminated because

the railroad industry uses diesel oil for fuel, lubricating oil for

machinery, and waste-lubricating oil on the railroad. Such

sites often contain organic contaminants including benzene,

toluene, ethylbenzene, and petroleum hydrocarbons (PHCs)

[1].

Contamination of soils by these PHCs poses a major

environmental problem, especially to the soil environment,

and has caused serious health problems [2]. PHCs are highly

toxic and carcinogenic substances, often produced by

incomplete combustion of carbon compounds [3]. Their

solubility in pure water is low [4], and they are strongly

adsorbed in soils, especially onto terrestrial colloids. Also,

Motshumi Joseph Diphare is with the Department of Chemical

Engineering, Faculty of Engineering and the Built Environment, University of

Johannesburg, Doornfontein, Johannesburg 2028, (email:

[email protected]).

Edison. Muzenda is a full Professor of Chemical Engineering, is with the

Department of Chemical Engineering, Faculty of Engineering and the Built

Environment, University of Johannesburg, Doornfontein, Johannesburg 2028,

South Africa, Tel: +27115596817, Fax: +27115596430, (Email:

[email protected]).

small amounts of heteroatom like nitrogen and sulphur, as

well as trace amounts of metals like vanadium and nickel are

found in oil contaminated soil [5]. Meanwhile, the world demand for fuel has led to the

exploration and production of an increasing number of

petroleum hydrocarbon reserves. Therefore it is very

important to recover these scarce and valuable hydrocarbons

while protecting the environment. There is also an increasing

demand for development of soil remediation technologies that

are cost effective and sustainable [6]. It is essential to

regenerate the soil to support animal and plant life, and also

guard against long-term health threats to humans and other

species. References [7]-[11] studied various cost effective and

sustainable soil remediation technologies to regenerate oil

contaminated land. These methods include surfactant

solubilisation, solvent extraction, supercritical fluid extraction,

hot water extraction, and various other leaching remediation

techniques.

Onsite incineration has been mostly used as the cheapest

process for remediating contaminated soil, but negative public

opinion and perception towards incineration has led to the

consideration of other treatment options. Remediating oil

contaminated sites could provide more land for housing

development which is a challenge for developing countries

due to population growth and diminishing residential land

[12]. This can also make land available for agricultural

activities increasing food.

Solvent extraction complemented with bioremediation is an

attractive approach as bioremediation has the ability to

inexpensively treat a wide range of organics in all

environmental media, generating little or no residues with a

low carbon footprint, and causing minimal, if any, ecological

effects [13]. The objective of this study is to highlight the importance of

oil contaminated soil remediation, review the various

treatment options paying attention on their application and

limitations.

II. REVIEW OF VARIOUS REMEDIATION TECHNOLOGIES

A. Soil Washing with Organic Solvents

Solvent extraction can be utilized to efficiently remove

hydrophobic organic contaminants from soils [14]. References

[15, 16] reported solvent extraction efficiencies between 75

and 99%. Reference [7] studied the extraction of

pentachlorophenol from soils contaminated with wood treating

Remediation of Oil Contaminated Soils:

A Review

Motshumi Diphare and Edison Muzenda

O

Intl' Conf. on Chemical, Integrated Waste Management & Environmental Engineering (ICCIWEE'2014) April 15-16, 2014 Johannesburg

180

wastes using ethanol–water mixture and reported over 86%

removal of pentachlorophenol from the soil. Reference [16]

showed that 5:1 alkane–alcohol solvents can effectively

remove the majority of polychlorinated dibenzo-p-dioxins and

polynuclear aromatic hydrocarbons from soils. Reference [17]

removed 75% of chlorinated compounds and hydrocarbons in

the diesel range from soil using ethyl acetate–acetone–water

mixtures.

Reference [5] studied the regeneration of heavy crude oil

contaminated soils using hexane - actone solvent mixture. A

similar procedure as in [7] was followed. Fig. 1 shows the

schematic diagrams for 3 stage crosscurrent and counter

current solvent extraction process.

