Electrochemical degradation of bromophenol blue on porous PbO2–ZrO2 composite electrodes

Abstract

The electrochemical performance of porous PbO2–ZrO2 composite electrode was studied with bromophenol blue (BPB) as the simulated pollutant. In the process of electrochemical degradation, the operational parameters were optimized, such as initial BPB concentration, current density, initial pH values and supporting electrolyte (Na2SO4) concentration. The results showed that the BPB and COD removal efficiency could reach 96.9% and 74.7%, respectively, after 90 min of electrolysis under the degradation parameters of initial BPB concentration of 30 mg L−1, current density of 40 mA cm−2, pH value of 4 and Na2SO4 solution of 0.07 mol L−1. The kinetic curves made clear that the electrochemical degradation of BPB followed pseudo-first-order reaction with high correlation coefficients (R2 > 0.99). Initial BPB concentration and applied current density greatly affected the electrochemical process, followed by the pH value, and the influence of supporting electrolyte was minimal. Ultraviolet–visible spectra and high-performance liquid chromatography analysis indicated that a small amount of intermediates were produced during the degradation process. After electrochemical degradation for 90 min, BPB and intermediates were almost completely removed. In terms of multiple aspects, electrochemical degradation had a good development prospect in the treatment of BPB wastewater.