Persulfate enhanced electrochemical oxidation of phenol with CuFe2O4/ACF (activated carbon fibers) cathode

Abstract Phenol wastewater is threatened to human living environment and should been treated carefully before discharging into the environment. For my research, electrochemical (EC) oxidation of phenol using CuFe2O4/ACF cathode and mixed metal oxide (RuO2/Ti) anodes was investigated. In order to increase the EC oxidation efficiency of phenol, persulfate (PS) was added into the EC system. Various systems including EC-1 oxidation (RuO2/Ti cathode and RuO2/Ti anode), EC-2 oxidation (ACF cathode and RuO2/Ti anode), EC-3 oxidation (ACF cathode and RuO2/Ti anode, adding CuFe2O4 particle), PS oxidation (only adding PS) and EC/PS oxidation (CuFe2O4/ACF cathode and RuO2/Ti anode, adding PS) for phenol removal were compared, and the removal efficiency of phenol was determined to be 19%, 25%, 46%, 43 and 85%, respectively. Effects of K2S2O8 concentration, current density and initial pH on the removal efficiency of phenol were analyzed. The optimal phenol removal efficiency (97%) was achieved after 60 min reaction under conditions: PS concentration of 1.00 mM, current density of 50 A/m2, and initial pH of 7.0. The generation of reactive oxidant species in solution was confirmed by the electron spin resonance technique, which was in accord with the radical quenching experiments results, indicating that oxidation of phenol was assigned to radical oxidation and non-radical oxidation processes.