摘要
磺胺类药物(sulfonamides,SAs)是十分常见且应用广泛的一类抗生素,由其引起的生态环境风险备受关注.本文研究了典型磺胺类药物磺胺醋酰(sulfacetamide,SFA)及磺胺噻唑(sulfathiazole,STZ)与二氧化氯(ClO_2)的反应机制及影响因素.结果表明,SFA及STZ与ClO_2的反应符合二级动力学模型,在pH 5.0和25℃条件下,反应二级速率常数分别为505.35 L·(mol·s)-1及1382.85 L·(mol·s)^(-1).温度、pH及水质条件等因素均对反应过程存在影响.SFA及STZ与ClO_2的反应机制受ClO_2投加量影响,在ClO_2过量时([ClO_2]∶[SAs]≥5),SAs得到一定程度的矿化,SFA及STZ与ClO_2的反应产物主要为乳酸、草酸及富马酸等有机酸;在ClO_2浓度较低时([ClO_2]∶[SAs]≤3),SAs与ClO_2发生亲电取代反应,生成毒性较强的氯代产物.
Sulfonamides( SAs) is a common and widely used class of antibiotics,which have received increasing attention due to their ecological and environmental risks. This study investigated the degradation mechanisms and influencing factors of the reaction of two sulfonamides( sulfonamide sfa,sulfathiazole STZ) with chlorine dioxide( ClO2).The results showed that the reaction of SFA and STZ with chlorine dioxide conformed to the second-order kinetics model,and the reaction rate constants were 505.35 L·( mol·s)-1and 1382.85 L·( mol·s)-1,respectively,under the condition of pH 5.0 and 25 ℃. Temperature,p H,humic acid and water quality influenced the reaction rates.The transformation mechanisms of SFA and STZ were dependent on the dosage of ClO2.With excess of ClO2( [ClO2]∶[SAs]≥5),SAs had a certain degree of mineralization,and the transformation products of SFA and STZ were mainly organic acids such as lactic acid,oxalic acid and fumaric acid. While at lower concentrations of ClO2( [ClO2]∶[SAs] ≤ 3),electrophilic substitution reaction occurred,which resulted in the generation of toxic chlorinated products in the solution.
作者
杨帅
余晓敏
郭学博
袁守军
王伟
胡真虎
YANG Shuai;YU Xiaomin;GUO Xuebo;YUAN Shoujun;WANG Wei;HU Zhenhu(School of Civil Engineering,Hefei University of Technology,Hefei,230009,China)
出处
《环境化学》
CAS
CSCD
北大核心
2019年第1期34-41,共8页
Environmental Chemistry
基金
国家自然科学基金(51578205)资助~~
关键词
磺胺醋酰
磺胺噻唑
二氧化氯
动力学
转化产物
抗生素
sulfacetamide
sulfathiazole
chlorine dioxide
kinetics
transformation products
antibiotics
