Electrochemical oxidation of Reactive Blue 19 on boron-doped diamond anode with different supporting electrolyte

Abstract

• BDD-PS EAOP was used to treat RB-19 simulated dye wastewater. • Persulfate electrolyte has excellent temperature adaptability. • BDD-PS system can degrade organics efficiently with low energy consumption. • BDD-PS system can effectively degrade wastewater in a wide pH range (1.5-12). In this study, boron-doped diamond film (BDD) electrode with high sp 3 /sp 2 ratio was prepared by hot filament chemical vapor deposition (HFCVD). A systemic electrochemical advanced oxidation processes (EAOPs) study was carried out by using BDD anode and three different supporting electrolyte (Na 2 SO 4 , NaCl, and Na 2 S 2 O 8 ) to degrade the high volume and high concentration (0.5 L, 100 mg L -1 ) simulated anthraquinone Reactive Blue 19 (RB-19) dye wastewater. BDD-PS (persulfate) system was used to study the effects of current density, initial pH and solution temperature on decolorization degree and mineralization rate (TOC removal rate) by comparing with other two electrolytes (NaCl and Na 2 SO 4 ). BDD activated PS could effectively degrade RB-19 in a large pH range (1.5-12), and higher degradation efficiency and lower energy consumption under strong acid and alkali conditions than traditional BDD-EO based on Na 2 SO 4 and NaCl electrolytes. More interestingly, at the temperature of 70 ℃, the TOC removal reached 90% in 30 min and 100% in 60 min, which is apparently higher than that under NaCl and Na 2 SO 4 as electrolytes. Our work indicates BDD-PS technology can effectively degrade organic wastewater, which has the characteristics of efficiently and better pH applicability, and more importantly which can decompose RB-19 with the aid of increase of temperature.