Bioavailability enhancement of petroleum-contaminated soil by electrokinetic remediation

Abstract

The Electro kinetic Remediation Technology (EKR) is recognized as the most potential remediation technology for soils with low permeability, like clay soil characteristics. Electrokinetic treatment could increase the bioavailability of contaminants in bioremediation petroleum-contaminated soil. The study, “Bioavailability enhancement of petroleum contaminated soil by electrokinetic remediation,” is experimental research in a laboratory to improve the bioavailability of petroleum hydrocarbons on clay during bioremediation with initial treatment using electrokinetic remediation techniques, finding optimum electrokinetic operating conditions of remediations, and analyzing the mechanism of remediation process in contaminated soil. Bioavailability enhancement was studied for 35 days. Polluted soil was treated with an electrokinetic box test (17cm×12cm×10cm), and DC power was used for 48 hours. Total Petroleum Hydrocarbon (TPH) concentration was determined by gravimetric methods. The results showed that the characteristics of the soil samples were dominated by 49.31% clay. The initial concentration of TPH in polluted soil is 3.7%. The electrokinetic applications during 48 hours and followed by bioremediation for 35 days those processes removed TPH up to 80.74 % (from 33780.66 mg HC (kg dry w)-1 to 6506.155176 mg HC (kg dry w)-1. There is an increase in bioavailability indicated by the rise in bacterial populations and an increase in biodegradation after electrokinetic remediation. With this approach, bioavailability has been increased by 70.18%. Bio-electrokinetic remediation is the recommended method for polluted clay soils with low bioavailability.