Contaminated Groundwater Remediation by Catalyzed Hydrogen Peroxide and Persulfate Oxidants System

Abstract:

A binary oxidant system, catalyzed hydrogen peroxide (H₂O₂) coupled with persulfate (S₂O₈^2-), was investigated for use in in-situ chemical oxidation (ISCO) applications. Trichloroethene (TCE) and 1,4-dioxane were used as target contaminants. Batch experiments were conducted to investigate the catalytic efficiency between ferrous ion (Fe²⁺) and base (NaOH), oxidant decomposition rates, and contaminant degradation efficiency. For the base-catalyzed H₂O₂-S₂O₈^2- system, oxidant release was moderate and sustained over the entire test period of 96 hours. Conversely, the oxidants were depleted within 24 hours for the Fe²⁺-catalyzed system. Solution pH decreased slightly for the Fe²⁺-catalyzed system, whereas the pH increased for the base-catalyzed system. The rates of degradation for TCE and 1,4-dioxane are compared as a function of system conditions. The results of this study indicate that the binary H₂O₂-S₂O₈^2- oxidant system is effective for oxidation of the tested contaminants.