Enhanced ozonation degradation of atrazine in the presence of nano-ZnO： Performance, kinetics and effects  

作　　者：Xiangjuan Yuan Xuan Yan Haiming Xu Dongya Li Lei Sun Gang Cao Dongsheng Xia 

机构地区：[1]School of Enuironmental Engineering, Wuhan Textile University, Wuhan 430073, China [2]Engineering Research Center for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan 430073, China

出　　处：《Journal of Environmental Sciences》2017年第11期3-13,共11页环境科学学报（英文版）

基　　金：supported by the state supported project funds for research;demonstration on the key technology for clean production in textile printing and dyeing (2014BAC13B02)

摘　　要：Enhanced ozonation degradation of atrazine（ATZ） with nano-ZnO（nZnO） as catalyst and the influences of the operational parameters have been investigated through semi-continuous experiments in this study. The results demonstrated that the combination of ozone（O3） and nZnO showed an obvious synergetic effect and the ATZ degradation conformed to pseudo-first-order kinetics. An improvement of ATZ degradation efficiency by 41.8% and pseudo-first-order rate constant by more than a factor of four was obtained in the O3/nZnO process after 5 min of reaction compared to O3 alone. Meanwhile, the degradation efficiency of ATZ was gradually enhanced with increasing nZnO dosage and initial pH in the range from 3.0 to 8.0, and a higher amount of ATZ was degraded when the initial concentration of ATZ rose from 0.5 to 5 mg/L. Additionally, sulfate ion, chloride ion, nitrate ion and low concentrations of humic acid substances led to enhancement of the ATZ degradation. The notable decrease of ATZ removal efficiency observed in the presence of radical scavengers and the results of free radical tests indicated thatUOH is the dominant active radical species. The mechanism investigation demonstrated that the enhancement effect could be attributed to the introduction of nZnO,which could promote the utilization of O3, enhance the formation of superoxide radical, and further accelerate the production of hydrogen peroxide and the generation of OH/O2-.Enhanced ozonation degradation of atrazine（ATZ） with nano-ZnO（nZnO） as catalyst and the influences of the operational parameters have been investigated through semi-continuous experiments in this study. The results demonstrated that the combination of ozone（O3） and nZnO showed an obvious synergetic effect and the ATZ degradation conformed to pseudo-first-order kinetics. An improvement of ATZ degradation efficiency by 41.8% and pseudo-first-order rate constant by more than a factor of four was obtained in the O3/nZnO process after 5 min of reaction compared to O3 alone. Meanwhile, the degradation efficiency of ATZ was gradually enhanced with increasing nZnO dosage and initial pH in the range from 3.0 to 8.0, and a higher amount of ATZ was degraded when the initial concentration of ATZ rose from 0.5 to 5 mg/L. Additionally, sulfate ion, chloride ion, nitrate ion and low concentrations of humic acid substances led to enhancement of the ATZ degradation. The notable decrease of ATZ removal efficiency observed in the presence of radical scavengers and the results of free radical tests indicated thatUOH is the dominant active radical species. The mechanism investigation demonstrated that the enhancement effect could be attributed to the introduction of nZnO,which could promote the utilization of O3, enhance the formation of superoxide radical, and further accelerate the production of hydrogen peroxide and the generation of OH/O2-.

关 键 词：NANO-ZNO ATRAZINE Catalytic ozonation Reaction mechanism 

分 类 号：X592[环境科学与工程—环境工程]