Chemical oxidation of hydrocarbon-contaminated soil: oxidant comparison study and soil influencing factors

Abstract

The objective of this research is to investigate Fenton reaction, permanganate and persulfate oxidation as in-situ remediation technology for the treatment of gasoline-diesel contaminated soil. These oxidants were compared in various soils to study the influence of soil texture and soil organic matter. The different fractions of hydrocarbons, which have been scarcely investigated, were also analyzed and the compounds were clustered into aliphatic and aromatic hydrocarbons. Maximal removal rates were obtained with permanganate (74%), followed by persulfate (60%) and hydrogen peroxide (55%). High levels of clay in the soil (silty clay soil) reduced the efficiency of permanganate and persulfate hydrocarbon oxidation by 18%. On the other hand, 5% soil organic matter decreased the effectiveness of permanganate (18%). The removal rates of hydrocarbons decreased while hydrocarbon size increased, and aromatic hydrocarbons were more oxidized than aliphatic ones. In general, elimination percentages higher than 80% are achieved for chains >C6-C8 and lower than 20% for those in the range >C21-C35.The results observed can be used to increase the efficiency and improve the design of advanced oxidation processes for treating gasoline and diesel contaminated soil.