Electro-Biodegradation of the Oil-Contaminated Soil through Periodic Electrode Switching

Electro-bioremediation is an efficient method for removal or degradation of soil organic pollutants. Oil contaminants widely exist in many regions of the world and pose persistent risk on human health. In this study, we performed a number of experiments to examine the effectiveness of electro-bioremediation on an oil-contaminated soil in a perspex cell, where oil-degrading bacteria were present. During some experiments, periodic polarity switching was applied to provide relatively stable acid-base balance in the remediation cell. The results showed that the highest contaminant degradation efficiency (72.6%) was obtained at 1V/cm while electric polarity periodically switching for the soil with an addition of 30 mg/g oil. In contrast, the contaminant degradation efficiency was only 0.03% in the control experiments. Soil pH ranged from 6.0-6.4 and soil temperature remained at 31±0.4°C during the electrokinetic bioremediation. The study demonstrates that the electrokinetic bioremediation can pronouncedly increase the degradation of oil in soil as well as providing a steady environment for microbial activities.