Enhanced photoelectrocatalytic degradation of bisphenol A and simultaneous production of hydrogen peroxide in saline wastewater treatment

The degradation of organic pollutants in saline wastewater has been a challenge for environmental remediation. In this study, a two-chamber cell was structured to simultaneously degrade organic contaminants (bisphenol A, BPA) from saline wastewater and produce hydrogen peroxide (H 2 O 2 ). In the anode chamber, a new solar-light-driven system was devised using chloride ions (Cl‾) as a medium and WO 3 photoanode as a radical initiator. Under solar light irradiation, photogenerated holes yielded at the WO 3 photoanode promoted the conversion of Cl‾ to reactive chlorine species, which could oxidize BPA more rapidly. The results indicated that the BPA removal can be significantly enhanced by increasing pH to 10.8 or increasing the Cl‾ concentration to 200 mM. At these conditions, 92% BPA was degraded into CO 2 and H 2 O in 120 min. In the cathode chamber, a new dopamine modified carbon felt (CF-DPA) cathode was employed to produce H 2 O 2 , obtaining a high concentration of 5.4 mM under optimum conditions. The electrochemical analyses for CF-DPA revealed that dopamine modification promoted electron transfer and enhanced the two-electron oxygen reduction to increase H 2 O 2 yields.