Improved electrochemical oxidative degradation of Reactive Red 24 dye by BDD anodes coupled with nitrate: operating parameters, kinetics, and degradation pathways

Abstract

The electrochemical oxidation (EO) process coupled with BDD anode and nitrate was used to improve Reactive Red 24 (RR24) removal efficiency in wastewater treatment. The effects of operating parameters on the decolorization efficiency of RR24 were discussed, and the optimal operating parameters were obtained as follows: 45 mA cm− 2, 100 mM SO42−, 7 mM NO3−, 60°C, pH 5.88, and 100 mg L− 1 RR24 initial concentration. The energy consumption for 100% decolorization within 15 min is 0.92 kWh m− 3, and the total organic carbon (TOC) reaches 51.35% within 90 min. Through the effect of quenchers on RR24 decolorization efficiency, various active species in the EO process were studied. It was found that •OH was closely related to the decolorization degradation of RR24, reaching a contribution rate of 99.47%. Finally, we propose the degradation pathways of RR24 by UV-Vis spectrum and LC-MS test. In summary, the proposed treatment process could be applied to treat RR24 dyes as an efficient method.