Fig. 1 Three-stage (a) crosscurrent and (b) counter current solvent

extraction process [5].

The oil pollutants were grouped into four major classes,

saturates (S), naphthene aromatics (NA), polar aromatics

(PA), and asphaltenes (A). Reference [5] reported no

significant changes in the removal of (S) with acetone content

variation in the mixture from 0 to 0.75 mole fraction ratio. The

removal of NA increased with increasing acetone content up

to 0.25 volume fraction. PA removal also increased with the

increasing acetone volume fraction, Fig. 2. The reference [18]

reported that the dissolving capacity of the solvent increases

with the increase polarity similarity with the oil pollutants.

Fig. 2 Extraction oil from soils using hexane–acetone solvent

mixture [5]

The increase in solvent-to-soil ratio enhances the interaction

between the oil contaminants solvent and also increases the

concentration gradients between liquid–solid phases. 60 and

90% of A, and S, NA as well PA were respectively removed at

solvent – soil ration of 6 to 1, Fig. 3.

Fig. 3 Contaminants removed at different solvent soil ratio [5]

B. Soil Washing with Aqueous Solutions

Soil washing is a promising remediation technique because

in addition to treating oil contaminated soil it has the potential

to remove heavy metals from soli as well [19]. Surfactants are

added to counter the low aqueous solubility of PAHs and

enhance soil washing with water [20]. Surfactants enhance the

solubility of PAHs in water by partitioning these molecules

into the hydrophobic cores of surfactant micelles [21]. Also,

the presence of surfactant micelles decreases surface and

interfacial tensions [22]. Reference [23] surfactants

drawbacks. Such as adsorption into the soil and the prevention

of micelles efficient circulation in soil. Therefore it is

necessary to sieve before bubbling into the soil – solution

mixture.

Reference [24] studied the washing of phenanthrene

contaminated soil with four non-ionic surfactants, Tween 40,

Tween 80, Brij 30 and Brij 35. Brij 30 removed 84.1% of

phenanthrene at a surfactant concentration of 2 g/l. This can be

attributed to the phenanthrene dissolution ability of Brij 30

and its low adsorption onto soil.


181

Fig. 4 Experimental set-up used for the regeneration of an aqueous

solution of bpm CD, (a) Liquid-liquid extraction and (b)

ultrafiltration [25]

Reference [25] reported the decontamination of soil

polluted with phenanthrene and pyrene by re-using aqueous

solutions of methyl-b-cyclodextrin (bpm CD), Fig. 4.

Fig. 5 Extraction efficiency from contaminated soil by bpm CD [25]

The variation of PAHs removal with bpmCD concentration

is shown in Fig. 5. Phenanthrene was completely removed

while a 60% removal was achieved for pyrene.

Reference [25] also reported the influence of bpmCD

circulation on PAHs removal, Fig. 6. 30 and 70% recovery of

pyrene and phenanthrene respectively was achieved after 2

days of slow re-circulation

Fig. 6 Effect of recirculation time on extraction of PAHs [25]

C. Extraction with Subcritical Water

The subcritical fluid is held in its liquid state and

maintained below its critical point under high pressure and

temperature. Subcritical water extraction (SCWE) also known

as pressurised hot water extraction uses water heated from 100

◦C to 274 ◦C under pressure to maintain it in its liquid form

[20]. The superheated and pressurised water is used as a

solvent instead of organic chemicals. As the temperature is

raised, the hydrogen bonding network of water molecules

weakens resulting in a lower dielectric constant and

simultaneously decreasing its polarity. Thus, subcritical water

becomes more hydrophobic and organic-like than ambient

water, promoting miscibility of light hydrocarbons with water

[26]. Reference [27] performed pilot plant studies focused on

the removal of PAHs from soil The optimum subcritical water

extraction was reported to be at 275oC. Fertility studies of the

remediated soil showed that it was healthy with positive

germination and earthworm toxicity curbed to zero percent.

