采用氯离子(Cl-)作为阴离子活化剂,活化单过硫酸氢钾(PMS)氧化降解甲氧苄啶(TMP).研究了Cl-/PMS体系降解TMP中起主要作用的活性物种,同时考察了Cl-浓度、PMS投加量、初始pH值对降解效果的影响,并研根据中间产物推断了TMP降解路径.实验结果表明,Cl-/PMS体系中的主要活性物种是Cl-和PMS直接反应生成的活性氯.降解过程符合拟一级反应动力学模型(R2>0.99);随着Cl-浓度和PMS投加量增加,反应速率常数kobs增大;初始pH范围在5.0~9.0范围内,随着pH值的增大,TMP的去除率先减小后增大;TMP主要经历了氯取代和羟基取代过程,其核心结构上没有实质性的分解.%Cl- activated peroxymonosulfate (PMS)wasusedto degrade trimethoprim (TMP).The active subustance-generated in Cl /PMS systemwas identified. Effects of chloride concentration, PMS dosage, initial pH value on the degradation efficiency of TMP were evaluated. Degradation pathway of TMP was exploredbasedon the identification of degradation intermediates. The results indicated thatthedegradationof TMP was mainly ascribedto the active chlorine-species, which was generatedfrom the direct reaction of Clwith PMS .TMP degradation kinetics fitted well with the-pseudo-first-ordermodel. The reaction constant increased with the increasing of the Clconcentration and PMS dosage. The corresponding degradation rate decreased firstly and then increased when the initial pH varied between5.0 and 9.0. The results also indicated that TMP was notsubstantially destructed upon reactions with active chlorine specieswhileawide variety of (multi) chlorinated and hydroxylated productsare formed.
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