Fenton oxidation and combined Fenton-microbial treatment for remediation of crude oil contaminated soil in Assam – India

Abstract

The study is aimed at the remediation of soil spiked with crude oil (5%) by employing Fenton oxidation, biological treatment and combined Fenton-biological treatment. A spiked concentration of 5% crude oil was selected on the basis of contamination levels of 0–5% as found in the soil of upper Assam oil fields (India). The degradation of the aliphatic fraction (C₁₄–C₂₈) of the crude oil was investigated by gas chromatography. Fenton oxidation was carried out at different pH (3 to 8) in a laboratory batch reactor and maximum oxidative degradation was observed at pH 3–5. At pH 3, single Fenton oxidation resulted in 36 and 57% degradation in 5 and 10 days respectively. Biological treatment (with Fusarium solani) and combined Fenton-biological treatment were carried out with a one month incubation period. Biological treatment alone brought about 61% degradation of the crude oil while the combined process could achieve as much as 75% degradation of the aliphatic fractions of the crude oil.