Electrochemical oxidation of textile wastewater combined with 185 nm UV irradiation

The chemical oxygen demand (COD) results obtained after electrochemical oxidation and UV irradiation could hardly meet the strict discharge standard of COD for the textile waste­water after biological treatment. To further treat the textile wastewater after biological treatment, UV light at 185 nm was used in the centre of the commercial PbO2 mesh cylinder anode with the titanium cylinder cathode in a cylinder electrolyzer. Performances of electro­chemical oxidation coupled with 185 nm UV irradiation were investigated at a pilot scale under different oxidation times, current density, initial pH, and electrolyte flow rate without addition of oxidant reagents. The experimental results show that the performance of electrochemical oxidation combined with 185 nm UV irradiation is better than that of either separately applied electrochemical oxidation or 185 nm UV irradiation. 2,4-di-tert-butyl­phenol, oleamide and octadecanamide could be effectively degraded by electrochemical oxidation combined with 185 nm UV irradiation. Under optimal operating conditions, the electrochemical oxidation with 185 nm UV irradiation could reduce the COD of textile wastewater from 74.0 to 31.0 mg L-1 with the electrical consumption of 252.86 kWh per kg of degraded COD, cost of 5.78 CNY per m³ of textile wastewater, and carbon emissions of 141.10 kg CO2 per kg of degraded COD. Future research should investigate the interaction effects of variables, as well as the integration of renewable energy and broader contaminant removal capabilities.