Photochemical degradation of typical halogenated herbicide 2,4-D in drinking water with UV/H_(2)O_(2)/micro-aeration  

作　　者：CHU WenHai GAO NaiYun LI Chong CUI Jing 

机构地区：[1]State Key Laboratory of Pollution Control and Resources Reuse,Tongji University,Shanghai 200092,China [2]Department of Civil and Structure Engineering,Hong Kong Polytechnic University,Hong Kong,China

出　　处：《Science China Chemistry》2009年第12期2351-2357,共7页中国科学（化学英文版）

基　　金：Supported by the National Major Science and Technology Project(Grant No.2008ZX07421-002);"11th Five-year Plan"Science and Technology Support Projects(Grant No.2006BAJ08B06);973 program(Grant No.2006CB403204)

摘　　要：UV/H2O2/micro-aeration is a newly developed process based on UV/H2O2. Halogenated pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) photochemical degradation in aqueous solution was studied under various solution conditions. The UV intensity,initial 2,4-D concentrations and solution temperature varied from 183.6 to 1048.7 μW·cm-2,from 59.2 to 300.0 μg·L-1 and from 15 to 30℃,respectively. The concentration of hydrogen peroxide (H2O2) and pH ranged from 0 to 50 mg·L-1 and 5 to 9,and different water quality solutions (tap water,distilled water and deionized water) were examined in this study. With initial concentration of about 100 μg·L-1,more than 95.6% of 2,4-D can be removed in 90 min at intensity of UV radiation of 843.9 μW·cm-2,H2O2 dosage of 20 mg·L-1,pH 7 and room temperature. The removal efficiency of 2,4-D by UV/H2O2/micro-aeration process is better than UV/H2O2 process. The photodecomposition of 2,4-D in aqueous solution follows pseudo-first-order kinetics. 2,4-D is greatly affected by UV irradation intensity,H2O2 dosage,initial 2,4-D concentration and water quality solutions,but it appears to be slightly influenced by pH and temperature. There is a linear relationship between rate constant k and UV intensity and initial H2O2 concentration,which indicates that higher removal capacity can be achieved by the improvement of these factors. Finally,a preliminary cost analysis reveals that UV/H2O2/micro-aeration process is more cost-effective than the UV/H2O2 process in the removal of 2,4-D from drinking water.UV/H2O2/micro-aeration is a newly developed process based on UV/H2O2. Halogenated pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) photochemical degradation in aqueous solution was studied under various solution conditions. The UV intensity,initial 2,4-D concentrations and solution temperature varied from 183.6 to 1048.7 μW·cm-2,from 59.2 to 300.0 μg·L-1 and from 15 to 30℃,respectively. The concentration of hydrogen peroxide (H2O2) and pH ranged from 0 to 50 mg·L-1 and 5 to 9,and different water quality solutions (tap water,distilled water and deionized water) were examined in this study. With initial concentration of about 100 μg·L-1,more than 95.6% of 2,4-D can be removed in 90 min at intensity of UV radiation of 843.9 μW·cm-2,H2O2 dosage of 20 mg·L-1,pH 7 and room temperature. The removal efficiency of 2,4-D by UV/H2O2/micro-aeration process is better than UV/H2O2 process. The photodecomposition of 2,4-D in aqueous solution follows pseudo-first-order kinetics. 2,4-D is greatly affected by UV irradation intensity,H2O2 dosage,initial 2,4-D concentration and water quality solutions,but it appears to be slightly influenced by pH and temperature. There is a linear relationship between rate constant k and UV intensity and initial H2O2 concentration,which indicates that higher removal capacity can be achieved by the improvement of these factors. Finally,a preliminary cost analysis reveals that UV/H2O2/micro-aeration process is more cost-effective than the UV/H2O2 process in the removal of 2,4-D from drinking water.

关 键 词：2 4-dichlorophenoxyacetic acid endocrine disrupting chemicals PHOTOCHEMISTRY advanced oxidation processes pollution control cost analysis 

分 类 号：X703[环境科学与工程—环境工程]