Remediation of TCE-contaminated water by enhanced chemical oxidation using Na2S2O8/H2O2/red mud

Abstract

In this study, the feasibility of degrading trichloroethylene (TCE)-contaminated water (initial TCE concentration of approximately 45 mg/L) was evaluated via persulfate oxidation activated by red mud. The study indicates that red mud is able to activate the persulfate oxidation mechanism producing sulfate radicals (SO4-⋅) to oxidize TCE. There is a higher TCE removal (92%) with the addition of 2 g/L red mud after 5 h of oxidation reaction vs. non red mud system (42% TCE removal). A maximum TCE removal efficiency is obtained at neutrality condition. The TCE degradation rate reached 95% at lower temperature with the oxidation of hydrogen peroxide and sodium persulfate, respectively. This result reveals that the ability of activated persulfate (S2O82-) to generate sulfate radicals (SO4-⋅) is limited by thermal. In addition, a favorable TCE degradation rate is acquired for Fenton-like oxidation reaction with hydrogen peroxide and sodium persulfate as oxidant.