Reference [28] studied subcritical water treatment of PAHs

contaminated sand at varying temperatures. Recoveries of

around 80% were reported irrespective of extraction time with

the exception of naphthalene with a reduction in recovery of

about 35% when the extraction time was increased from 1 to

20 hours.

Oily lubricating materials were effectively removed from

lubricating machine parts using SCWE at relatively low

temperatures [29]. Reference [30] also used SCWE to

remediate PHCs contaminated soils. Lab-scale SCWE set – up

for this process is shown in Fig. 7.

Reference [30] studied the influence of temperature and

time on the SCWE of lubricating oil from contaminated soil.

Extraction efficiency was found to be temperature dependent,

Fig. 8.

This was attributed to the decreased dielectric constant and

surface tension of subcritical water with increase in

temperature allowing for significant dissolution of nonpolar

organic compounds in water. The recovery of lubricating oil

from contaminated soil was also reported to time dependent,

Fig. 9.


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Fig. 7 Subcritical water extraction apparatus [30]

Fig. 8 Effect of temperature on the extraction of lubricating oil

[30]

Fig. 9 The effect of time on extraction of lubricating oil [30]

D. Bioremediation with Bacteria

Biodegradation is the natural recycling wastes by breaking

down organic or inorganic matter into nutrients using living

organisms under aerobic or anaerobic conditions. Reference

[20] reported the application of onsite techniques such as land

farming, composting and soil piles as well the use of advanced

ex situ methods such as bioreactors with better control of

temperature and pressure to enhance the degradation of PAHs

in soil. Aerobic bacteria use oxygen as an electron acceptor to

break down both the organic and inorganic matters into

smaller compounds, often producing carbon dioxide and water

as final products [31]. Due to the absence of suitable

endogenous microbial population and incompatible

environment conditions, PAHs are naturally more resistant to

biodegradation and remain in the environment for years.

Hence, ex situ bioremediation techniques utilizes PAH

specific exogenous microorganisms such as bacteria and fungi

[32]. Reference [33] reported the successful degradation of 16

priority PAHs using the injection of bacteria, fungi and

bacteria – fungi microbial groups. Two white rot fingi were

reported to achieve 58 -73% degradation of 3- and 4 – ring

PAHs. Aerobic conditions and specific micro-organisms are

required for the bioremediation of PAHs contaminated soils.

The soil oxygen content is influenced by microbial activity,

soil texture as well as water content and depth [35]. Thus,

aerobic conditions and appropriate micro-organisms are

necessary for an optimal rate of bioremediation of soils

contaminated with PAHs. The oxygen content in soils depends

on microbial activity, soil texture, water content and depth

[35]. Low oxygen content was found to limit the

bioremediation of PAHs contaminated soils [36].

Reference [37] enhanced the remediation of oil sludge

contaminated soil using bacterial consortium, inorganic

supplements, bulking agents and compost [37]. The process

was optimized as in Table 1. TABLE 1

EXPERIMENTAL CONDITIONS

Experiment Treatment Conditions

1 Soil + oil sludge (abiotic control)

2 Soil + oil sludge

3 Soil + oil sludge + compost

4 Soil + oil sludge + bacterial consortium

5 Soil + oil sludge + inorganic nutrients +

bacterial consortium

6 Soil + oil sludge + wheat bran +

bacterial consortium

Inorganic nutrients was found to produce little influence on

oil removal compared to soil amendment without inorganic

nutrients. Soil microbial population was found to enhance the

removal of hydrocarbons from soil. Organic compost was

found not significantly enhance the removal of hydrocarbons

from soil compared to the set-up with inorganic nutrients

(66% oil degradation). This showed the absence of

hydrocarbon degrading strains in the compost.

III. CONCLUSION

Various oil contaminated soil remediation techniques exist.

The removal efficiency is influenced by oil type, soil type,

weather conditions, penetration depth, sensitivity of the

location and the toxicity of the chemicals. To date, no method

has been reported to be able to completely remove oil from

contaminated sites. Hence the first option is avoidance of oil


183

spillages and leakages. However, in the case of spillages or

leakages, urgent and quick actions are required to minimize

the environmental impact.

