The Influence of Soil and Organic Matter on Trichloroethylene Decomposition by Fenton Reaction

Abstract

Contamination of soil and ground water by trichloroethylene (TCE) has become a serious problem in recent times. Fenton reaction can be used for the chemical decomposition of polluting substances. In this study, Fenton reagent was used as an in situ oxidizing agent for soils contaminated with TCE. We investigated the kinetics of TCE decomposition by Fenton reaction involving Fe(II). The results of our experiments show that the rates of TCE decomposition in the presence of all soils except Toyoura sand are lower than that in the absence of soils. TCE decomposition by Fenton’s reaction with Fe(II) in the presence and absence of black soil was found to be of the first order to concentrations of TCE and Fe(II) and half-order to hydrogen peroxide concentration. The reaction rate constants in the presence and absence of black soil were determined to be 1.048 and 0.568 (L·mol–1)1.5·s–1, respectively. Assuming the reaction order to be 2.5, the reaction rate constants in the presence of humic acid, Kanuma soil, Toyoura sand, and akadama soil were determined to be 0.849, 0.725, 1.050, and 0.354 (L·mol–1)1.5·s–1, respectively. The decrease in the rate is speculated to be affected by both specific surface area and carbon content of the soil.