日光辐照草酸铁盐体系降解水中低浓度混合药物及产物的生物毒性评价  

Degradation of the Mixed Pharmaceuticals with Low Concentration in Aqueous by Solar /Ferrioxalate System and Process Evaluation Through Toxicity Bioassay

作　　者：熊振湖[1,2] 于万禄[1] 胡品[1] 

机构地区：[1]天津城市建设学院环境与市政工程系,天津300384 [2]水质科学与技术天津市重点实验室,天津300384

出　　处：《环境科学》2010年第10期2336-2343,共8页Environmental Science

基　　金：国家自然科学基金项目(50878138);天津市自然科学基金重点项目(07JCZDJC01700)

摘　　要：在太阳光辐照下以三草酸合铁酸钾为催化剂,分解H2O2产生·OH,对水中的甲硝唑、双氯芬酸钠、磺胺甲基异唑和布洛芬4种常见的痕量药物污染物间歇降解与矿化,并且对降解前后水溶液的毒性进行了评价.以体系的总有机碳为指标,探讨了H2O2的初始浓度、三草酸合铁酸钾的投加量、体系的pH值等因素对水溶液中TOC去除率的影响,确定了最佳操作条件,根据4种药物的化学结构解释了它们在水中的降解速度.以药物水溶液对小球藻的EC50值为指标,对4种药物的联合毒性,以及降解中间产物的生物毒性做出了评价.结果表明,当4种药物的初始浓度都为20mg·L-1时,降解过程适宜条件是pH值为3,H2O2的初始浓度为300mg·L-1,三草酸合铁酸钾的投加量为75mg·L-1.4种药物的降解速度为:甲硝唑>布洛芬>磺胺甲基异唑>双氯芬酸钠.随着中间产物的生成与降解,药物水溶液的生物毒性有先增大后迅速减小的趋势.最后给出了Solar/FeOx/H2O2体系降解水中低浓度药物的表达式.Under the sunlight irradiation,the four common trace pollutants such as metronidazole,diclofenac,sulfamethoxazole and ibuprofen were degradated and mineralized by the hydroxyl radical（·OH） generated from decomposition of H2 O2 catalyzed by ferrioxalate（FeOx）,and the toxicity of the water solution containing degradated products and intermediates were evaluated.The factors affecting the removal of the TOC,such as the initial concentration of H2 O2,FeOx,and the pH,were investigated through an indicator of total organic carbon.The disappearing rate of pollutants in aqueous solution was explained according to the chemical structure of the pharmaceuticals;the biotoxicity of the pharmaceuticals and the intermediates were evaluated by EC50 value of pharmaceutical solution to the Chlorella.The appropriate operating conditions were achieved at pH 3 with initial concentrations of 300 mg·L^-1 H2 O2 and 75 mg·L^-1 FeOx at the conditions such as the initial concentration of four drugs were 20 mg·L^-1,respectively.The order of the degradation rate for the pharmaceuticals is metronidazole ibuprofen sulfamethoxazole diclofenac.During the reaction,the biological toxicity increases with time and then decreases rapidly,along with appearance and disappearance of intermediates.Finally,a model on reaction mechanism was proposed,where Solar /FeOx /H2 O2 system was used for the degradation of the pharmaceuticals with low concentration in aqueous solution.

关 键 词：太阳光辐照 草酸铁钾 痕量药物污染物 降解与矿化 生物毒性 

分 类 号：X703.1[环境科学与工程—环境工程]