阳极接触辉光放电电解法降解水中C_(4)~C_(8)全氟羧酸  

Degradation of C_(4)-C_(8)perfluorocarboxylic acids(PFCAs)in aqueous solution by anodic contact glow discharge electrolysis

作　　者：于彻 张超 李佳骏 高荣荣 温晓 尹凤超 杨海明[1] YU Che;ZHANG Chao;LI Jiajun;GAO Rongrong;WEN Xiao;YIN Fengchao;YANG Haiming(School of Chemical Engineering,University of Science and Technology Liaoning,Anshan 114051,China;Anshan Ecological Environment Bureau,Anshan 114000,China)

机构地区：[1]辽宁科技大学化学工程学院,辽宁鞍山114051 [2]鞍山市生态环境局,辽宁鞍山114000

出　　处：《化工环保》2022年第4期421-427,共7页Environmental Protection of Chemical Industry

基　　金：国家自然科学基金青年基金项目(51308276);辽宁科技大学创新团队项目(2017TD02);辽宁科技大学青年骨干计划项目(601011507-18);辽宁省教育厅项目(2020LNJC06)。

摘　　要：采用阳极接触辉光放电电解(ACGDE)法降解水中C_(4)~C_(8)全氟羧酸(PFCAs),考察了PFCAs降解反应的影响因素、反应动力学和反应机理。结果表明,ACGDE可将全氟辛酸(PFOA)等PFCAs降解,240 min后,PFOA的去除率可达90.0%,脱氟率可达38.2%。随着PFCAs碳链的变短,ACGDE对PFCAs的降解效果变差。溶液pH升高和有机污染物吡啶的存在均有利于PFOA降解。引发PFOA降解的主要活性物质是H·/水合电子。PFCAs的降解和脱氟过程均符合准一级反应动力学。PFOA降解过程中的主要中间产物为其他短链PFCAs,降解机理主要是e_(aq-)攻击C—F键对其进行脱氟降解,生成碳链更短的PFCAs。短碳链PFCAs降解是PFOA降解的控制步骤。An anodic contact glow discharge electrolysis(ACGDE)process was adopted for degrading C_(4)-C_(8)perfluorocarboxylic acids(PFCAs)in aqueous solution.The factors,kinetics and mechanism of PFCAs degradation were investigated.The results show that PFCAs such as perfluorooctanoic acid(PFOA)can be degraded by ACGDE,the removal rate of PFOA reaches 90%and the defluronation rate reaches 38.2%after 240 min of reaction.The degradation effect of PFCAs by ACGDE is reduced with the shortening of carbon chains of PFCAs.The increase of solution pH and the presence of organic pollutants such as pyridine are beneficial for PFOA degradation.It is found that H·/hydrate electron(e_(aq-))is the main active substance triggering the PFOA degradation.The degradation and defluronation of PFCAs are all in accordance with the first-order kinetics.The main intermediates in PFOA degradation are other PFCAs with shorter chains,and the main degradation mechanism is that the defluorination and degradation are triggered by e_(aq-)attacking C—F bond to generate PFCAs with shorter carbon chains.The degradations of PFCAs with shorter carbon chains are the key steps for PFOA degradation.

关 键 词：全氟辛酸 阳极接触辉光放电电解 还原 脱氟 

分 类 号：X703.1[环境科学与工程—环境工程]