Treatment of Contaminated Soils and Groundwater Using ISCO

Abstract

In situ chemical oxidation (ISCO) is a rapidly growing field for the remediation of contaminated soils and groundwater. This paper provides an overview of the four oxidation systems that are in common use for ISCO: Catalyzed H2 O2 propagations (CHP) (i.e., modified Fenton’s reagent), permanganate, ozone, and persulfate. Each of the oxidants has different characteristics; for example, CHP is a nonselective oxidizing and reducing system that is capable of degrading almost all organic contaminants and destroying dense nonaqueous phase liquids and sorbed contaminants, but it is unstable in the subsurface. In contrast, permanganate is a selective oxidant that reacts primarily with alkenes and is highly stable in groundwater. Ozone exhibits wide reactivity but is limited by mass transfer limitations and stability. Persulfate is the newest oxidant being used for ISCO; it is moderately stable in the subsurface, and appears to have widespread reactivity, but more research is needed on its chemistry in soils and gr...