CaO2-based electro-Fenton-oxidation of 1,2-dichloroethane in groundwater

It has been well recognized that the Fenton reaction requires a rigorous pH control and suffers from the fast self-degradation of H 2 O 2 . In an effort to resolve the technical demerits of the conventional Fenton reaction, particular concern on the use of CaO 2 -based Fenton reaction was paid in this study. To realize the practical use of CaO 2 in the Fenton reaction for groundwater remediation, it could be of great importance to control its reaction rate in the subsurface. As such, this study laid great emphasis on the combined process of electrochemical oxidation and CaO 2 -based Fenton oxidation, using 1,2-dichloroethane (1,2-DCA) as a model compound. It was hypothesized that the reaction rate is also highly contingent on the formation of Fe(II) (stemmed from iron anode oxidation). Eighty percent of 1,2-DCA were degraded by the CaO 2 -based Fenton reaction. The final pH was neutral, inferring that the reaction could be a viable option for the subsurface environment. Moreover, the supply of electric current in an iron anode expedited 1,2-DCA degradation efficiency from 35 % to 62 % via electrically generated Fe(II), which donated electrons to H 2 O 2 , producing more hydroxyl radicals. An anode-cathode configuration from the single-well system enhanced the degradation of 1,2-DCA, with less amount of energy consumption than the double-well system. Based on results, CaO 2 -based electro-Fenton oxidation can remove well 1,2-DCA in groundwater and can be a strategic measure for groundwater remediation. • The CaO 2 -based Fenton reaction oxidized 80 % of the 1,2-DCA. • The final pH of the system was neutral, producing minimal adverse effects. • The applied current to the iron anode promoted degradation of 1,2-DCA. • A single-well system with an anode-cathode configuration was optimal. • Increased electrical current density enhanced the 1,2-DCA oxidation rate.