电化学氧化降解水中三唑酮效能与反应路径OACSCDCSTPCD

Organic pesticides such as triazolone(TDF)have environmental risks in the production and application processes,which are difficult to effectively remove by the conventional water treatment methods.The electrochemical oxidation processes have great potential to organic pesticides removal from water and wastewater,the performances of which is greatly dependent on the activity and stability of the anode materials.This study investigated the electrochemical oxidation of TDF in water over the Ti/RuO2-IrO2,Pt,and Ti4O7 anodes.The degradation and mineralization efficiencies of TDF were compared and evaluated in the electro-oxidation processes within these anodes.The effects of various reaction,including the current density,the TDF initial concentration and the initial solution pH,on the degradation kinetics of TDF were investigated.The degradation pathway of TDF electro-oxidation and the toxicities of TDF degradation intermediates were also explored.The Ti/Ti4O7 flat anode presented relatively high removal efficiencies of TDF and total organic carbon(TOC)in water compared with the Ti/RuO2-IrO2 and Pt anodes.The Ti4O7 flat and membrane anodes both showed relatively high electrochemical activity for TDF degradation and mineralization,the TDF and TOC removal efficiencies of which reached 94.5%-95.7%and 72.5%-75.5%,respectively.Achieving similar TOC removal efficiencies,the energy consumption of the Ti4O7 membrane anode was about 50%lower than that of the Ti4O7 plate anode.The TDF removal efficiencies was related to the reaction parameters including the current density,the initial TDF concentration,and the initial solution pH,which increased with the current density increasing,and decreased with the increase of the initial solution pH and the initial TDF concentration.The TDF(m/z=294.5)was gradually degraded into intermediates A(m/z=224.5)and B(m/z=103),and intermediate A(m/z=224.5)was further degraded into intermediates C(m/z=173.5)and D(m/z=86).These intermediates might be finally oxidized to inorganic compounds such as carbon dioxide and water.The TDF,A,B,C,and D were classified as toxic,harmless,harmless,harmful,and harmless compounds to aquatic organisms,respectively.The toxic TDF gradually degraded into non-toxic intermediates,which might lead to the decrease of solution toxicity.Based on the study,TDF could be efficiently degraded and mineralized by the electrochemical oxidation technology over the Ti4O7 anodes,providing reference ideas for the researches and practices on the electrochemical oxidation of organic pesticides in water and wastewater.