Treatment of 1,4-dioxane and trichloroethene co-contamination by an activated binary persulfate-peroxide oxidation process.

The efficacy of a binary oxidant system, hydrogen peroxide (H2O2) and persulfate, was investigated for treatment of 1,4-dioxane (dioxane) and trichloroethene (TCE) co-contamination. Batch experiments were conducted to examine the catalytic efficiency of Fe2+ and NaOH-based activation, oxidant decomposition rates, contaminant degradation effectiveness, and competitive degradation effects. For NaOH activation, the oxidant decomposition rate was moderate and sustained during the entire test period of 96 h. However, dioxane degradation was limited (~ 33%). Conversely, the oxidants were depleted within 24 h for the Fe2+-activated system, and dioxane degradation was complete within 4 h. The activation and radical generation processes were different between Fe2+ and NaOH activation. Both dioxane and TCE underwent complete degradation in the co-contaminant experiment. The results of this study indicate that the Fe2+-catalyzed binary hydrogen peroxide-persulfate oxidant system is effective for oxidation of the tested contaminants separately and as co-contaminants.