UV/Cu_(2)O/H_(2)O_(2)耦合强化降解左旋氧氟沙星  

Degradation of levofloxacin by UV/Cu2O/H_(2)O_(2)

作　　者：徐君君 张熙茹 杜义平 郑跃[2] 李岐 赵莹莹[1] Junjun XU;Xiru ZHANG;Yiping DU;Yue ZHENG;Qi LI;Yingying ZHAO(College of Chemistry and Chemical Engineering,Bohai University,Jinzhou,121000,China;School of Chemical and Environmental Engineering,Liaoning University of Technology,Jinzhou,121000,China)

机构地区：[1]渤海大学化学化工学院,锦州121000 [2]辽宁工业大学化学与环境工程学院,锦州121000

出　　处：《环境化学》2021年第5期1342-1351,共10页Environmental Chemistry

基　　金：国家自然科学基金(21607012);辽宁省自然基金指导计划(2019-ZD-0695);渤海大学博士启动金(0518bs018)资助.

摘　　要：选择快速高效的方法降解左氧氟沙星(LEV)对抗生素废水的处理具有重要的实际意义.采用UV/Cu_(2)O/H_(2)O_(2)组合体系降解LEV,探讨了Cu_(2)O投加量、H_(2)O_(2)浓度、初始pH值、自由基淬灭剂和无机阴离子等影响因素对LEV降解的影响及机制.结果表明,与单一UV、单一Cu_(2)O、UV/H_(2)O_(2)、Cu_(2)O/H_(2)O_(2)、UV/Cu_(2)O相比,UV/Cu_(2)O/H_(2)O_(2)体系显著提高了LEV的去除率,当Cu_(2)O投加量为0.1 g·L^(−1),H_(2)O_(2)浓度为2 mmol·L^(−1),pH=3.2,LEV浓度20 mg·L^(−1),反应5 h,LEV去除率达到92.3%.自由基淬灭实验表明,反应中主要的活性物种是·OH和h+.采用LC-MS方法检测到8种中间产物,UV/Cu_(2)O/H_(2)O_(2)体系通过逐步去除LEV官能团,将其降解为小分子物质.大肠杆菌毒性实验表明,LEV的最终产物无抗菌性.Cl^(−)、SO_(4)^(2−)和NO_(3)^(−)对UV/Cu_(2)O/H_(2)O_(2)体系降解LEV的抑制作用较小,而H_(2)PO_(4)^(-)的抑制作用较大.It is practically important to develop approaches that can rapidly and efficiently degrade Levofloxacin(LEV)in wastewater.The degradation of LEV in UV/Cu_(2)O/H_(2)O_(2) combined system was investigated in the present study,and the effects of reaction conditions,including the loading of Cu_(2)O,concentration of H_(2)O_(2),pH,radical scavengers and inorganic anions on the degradation of LEV,were studied.Results showed that compared with single UV,single Cu_(2)O,UV/H_(2)O_(2),Cu_(2)O/H_(2)O_(2),UV/Cu_(2)O systems,the UV/Cu_(2)O/H_(2)O_(2) system effectively degraded LEV in water.More than 92.3%of LEV(20 mg·L^(−1))was removed by the UV/Cu_(2)O/H_(2)O_(2) system within 5 h treatment,under the reaction conditions of Cu_(2)O 0.1 g·L^(−1),H_(2)O_(2)2 mmol·L^(−1) and pH=3.2.Quencher experiments indicated that hydroxyl radicals and holes were the primary reactive species for degradation of LEV.LC-MS analyses revealed that eight intermediates were generated during degradation,and LEV was broken down into small products via gradually removing various functional groups.Toxicity studies of E.coli showed that degradation products had no antibacterial properties.Cl^(−),SO_(4)^(2−) and NO_(3)^(−) exhibited little effect on the removal of LEV,whereas the presence of H_(2)PO_(4)^(-) markedly decreased the oxidation rate of LEV.

关 键 词：左氧氟沙星 Cu_(2)O 自由基淬灭剂 毒性 无机阴离子 

分 类 号：X703[环境科学与工程—环境工程]