ACKNOWLEDGMENT

The authors are grateful to the National Research

Foundation of South Africa (NRF), and the Council of

Scientific and Industrial Research (CSIR) for providing

bursaries to the first author. The department of Chemical

Engineering at the University of Johannesburg is

acknowledged for funding the research as well as conference

attendance.

REFERENCES

[1] T. Badr, K. Hanna, C. De Brauer, “Enhanced solubilisation and removal

of naphtalene and phenanthrene by cyclodextrins from two contaminated

soils,” J. Hazard. Mater, vol. 112, pp. 215–223, 2004.

[2] K. Urum, T. Pekdemir, “Evaluation of biosurfactants for crude oil

contaminated soil washing,” Chemosphere, vol. 57, pp. 1139–1150,

2004.

[3] V. Andreoni, L. Gianfreda, “Bioremediation and monitoring of aromatic

polluted habitats, Appl. Microbiol. Biotechnol, vol. 76, pp. 287–308,

2007.

[4] D. McKay, W. Y. Shiu, K. C. Ma, “Illustrated Handbook of Physical–

Chemical Properties and Environmental Fate for Organic Chemicals,”

Lewis Publishers, 2002.

[5] L. Xingang, D. Yongliang, W. Guozhong, L. Zhongyuan, L. Hong, S.

Hong, “Solvent extraction for heavy crude oil removal from

contaminated soils,” Chemosphere, vol. 88, pp. 245–249, 2012.

[6] G. Z. Wu, F. Coulon, Y. W. Yang, H. Li, H. Sui, “Combining solvent

extraction and bioremediation for removing weathered petroleum from

contaminated soil,” Pedosphere, vol. 23(4), pp. 455–463, 2013.

[7] A. P. Khodadoust, M.T. Suidan, C. M. Acheson, R. C. Brenner, “Solvent

extraction of pentachlorophenol from contaminated soils using water

ethanol mixtures, Chemosphere, vol. 38, pp. 2681–2693, 1999.

[8] I.F. Paterson, B. Z. Chowdhry, S. A. Leharne, “Polycyclic aromatic

hydrocarbon extraction from a coal tar contaminated soil using aqueous

solutions of nonionic surfactants, Chemosphere, vol. 38, pp. 3095–3107,

1999.

[9] T.J. Smyth, R. G. Zytner, W. H. Stiver, “Influence of water on the

supercritical fluid extraction of naphthalene from soil,” J. Hazard.

Mater., vol 67, pp. 183–196, 1999.

[10] S. B. Hawthorne, C. B. Grabanski, “Correlating selective supercritical

fluid extraction with bioremediation behaviour of PAHs in a field

treatment plot,” Environ. Sci. Technol., vol. 34, pp. 4103–4110, 2000.

[11] A. Dadkhah, A. Akgerman, “Hot water extraction with in situ wet

oxidation: PAHs removal from soil,” J. Hazard. Mater., vol. 93, pp.

307–320, 2002.

[12] Government of the Northwest Territories, “Environmental Guideline for

Contaminated Site Remediation,” Yellowknife, NWT, November 2003

[13] R. M. Atlas, C. E. Cerniglia, “Bioremediation of petroleum pollutants,”

Bioscience, vol. 45, 332–338, 1995.

[14] F. Murena, F, Gioia, “Solvent extraction of chlorinated compounds from

soils and hydrodechlorination of the extract phase,” J. Hazard. Mater,

vol. 162, pp. 661–667, 2009.

[15] C. Dumitran, I. Onutu, F. Dinu, “Extraction of hydrophobic organic

compounds from soils contaminated with crude oil,” Rev. Chim, vol. 60,

pp. 1224–1227, 2009.

[16] P. Nam, S. Kapila, Q. H. Liu, W. Tumiatti, A. Porciani, V. Flanigan,.

