Ethanol Cosolvent Concentration Effects on Remediation Efficiency, Index Properties, and Compaction Characteristics of Electrokinetic-Remediated Crude Oil-Contaminated Lateritic Soil

John E. Sani, Alexander Joseph, George Moses, Barakat O. Ochu, Faustinus Bayang, Alhassan Abdulaziz

Abstract


Crude oil spillage along pipeline corridors severely degrades the geotechnical integrity of lateritic soils in sub-Saharan Africa, rendering them unfit for road sub-base and subgrade applications. Electrokinetic remediation (EKR), enhanced with organic cosolvents, offers a promising in-situ strategy for decontaminating these soils. This study investigated the effects of ethanol cosolvent molar concentrations (0, 0.05, 0.10, 0.15, and 0.20 mol/L) on the remediation efficiency (total petroleum hydrocarbon removal), index properties (Atterberg limits, specific gravity, and particle size distribution), and compaction characteristics (maximum dry density and optimum moisture content) of crude oil-contaminated lateritic soil subjected to EKR. Crude oil-contaminated soil was collected at 1 m depth from the Nigerian Pipeline and Storage Company site in Kaduna. EKR was conducted in a Plexiglas cell at 1 V/cm potential gradient with ethanol cosolvents buffered with 0.01 M NaOH at the anode. Laboratory tests followed BS 1377 (1990) protocols. TPH removal efficiency increased consistently with cosolvent concentration, reaching optimum performance at 0.20 mol/L. Liquid limit declined from 50% to 19%, plastic limit from 25.0% to 15.3%, and plasticity index from 25.6% to 3.7% as cosolvent concentration increased. Specific gravity improved from 2.61 to 2.73. Maximum dry density rose from 1.66 Mg/m³ (BSL) to 1.89 Mg/m³ (BSH), while optimum moisture content decreased from 14.46% to 10.63%. Ethanol-enhanced EKR at 0.20 mol/L significantly restores the geotechnical suitability of crude oil-contaminated lateritic soils, meeting the Nigerian General Specifications for Roads and Bridges (2016) requirements for sub-base materials. 


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References


Al-Qaisee, G. S., Mohammed, A. R., & Mahdi, E. M. (2020). Black oil leakage influence on the physical and engineering properties of Faw soil. Journal of Southwest Jiaotong University, 55(2), 1–8. https://doi.org/10.35741/issn.0258-2724.55.2.14

Cho, K., Myung, E., Kim, H., Purev, O., Park, C., & Choi, N. (2020). Removal of total petroleum hydrocarbons from contaminated soil through microwave irradiation. International Journal of Environmental Research and Public Health, 17(16), 5952. https://doi.org/10.3390/ijerph17165952

Choi, B., Lee, S., & Jho, E. H. (2020). Removal of TPH, UCM, PAHs, and Alk-PAHs in oil-contaminated soil by thermal desorption. Applied Biological Chemistry, 63, 83–89. https://doi.org/10.1186/s13765-020-00569-3

Federal Ministry of Works. (2016). Nigerian general specification for roads and bridges (Revised edition). Federal Ministry of Works, Abuja.

Haruna, B. I., Adebayo, K., Sani, J. E., Moses, G., & Ibrahim, S. I. (2023). Effect of ethanol and acetone cosolvents in enhancing electrokinetic remediation of crude oil contaminated soil obtained from a pipeline and storage company, Kaduna, Nigeria. Journal of Applied Sciences and Environmental Management, 27(5), 933–937. https://doi.org/10.4314/jasem.v27i5.2

Karthigeyan, S., & Ramachandran, A. (2020). Physical and engineering properties of oil contaminated clay soil. International Journal of Engineering Research & Technology (IJERT), 9(5), 763–766. https://doi.org/10.17577/IJERTV9IS050436

Maturi, K., & Reddy, K. R. (2008). Cosolvent-enhanced desorption and transport of heavy metals and organic contaminants in soil during electrokinetic remediation. Water, Air, & Soil Pollution, 189(1–4), 199–211. https://doi.org/10.1007/s11270-007-9568-9

Meshari, S. A. (2021). Determination of total petroleum hydrocarbons (TPHs) in weathered oil contaminated soil. Environmental Engineering Research, 27(5), 210324. https://doi.org/10.4491/eer.2021.324

Oyediran, I. A., & Enya, N. I. (2021). Crude oil effects on some engineering properties of sandy alluvial soil. International Journal of Mining and Geo-Engineering, 55(1), 7–10. https://doi.org/10.22059/ijmge.2019.286060.594808

Salimnezhad, A., Soltani-Jigheh, H., & Soorki, A. A. (2021). Effects of oil contamination and bioremediation on geotechnical properties of highly plastic clayey soil. Journal of Rock Mechanics and Geotechnical Engineering, 13(3), 653–670. https://doi.org/10.1016/j.jrmge.2020.11.005

Soltani-Jigheh, H., Molamamhmood, H. V., Ebadi, T., & Soorki, A. A. (2018). Effects of oil-degrading bacteria on geotechnical properties of crude-oil contaminated sand. Environmental and Engineering Geoscience, 24(3), 333–341. https://doi.org/10.2113/EEG-1948

Streche, C., Cocârţă, D. M., Istrate, I., & Badea, A. A. (2018). Decontamination of petroleum contaminated soils using the electrochemical technique: Remediation degree and energy consumption. Scientific Reports, 8(1), 272–285. https://doi.org/10.1038/s41598-018-21606-4

Suleiman, A., Salim, I. M., Timothy, A. A., Abdulrahman, H., Yusuf, B. A., & Sadi, I. H. (2020). Effect of crude oil spillage on engineering properties of tropical residual soil. IOP Conference Series: Earth and Environmental Science, 476, 012048. https://doi.org/10.1088/1755-1315/476/1/012048

Yue, S., Jie, M., Gangsen, Y., Shuyu, L., Hanyu, L., Quanwei, S., & Baichun, W. (2021). Comparisons of four methods for measuring total petroleum hydrocarbons and short-term weathering effects in soils contaminated by crude oil and fuel oils. Water, Air, & Soil Pollution, 232(381). https://doi.org/10.1007/s11270-021-05341-7.


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