聚四氟乙烯改性掺硼金刚石电极强化降解阿特拉津  

Boron-doped diamond electrode modified by polytetrafluoroethylene to enhance the degradation of atrazine

作　　者：丁嘉 李钰 官宝红[1] DING Jia;LI Yu;GUAN Baohong(College of Environmental and Resource Sciences,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学环境与资源学院,杭州310058

出　　处：《浙江大学学报（农业与生命科学版）》2022年第3期369-376,共8页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家重点研发计划项目(2019YFC0408802)。

摘　　要：阿特拉津(atrazine,ATZ)是使用最广泛的除草剂之一,其对地表水和地下水的污染引起了人们的担忧,相关水体净化技术的研发迫在眉睫。掺硼金刚石(boron-doped diamond,BDD)电极具有羟自由基(·OH)产率高的优点,但·OH囿于电极表面,导致有机污染物的降解受到较大的限制。本研究采用聚四氟乙烯(polytetrafluoroethylene,PTFE)改性BDD电极,用于强化水中ATZ的降解。在NaCl溶液中,BDD电极经过5.0%、8.6%、20.0%PTFE分散液改性后,ATZ降解的准一级动力学常数分别提高了98.9%、88.2%和78.6%;在NaHCO_(3)和Na_(2)SO_(4)溶液中,BDD电极经8.6%PTFE分散液改性后,ATZ降解的动力学常数分别提高了49.2%和127.0%。PTFE以膜的形式附着于BDD电极表面,提高了电极电流,且黏附在电极表面的气泡有利于·OH生成并扩散到溶液本体中。BDD电极经5.0%、8.6%、20.0%PTFE改性后,溶液本体中·OH浓度分别提高了17.73倍、19.89倍和18.81倍,进而增强了对ATZ的降解速率和去除效果。PTFE改性BDD电极降解ATZ的途径主要为脱烷基、脱氯-羟基化和烷基氧化反应。Atrazine(ATZ)is one of the most popular herbicides,and the pollution of atrazine to surface water and groundwater has aroused people’s concern,which is urgent to research and develop water purification technology to deal with it.Boron-doped diamond(BDD)electrode has the advantage of highly efficient production of·OH,but the degradation of organic pollutant is seriously limited because the·OH is trapped on the surface of the electrode.In this study,BDD electrode modified by polytetrafluoroethylene(PTFE)improved the degradation efficiency of ATZ.In NaCl solution,after modification with 5.0%,8.6%and 20.0%PTFE dispersions,the quasi-first order kinetic constants of ATZ degradation reaction were improved by 98.9%,88.2%and 78.6%,respectively.In NaHCO_(3) and Na_(2)SO_(4) solutions,after modification with 8.6%PTFE dispersion,the quasi-first order kinetic constants of ATZ degradation reaction were improved by 49.2%and 127.0%.The PTFE was coated on the surface of BDD electrode in the form of film,which was beneficial to the improvement of the current.Meanwhile,the bubbles that adhered to the surface of BDD were conducive to the formation of·OH and diffusion of·OH into the homogeneous solution.The concentration of·OH in the solution bulk increased by 17.73,19.89 and 18.81 times after the modification of 5.0%,8.6%and 20.0%PTFEs,respectively,and the degradation efficiency of ATZ and removal effect were significantly enhanced.The main ways of ATZ degradation by PTFE modified BDD electrode were dealkylation,dechlorination-hydroxylation and alkyl oxidation reactions.

关 键 词：阿特拉津 掺硼金刚石电极 聚四氟乙烯 气泡 自由基 降解 

分 类 号：X592[环境科学与工程—环境工程]