高锰酸钾氧化去除水中三氯生动力学研究

Kinetics on triclosan oxidation by potassium permanganate in drinking water

为了揭示高锰酸钾氧化去除水中三氯生的动力学规律,通过烧杯试验研究得出高锰酸钾氧化三氯生的反应速率常数,同时探讨高锰酸钾浓度、pH、温度等因素对反应速率常数的影响.试验结果表明:不同高锰酸钾浓度下,三氯生能够被迅速氧化,氧化三氯生的反应符合二级反应动力学,二级反应动力学常数K=0.331 6 mL.s-1.mol-1.pH对反应速率常数有显著影响,在pH为5、7时,K分别达到最小值和最大值.高锰酸钾氧化三氯生的反应速率随着反应温度的增加而增加,该反应表观活化能Ea为32.35 kJ.mol-1,说明该反应在一般水处理条件下较容易发生.高锰酸钾是一种快速、高效去除水中三氯生的氧化剂.

Jar tests were conducted to expose the kinetic law of triclosan oxidation by potassium permanganate in aquatic environment.The rate constant of the reaction was obtained,meanwhile,the factors influencing the value of K,such as potassium permanganate dosage,pH value and temperature,were investigated.The results showed that triclosan was rapidly oxidized by potassium permanganate in aqueous solution with different initial concentrations of potassium permanganate,and second-order reaction kinetics was observed between triclosan and potassium permanganate with second-order reaction rate constant K=0.331 6 mL·s-1·mol-1.The second-order reaction rate constant was influenced by pH values,and K reached its lowest and highest level at pH 5 and 7 respectively.The rate of oxidation increased with the temperature increasing,and the reaction activation energy E a=32.35 kJ·mol-1,which revealed that the oxidation reaction between triclosan and potassium permanganate was feasible under usual water treatment condition.Therefore,potassium permanganate is a feasible oxidant which can removal the triclosan quickly and efficiently.