Abstract:
The remediation of soil contaminated with petrochemicals using conventional methods
is very di cult because of the complex emulsions formed by solids, oil, and water. Electrokinetic
remediation has of recent shown promising potential in the removal of organics from contaminated
media as calls for further improvement of the technology are still made. This work investigated the
performance of electrokinetic remediation of soil contaminated with petrochemicals by applying fixed
electrode configurations and continuous approaching electrode configurations. This was done in
combination with bioremediation by inoculating hydrocarbon degrading bacteria and biosurfactants
with the aim of obtaining an improved method of remediation. The results obtained show that the
biosurfactant produced by the hydrocarbon degrading bacteria Pseudomonas aeruginosa was able to
enhance oil extraction to 74.72 2.87%, 57.375 3.75%, and 46.2 4.39% for 185 mm fixed electrodes,
335-260-185 mm continuous approaching electrodes, and 335 mm fixed electrode configurations,
respectively. By maintaining high current flow, the 335-260-185mmcontinuous approaching electrodes
configuration enhanced electroosmotic flow (EOF) on every event of electrodes movement. The fixed
electrode configuration of 185 mm provided amiable pH conditions for bacterial growth by allowing
quick neutrality of the pH due to high EOF as compared to the 335 mm fixed electrodes configuration.
After 240 h, the carbon content in the soil was reduced from 0.428 0.11 mg of carbon/mg of the
soil to 0.103 0.005, 0.11355 0.0006, and 0.1309 0.004 for 185 mm, 335-260-185 mm, and 335 mm,
respectively. The application of biosurfactants and continuous approaching electrodes reduced the
energy expenditure of electrokinetic remediation by enhancing the decontamination process with
respect to time.
