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 (H2O2). In the anode chamber, a new solar-light-driven system was devised using chloride ions (Cl-) as a medium and WO3 photoanode as a radical initiator. Under solar light irradiation, photogenerated holes yielded at the WO3 photoanode promoted the conversion of Cl- to reactive chlorine species, which could oxidize BPA more rapidly. The results indicated that the SPA 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 CO2 and H2O in 120 min. In the cathode chamber, a new dopamine modified carbon felt (CF-DPA) cathode was employed to produce H2O2, 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 H2O2 yields. (C) 2019 Elsevier Ltd. All rights reserved.