Electrokinetic Removal of Petroleum Hydrocarbon from Residual Clayey Soil Following a Washing Process |
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Authors: | Chil‐Sung Jeon Jung‐Seok Yang Kyung‐Jo Kim Kitae Baek |
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Institution: | 1. Greenviro Co. Ltd., DaeSong, Pohang, Gyeongbuk, Republic of Korea.;2. KIST‐Gangneung Institute, Gangneung, Republic of Korea.;3. Department of Environmental Engineering, Kumoh National Institute of Technology, Gyeongbuk, Republic of Korea. |
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Abstract: | This study investigates total petroleum hydrocarbon (TPH) removal from residual clayey soil, after a washing procedure, using an electrokinetic process. Eight electrokinetic experiments were carried out to investigate the characteristics of TPH removal. When 0.1 M MgSO4 or 0.1 M NaOH was used as an electrolyte, the electric current rapidly increased within the first 100 or 200 h, respectively. A negatively charged soil surface resulted in a more negative zeta potential and greater electroosmotic flow toward the cathode. Therefore, the accumulated electroosmotic flow (EOF) when using 0.1 M NaOH as the anolyte‐purging solution was higher than when using 0.1 M MgSO4. Although the energy consumption for the two purging solutions was similar, the efficiencies of TPH removal when 0.1 M MgSO4 and 0.1 M NaOH with surfactant were used were 0 and 39%, respectively, because the electroosmotic flow rate increased with TPH removal efficiency. When 5% isopropyl alcohol (IPA) was used as a circulation solution, the electric current increased but the TPH removal was similar to that using water. In terms of energy consumption, the use of a surfactant‐enhanced electrokinetic process with NaOH as electrolyte was effective in removing TPHs from low‐permeability soil. |
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Keywords: | Electrokinetic Electrolyte Electroosmosis Surfactant Total petroleum hydrocarbon |
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