The mechanism and pathway of the ozonation of 4-chlorophenol in aqueous solution  

作　　者：PI Yunzheng WANG Jianlong 

机构地区：[1]Laboratory of Environmental Technology, Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084, China Laboratory of Environmental Technology, Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084, China

出　　处：《Science China Chemistry》2006年第4期379-384,共6页中国科学（化学英文版）

基　　金：This work was supported by the Excellent Young Teacher Program of Ministry of Education of China and the National Natural Science Foundation of China (Grant No. 50325824).

摘　　要：The removal efficiency of 4-chlorophenol by ozonation was studied, and the reaction mechanism and characteristic of ozonation of 4-chlorophenol were investigated. Ozone and hydroxyl radicals are two strong oxidants during the process of ozonation. The experimental results showed that when there was no scavenger to inhibit OH· radicals, an intermediate product, hydrogen peroxide was formed during the ozonation of 4-chlorophenol. Hydrogen peroxide reacted with ozone at neutral pH and produced hydroxyl radicals. Ozone at the dosage of 113 mg/L could remove 20 mg/L 4-chlorophenol and 39% TOC. With the complete inhibition of hydroxyl radicals, molecular ozone could effectively destroy 4-chlorophenol to form 4-quinone, which was subsequently oxidized to formic acid and oxalic acid. Two reaction pathways of the degradation of 4-chlorophenol by ozone and O3/OH· were proposed in this study. Ozonation is an effective method for reducing 4-chlorophenol, and has potential to practical application.The removal efficiency of 4-chlorophenol by ozonation was studied, and thereaction mechanism and characteristic of ozonation of 4-chlorophenol were investigated. Ozone andhydroxyl radicals are two strong oxidants during the process of ozonation. The experimental resultsshowed that when there was no scavenger to inhibit OH· radicals, an intermediate product, hydrogenperoxide was formed during the ozonation of 4-chlorophenol. Hydrogen peroxide reacted with ozone atneutral pH and produced hydroxyl radicals. Ozone at the dosage of 113 mg/L could remove 20 mg/L4-chlorophenol and 39% TOC. With the complete inhibition of hydroxyl radicals, molecular ozone couldeffectively destroy 4-chlorophenol to form 4-quinone, which was subsequently oxidized to formicacid and oxalic acid. Two reaction pathways of the degradation of 4-chlorophenol by ozone andO_3/OH· were proposed in this study. Ozonation is an effective method for reducing 4-chlorophenol,and has potential to practical application.

关 键 词：4-chlorophenol  ozone  hydrogen peroxide  4-quinone  HYDROXYL radicals. 

分 类 号：N[自然科学总论]