溶液pH对高锰酸钾降解四环素动力学、产物和生物毒性的影响  

Effect of solution pH on kinetics,product and biotoxicity of tetracycline degradation by potassium permanganate

作　　者：詹洪生 李伟[1,2] 董丛健 刘玉灿 ZHAN Hongsheng;LI Wei;DONG Congjian;LIU Yucan(Key Laboratory of Northwest Water Resources,Environment and Ecology,MOE,Xi’an University of Architecture and Technology,Xi’an,710055,China;Key Laboratory of Environmental Engineering of Shaanxi Province,Xi’an University of Architecture and Technology,Xi’an,710055,China;School of Civil Engineering,Yantai University,Yantai,264005,China)

机构地区：[1]西安建筑科技大学,西北水资源环境与生态重点实验室,西安710055 [2]西安建筑科技大学,陕西省环境工程重点实验,西安710055 [3]烟台大学土木工程学院,烟台264005

出　　处：《环境化学》2024年第9期2956-2964,共9页Environmental Chemistry

基　　金：国家自然科学基金(51308437);陕西省自然科学基础研究基金(2021JM-365);陕西省教育厅重点实验室(20JS083)资助.

摘　　要：四环素(TC)是一种典型的酸碱两性化合物,其在水中的赋存形态受溶液pH影响.为探究TC降解路径和溶液毒性是否会随pH产生规律性变化,本研究考察了KMnO4氧化过程中,溶液pH(2、6、9和11)对TC降解动力学、降解产物和溶液毒性的影响规律及机制.结果表明,TC在KMnO4体系中的反应符合二级反应动力学模型,速率常数(kapp)为7.92 mol·L^(-1)·s^(-1)(pH=6)—37.74 mol·L^(-1)·s^(-1)(pH=11);使用超高效液相色谱-串联质谱法(UPLC-MS/MS)对经KMnO4处理后TC的降解产物进行定性分析,共有6种降解产物被检出,溶液pH为2、6、9和11时,分别有3、3、3和5种降解产物,表现出显著的pH依赖性.采用费氏弧菌、活性污泥细菌和斜生栅藻对氧化处理后的TC溶液进行毒性评价,发现部分降解产物具有比母体更强的生物毒性,ECOSAR模拟毒性数值也能佐证.Tetracycline(TC)is an acid-base amphoteric compound that undergoes changes in its species within aqueous solutions due to solution pH.This study aimed to investigate the relationship between solution pH and the degradation pathways,solution toxicity,and degradation kinetics of TC during KMnO4 oxidation,as well as the underlying mechanism.The results indicated that the reaction of TC in the KMnO4 system followed a second-order rate law.The pH-dependent rate constants(kapp)ranged from 7.92 mol·L^(-1)·s^(-1)(at pH 6)to 37.74 mol·L^(-1)·s^(-1)(at pH 11).Using the ultra-performance liquid chromatography-mass spectrometry(UPLC-MS/MS)method,qualitative analysis revealed a total of six degradation products.The number of degradation products identified varied with pH,with three,three,three,and five degradation products observed at pH 2,6,9,and 11,respectively.The degradation products exhibited significant pH dependence.The toxicity of the oxidized TC solution was assessed using Vibrio fischeri,activated sludge bacteria,and Scenedesmus obliquus.The study discovered that some of the degradation products exhibited higher toxicity than TC itself,which was further supported by simulated toxicity values obtained from ECOSAR.

关 键 词：四环素 超高效液相色谱-串联质谱法(UPLC-MS/MS) 化学氧化 降解产物 生物毒性 

分 类 号：X-1[环境科学与工程] O6[理学—化学]