Mechanism and kinetics of 2-chlorophenol decomposition using coupled ultrasound and electrocatalysis  

作　　者：WANG JiaDe ZHU RunYe CHEN Xia CHEN JianMeng 

机构地区：[1]Environmental Engineering Research Center,Zhejiang University of Technology,Hangzhou 310032,China

出　　处：《Science China Chemistry》2008年第6期577-585,共9页中国科学（化学英文版）

基　　金：Science and Technology Department of Zhejiang Province(Grant No.2005C23056)

摘　　要：A coupled ultrasound/electrocatalysis(US/EC) process was used to enhance the decomposition effi-ciency of organics.The synergetic kinetics and the mechanism of 2-chlorophenol(2-CP) decomposi-tion with coupled US/EC were studied.It was found that in a US/EC process 2-CP is attacked by active radicals(such as hydroxyl radicals) to form 2-chloro-p-benzoquinone,and the latter is oxidized to simple organic acids when the ring is opened.The enhancement factor expressed by the apparent rate constant of 2-CP decomposition with coupled US/EC is 1.324 at a current density of 20 mA·cm-2,an ultrasonic frequency of 20 kHz,an ultrasonic intensity of 0.27 W·cm-2,and a 2-CP initial concentration of 200 mg·L-1,which means that a synergetic effect exists.A model derived from Langmuir adsorption theory of solid surface and reaction kinetics equations can describe exactly the decomposition of 2-CP with coupled US/EC.The numerical values are in good agreement with the experimental data.The model parameters are associated with reaction conditions.A coupled ultrasound/electrocatalysis (US/EC) process was used to enhance the decomposition efficiency of organics. The synergetic kinetics and the mechanism of 2-chlorophenol (2-CP) decomposition with coupled US/EC were studied. It was found that in a US/EC process 2-CP is attacked by active radicals (such as hydroxyl radicals) to form 2-chloro-p-benzoquinone, and the latter is oxidized to simple organic acids when the ring is opened. The enhancement factor expressed by the apparent rate constant of 2-CP decomposition with coupled US/EC is 1.324 at a current density of 20 mA · cm?2, an ultrasonic frequency of 20 kHz, an ultrasonic intensity of 0.27 W · cm?2, and a 2-CP initial concentration of 200 mg · L?1, which means that a synergetic effect exists. A model derived from Langmuir adsorption theory of solid surface and reaction kinetics equations can describe exactly the decomposition of 2-CP with coupled US/EC. The numerical values are in good agreement with the experimental data. The model parameters are associated with reaction conditions.

关 键 词：ultrasound/electrocatalysis synergetic oxidation MECHANISM KINETICS 2-CHLOROPHENOL 

分 类 号：O643.1[理学—物理化学]