“Solvent extraction and tandem dechlorination for decontamination of

soil,” Chemosphere, vol. 43, pp. 485–491, 2001.

[17] A. Silva, C. Delerue-Matos, A. Fiuza, “Use of solvent extraction to

remediate soils contaminated with hydrocarbons, J. Hazard. Mater., vol.

124, pp. 224–229, 2005.

[18] C. M. Hansen, “Hansen Solubility Parameters: A User’s Handbook,”

second ed. CRC Press, Boca Raton, 2007.

[19] S.K. Samanta, O.V. Singh, R.K. Jain, “Polycyclic aromatic

hydrocarbons: environmental pollution and bioremediation,” Trends

Biotechnol., vol. 20 (6), pp. 243–248, 2002.

[20] S. Gan, E. V. Lau, H. K. Ng, “Remediation of soils contaminated with

polycyclic aromatic hydrocarbons (PAHs),” J. Hazard Mater., vol. 172,

pp. 532-549, 2009.

[21] J.-L. Li, B.-H. Chen, “Solubilization of model polycyclic aromatic

hydrocarbons by non-ionic surfactants, Chem. Eng. Sci., vol. 57, pp.

2825–2835, 2002.

[22] C.N. Mulligan, R.N. Yong, B.F. Gibbs, “Surfactant-enhanced

remediation of contaminated soil: a review,” Eng. Geol., vol. 60, pp.

371–380, 2001.

[23] C. Candida, C.C. West, J. H. Harwell, “Surfactants and subsurface

remediation,” Environ. Sci. Technol., vol. 26, pp. 2324–2330, 1992.

[24] C.K. Ahn, Y.M. Kim, S.H. Woo, J.M. Park, “Soil washing using various

non-ionic surfactants and their recovery by selective adsorption with

activated carbon,” J. Hazard. Mater., vol. 154, pp. 153–160, 2008.

[25] A. Petitgirard, M. Djehiche, J. Persello, P. Fievet, N. Fatin-Rouge,

“PAH contaminated soil remediation by reusing an aqueous solution of

cyclodextrins,” Chemosphere, vol. 75, 714-718, 2009.

[26] J. Kronholm, J. Kalpala, K. Hartonen, M.-L. Riekkola, “Pressurized hot

water extraction coupled with supercritical water oxidation in

remediation of sand and soil containing PAHs,” J. Supercrit. Fluids, vol.

23 pp. 123–134, 2002.

[27] A. J. M. Lagadec, D. J. Miller, A.V. Lilke, S. B. Hawthorne, “Pilot-scale

subcritical water remediation of polycyclic aromatic hydrocarbon- and

pesticide contaminated soil,” Environ. Sci. Technol., vol. 34 pp. 1542–

1548, 2000.

[28] J. Kronholm, T. Kuosmanen, K. Hartonen, M. L. Riekkola, “Destruction

of PAHs from soil by using pressurized hot water extraction coupled

with supercritical water oxidation,” Waste Manage., vol. 23, pp. 253–

260, 2003.

[29] H. Kim, J. Kweon, “Cleaning of lubricating products from machinery

parts using subcritical water,” KSCE J. Civ. Eng., vol. 14, pp. 1–6, 2010.

[30] M. N. Islam, Y. T. Jo, J. H. Park, “Remediation of soil contaminated

with lubricating oil by extraction using subcritical water,” J. Ind. Eng.

Chem., Article in press, 2013.

[31] D. Aronson, M. Citra, K. Shuler, H. Printup, P. H. Howard, “Aerobic

biodegration of organic chemicals in environmental media: A summary

of field and laboratory studies, Environmental Science Center, New

York, 2008.

[32] A. Mrozik, Z. Piotrowska-Seget, S. Labuzek, “Bacterial Degradation

and Bioremediation of Polycyclic Aromatic Hydrocarborns,” Polish

Journal of Environmental Studies, vol. 12, No. 1, pp. 15-25, 2003.

