Fenton Pre-Oxidation Followed by Microbial Degradation for Removing Crude Oil from Contaminated Soil

Through the Fenton pre-oxidation followed by microbial degradation, this study gave full play to its advantages while avoiding its shortcomings for the remediation of crude oil contaminated soil. The Fenton reagent coupled with different volumes of H2O2 was applied to the oil contaminated soil and then the microbial agents were introduced to biodegrade the re-sidual oil for 15 days. The correlation between the characteristics of residual oil in soil, the changes in soil physical-chemical property after the Fenton pre-oxidation, and the biodegradation were analyzed in this paper. The results show that the above factors are strongly correlated with the subsequent biodegradation rate, and the order of correlation is as follows: the ratio of TOC to NH4+-N (R2 = 0.9513) > the ratio of light oil components to the heavy oil components (R2 = 0.9095) > the proportion of hydrocarbons with carbon chain number of less than C23 (R2 = 0.8259) > the crude oil content (R2 = 0.7603) > the soil pH (R2 = 0.7492) > the number of microorganisms (R2 = 0.6506). During the biodegradation and pre-oxidation reactions of heavy oil components, an appropriate C:N ratio turns out to be the most critical factor in this study.