摘要
水中新兴抗生素类污染物是环境工作者关注的重要问题,如何高效去除抗生素及其去除动力学是需要重点探讨的研究内容.本文以掺硼金刚石为阳极,着重研究抗生素甲氧苄啶在BDD电极上的电催化降解及动力学行为,分析降解过程中施加电流密度、溶液pH、TMP浓度、支持电解质类型和浓度对降解动力学的影响规律,根据降解过程中的中间产物,提出TMP的可能降解路径.结果表明,高电流密度加快强氧化性活性物种的产生,可促进有机物的降解,但析氧副反应的加剧降低了过程的电流效率;低溶液pH有利于强氧化性活性物种的产生,加快有机物的降解动力学;由于电催化过程受传质控制,有机物的浓度的提高有利于促进降解动力学;由于活性氯的产生,电解质中氯离子的存在可加快有机物的去除,同时支持电解质Na_(2)SO_(4)浓度对有机物的矿化影响不大.TMP在BDD电极上的可能的降解路径主要包括羟基化反应、脱甲氧基化反应、裂解和开环反应,最终实现TMP完全矿化为CO_(2)、NO_(3)^(−)和H_(2)O.
Emerging antibiotic contaminants in water are considered as an important environmental issue.How to efficiently remove the antibiotics and kinetics are of great concern and need to be discussed.Electrochemical degradation of antibiotic trimethoprim(TMP)on boron doped diamond(BDD)anode was conducted in this paper,and operating parameters including applied current density,pH,pollutant concentration and supporting electrolyte concentration on the mineralization kinetics were discussed.Moreover,the possible degradation pathway of TMP during electrochemical oxidation was also proposed based on the degradation mechanism and intermediate products.The results reveal that high current density accelerates the generation of highly oxidizing active species and promotes the degradation of TMP.However,the occurrence of oxygen evolution side reaction under high current reduces the current efficiency of the process.Low pH is favorable for the generation of highly oxidizing active species and accelerates the degradation kinetics.Due to the fact that the electrocatalytic process is controlled by mass transfer process,the increase of TMP concentration is beneficial to promote the degradation kinetics.The presence of chloride ion accelerates the removal of TMP benefitting from the generation of active chlorine while the concentration of sodium sulfate exhibits little effect on the mineralization efficiency.Finally,the possible degradation pathway of TMP on BDD electrode was proposed,which mainly includes the hydroxylation,demethoxylation,cleavage and open ring reactions,realizing the mineralization into CO_(2),NO_(3)^(-)and H_(2)O.
作者
赵丹荻
贾博
何亚鹏
黄惠
陈步明
郭忠诚
ZHAO Dandi;JIA Bo;HE Yapeng;HUANG Hui;CHEN Buming;GUO Zhongcheng(Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming,650093,China;Metallurgical Electrode Material Engineering Technology Research Center of Yunnan Province,Kunming,650106,China;Kunming Hendera Technology Co.LTD.,Kunming,650106,China)
出处
《环境化学》
CAS
CSCD
北大核心
2022年第10期3425-3434,共10页
Environmental Chemistry
基金
国家自然科学基金(22002054,52064028)
云南省基础研究计划(202101AU070157,202101AS070013)
中国博士后科学基金(2018M633418)资助。
关键词
掺硼金刚石电极
电催化氧化
抗生素污染物
降解动力学
降解路径.
boron doped diamond electrode
electrochemical oxidation
antibiotic pollutants
degradation kinetics
degradation pathway
