H_2O_2对4氯-酚辐射降解动力学的影响

Effect of H_2O_2 on the kinetics of radiolytical degradation 4-chlorophenol in aqueous solution

研究了4-氯酚在60Coγ辐照以及γ辐照-H2O2联合作用下的降解反应动力学。通过分析4-氯酚辐照分解过程中总有机碳(TOC)、Cl-浓度的变化,探讨了H2O2对4-氯酚辐照分解反应动力学的影响。实验结果表明:γ辐照-H2O2联合技术显著提高了4-氯酚的脱氯率及TOC去除率,表明协同效应存在。单独辐照及其与H2O2协同作用下4-氯酚的降解均符合一级反应动力学,当H2O2质量浓度分别为175、35、0 mg.L-1时,反应速率常数依次为:0.447 3、0.398 1、0.180 9 h-1。4-氯酚在辐照降解过程中释放Cl-的反应较复杂,不属于简单级数的动力学反应。

This work investigates the effect of hydrogen peroxide （H2O2） on the γ-ray irradiation induced degradation of 4-CP. The effect of hydrogen peroxide on the kinetics of the 4-CP radiolytical degradation was determined by analyzing the variation of the TOC and the chloride ion concentration during radiolysis of 4-CP in aqueous solution. The experimental results show that the hydrogen peroxide strongly promoted the TOC removal efficiency and the dechlorination rate of the 4-CP radiolysis. The radiolytical degradation of 4-CP by γ-ray irradiation alone or by γ-ray irradiation combined with hydrogen peroxide can be described by first-order reaction kinetics with rate constants of 0. 447 3 h^-1, 0. 398 1 h^-1, and 0. 180 9 h^-1 for hydrogen peroxide concentrations of 175, 35, and 0 mg. L^-1. The dechlorination of 4-chloropheonl is a rather complicated process, which can not be described by simple-order reaction kinetics.