Biosurfactants as demulsification enhancers in bio-electrokinetic remediation of petroleum contaminated soil

Abstract

To remediate petroleum-contaminated soil, a DC powered electrokinetic reactor was used with amended biosurfactant concentrations of 28 g/L, 56 g/L, and 84 g/L to enhance the extraction of oil from the soil and aid in the biodegradation of the remaining oil by hydrocarbon-degrading microbes. The highest oil extraction of 83.15 ± 1.97 % was obtained with the biosurfactant concentration of 56 g/L while the highest degradation was observed when 84 g/L of biosurfactants were used. The bacteria survived the electro-halo-thermal environment and degraded the remaining hydrocarbons to as low as 0.0405 ± 0.057 mg of carbon/mg of soil when 84 g/L of biosurfactants were used. Microbial growth was however affected by the relentlessly changing pH in the reactor. The presence of biosurfactants significantly aided in oil recovery and biodegradation in the first 96 h of the experiments.