Effect of anions on the removal of bisphenol A in wastewater by electro-oxidation process

Bisphenol A (BPA), an endocrine-disrupting chemical, exists widely in natural waters. Advanced oxidation processes, which are based on the generation of hydroxyl radicals (⋅OH), are one of the promising techniques for the treatment of BPA. The goal of the present study was to investigate the effect of nitrate, bicarbonate, and carbonate in wastewater treatment plant (WWTP) effluent on the removal of bisphenol A (BPA) by bench-scale electro oxidation (EO) process using DSA-Ti electrode. The removal efficiency of BPA against scavenger effect of nitrate and alkalinity was characterized under a variety of reaction time and current densities. In the current density of 3 mA/cm2, the BPA removal efficiencies showed 40% within 20 min in the presence of nitrate, whereas the BPA removal efficiency was close to 100% in the absence of nitrate. Under the same condition, 42 and 80% of BPA was removed in the presence of bicarbonate and carbonate, respectively. The results indicated that the EO process is a promising technology to remove BPA effectively in WWTPS. However, since the efficiencies of the EO process were remarkably reduced when the concentrations of anions in WWTPs increased, electrochemical technology such as EO process could be used only to oxidize the non-biodegradable compounds during the WWTP process.