Efficient treatment of high‑concentration sulfurous wastewater by using electrochemical oxidation process with Ti/SnO_2–Sb anode and air cathode

摘要

High-concentration sulfurous wastewater is biologically toxic, corrosive, harmful to environment and human health,highly required to be separately treated. In this paper, an air–cathode electrochemical oxidation process (EO) was investigatedto treat high-concentration sulfurous wastewater from coal chemistry industry. The effectiveness was evaluatedby chemical oxygen demand (COD) removal, color (ADMI) removal, and total organic carbon (TOC) removal. The resultsshowed that 99.1% COD, 100% color, and 94.5% TOC were removed by EO at the applied current of 40 mA cm~(−2) for24 h. The COD removal accords with zero-order kinetics with a constant of 2598.3 mg L~(−1) h~(−1), while the TOC removalfollows the first-order kinetics with a constant of 0.1128 h~(−1). The highest current efficiency of 94.3 ± 0.6% and the lowestenergy consumption of 9.4 ± 0.1 kWh kg COD~(−1) were achieved when removing 98% of COD at the current density of40 mA cm~(−2). The results indicate that the air–cathode electrochemical oxidation process is feasible to efficiently treathigh-concentration sulfurous wastewater.