Electrochemical treatments of coking wastewater and coal gasification wastewater with Ti/Ti4O7 and Ti/RuO2-IrO2 anodes.J Environ Manage. 2020 Jul 01; 265:110571.JE
Electrochemical treatments of coking wastewater (CW) and coal gasification wastewater (CGW) were conducted with Ti/Ti4O7 and Ti/RuO2-IrO2 anodes. The performances of Ti/Ti4O7 and Ti/RuO2-IrO2 anodes were investigated by analyzing the effects of five key influencing factors including anodes material, current density, anode-cathode distance, initial pH value, and electrolyte type. The removal efficiencies of total organic carbon (TOC) were analyzed during the processes of CW and CGW electro-oxidation. The removal efficiencies of sixteen polynuclear aromatic hydrocarbons (PAHs) in CW and CGW by electro-oxidation were also explored to further assess the electrochemical activities of Ti/Ti4O7 and Ti/RuO2-IrO2 anodes. The Ti/Ti4O7 anode achieved 78.7% COD removal efficiency of CW, 85.8% COD removal efficiency of CGW, 50.3% TOC removal efficiency of CW, and 54.8% TOC removal efficiency of CGW, higher than the Ti/RuO2-IrO2 anode (76.7%, 78.1%, 44.8% and 46.8%). The COD removal efficiencies increased with the applied current density, decreased with the increase of the anode-cathode distance, and slightly decreased with the increase of the initial pH value. Meanwhile, the removal efficiencies of sixteen PAHs by the Ti/Ti4O7 anode were mostly higher than those by the Ti/RuO2-IrO2 anode. By comprehensively analyzing the performances of Ti/Ti4O7 and Ti/RuO2-IrO2 anodes on electrochemical treatments of CW and CGW, this study may supply insights into the application potentials of these anodes to the electrochemical treatments of real wastewater.