LAUSR

Abstract Simultaneous electrosynthesis of H 2 O 2 and persulfate was performed in a paired electrolysis system separated by a cationic membrane. To maximize the current efficiency, H 2 O 2 reacted in-situ with the added ferrous ion to form Fenton's reagent, while persulfate was used for commercial production. In the processing of electrolytic procedure, sulfate ion consumed constantly became the limiting factor for producing persulfate, while H 2 SO 4 and KSCN did not. Cyclic voltammetry test and radical quenching experiments were carried out to validate the electrosynthetic route of persulfate. During the electro-Fenton process, H 2 O 2 was decomposed into hydroxyl radical by either the added ferric ion or electron transfer reaction which resulted in a rapid degradation of phenol. The area ratio of anthode surface to anode surface was optimized to be 10:1. During the coupling process, various catholyte conditions had negligible effect on anodic electro-generation of persulfate. However, in the anode compartment the pattern was different. Hydrogen ion (H 2 SO 4 ) both in the anolyte and in the catholyte had an extensively negative effect on cathodic electrosynthesis of H 2 O 2 . Eventually, optimum conditions for the cathodic indirect oxidation of organic pollutant paired to anodic persulfate production were optimized. The coupling process can be considered as an alternative and efficient method for maximizing the utilization of the electrochemical technology.