[33] X. Li, P. Li, X. Lin, C. Zhang, Q. Li, Z. Gong, “Biodegradation of aged

polycyclic aromatic hydrocarbons (PAHs) by microbial consortia in soil

and slurry phases,” J. Hazard. Mater., vol. 150, pp. 21–26, 2008.

[34] V. Leonardi, V. Saˇsek, M. Petruccioli, A. D Annibale, P. Erbanova, T.

Cajthaml, “Bioavailability modification and fungal biodegradation of

PAHs in aged industrial soils,” Int. Biodeterior. Biodegrad., vol. 60, pp.

165–170, 2007.

[35] A. L. Juhasz, R. Naidu, Bioremediation of high molecular weight

polycyclic aromactic hydrocarbons: a review of the microbial

degradation of benzo[a]pyrene, International Biodeterioration &

Biodegradation 45, pp. 57-88, 2000.

[36] R. T. von Wedel, S. F. Mosquera, C. D. Goldsmith, G. R. Hater, A.

Wong, T. A. Fox, W. T. Hunt, M. S. Paules, J. M. Quiros, J. W.

Wiegand, “Bacterial biodegradation of petroleum hydrocarbons in

ground water: in situ augumented bioreclamation with enrichment

isolates in California. Water Sci Technol., vol. 20, pp. 501-503, 1988.

[37] N. Vasudevan, P. Rajaram, “Bioremidiation of oil sludge-contaminated

soil,” Environment International, vol. 26, pp. 409-411, 2001.

Motshumi Diphare is a Masters student in Chemical

Engineering at the University of Johannesburg. Mr.

Diphare holds a Bachelor degree in Chemical

Engineering. He is a recipient of several awards and

scholarships for academic excellence. His research

interests are in waste recycling particularly waste

lubricants and hydrocarbons, waste-to-energy and the

environment. He has contributed to 8 international peer

reviewed and refereed scientific articles. He has co-

supervised 6 BTech research students. He is currently serving as the President

of Chemical Engineering Student Association at the University of

Johannesburg.


184

Edison Muzenda is a Full Professor of Chemical

Engineering, the Research and Postgraduate

Coordinator as well as Head of the Environmental and

Process Systems Engineering Research Group in the

Department of Chemical Engineering at the University

of Johannesburg. Professor Muzenda holds a BSc

Hons (ZIM, 1994) and a PhD in Chemical Engineering

(Birmingham, 2000). He has more than 15 years’

experience in academia which he gained at different Institutions: National

University of Science and Technology, University of Birmingham,

Bulawayo Polytechnic, University of Witwatersrand, University of South

Africa and the University of Johannesburg. Through his academic

preparation and career, Edison has held several management and leadership

positions such as member of the student representative council, research

group leader, university committees’ member, staff qualification

coordinator as well as research and postgraduate coordinator. Edison’s

teaching interests and experience are in unit operations, multi-stage

separation processes, environmental engineering, chemical engineering

thermodynamics, entrepreneurship skills, professional engineering skills,

research methodology as well as process economics, management and

optimization. He is a recipient of several awards and scholarships for

academic excellence. His research interests are in green energy engineering,

integrated waste management, volatile organic compounds abatement and

as well as phase equilibrium measurement and computation. He has

published more than 180 international peer reviewed and refereed scientific

articles in journals, conferences and books. Edison has supervised 28

postgraduate students, 4 postdoctoral fellows as well as more than 140

Honours and BTech research students. He serves as reviewer for a number

of reputable international conferences and journals. Edison is a member of

the Faculty of Engineering and Built Environment Research and Process,

Energy and Environmental Technology Committees. He has also chaired

several sessions at International Conferences. Edison is an associate

member of the Institution of Chemical Engineers (AMIChemE), member of

the International Association of Engineers (IAENG); associate member of

Water Institute of Southern Africa (WISA), Associate Editor for the South

African Journal of Chemical Engineering as well as a member of the

Scientific Technical Committees and Editorial Boards of several scientific

organizations.


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