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.

A Critical Review of the Modelling Tools for the Reactive Transport of Organic Contaminants

“…Looking at the articles from the last decades, one might conclude that some studies will continue to be site-specific, focusing on high-risk sites [47,48], large-scale sites [48][49][50][51][52], or areas with extreme conditions [53][54][55][56][57]. Certainly, some articles will refer to laboratory experiments and the dynamics of reactions affecting the attenuation of hydrocarbons in soils and water [58][59][60]. When it comes to studying the fate of hydrocarbons in the subsurface, there is still room for mesoscale laboratory studies [61][62][63] or field experiments [64-67], as these types of studies better reflect the ongoing processes in heterogeneous soils and the growth of bacterial communities in the quasi-real environment.…”