饮用水中绿麦隆的氯胺化降解探究
|
摘要
系统研究了广泛应用的脲类除草剂绿麦隆在饮用水氯胺化消毒过程中的降解特性,考察了不同的氯胺投加量、pH值、溴离子浓度、水源等条件下绿麦隆的氯胺化降解规律。结果表明,绿麦隆的氯胺化降解速率较慢,由于氯胺自降解反应的存在,其反应机理也较为复杂。随着氯胺初始投加量逐渐增大,绿麦隆降解速率明显加快;不同pH值下绿麦隆的氯胺化降解速率变化明显,当pH值为6~7.5时降解速率较快,尤其在pH值为6时降解最快,在pH值为4.5时降解最慢;不同的溴离子背景浓度下,绿麦隆的氯胺化降解速率没有明显差异;在不同水质背景条件下,当pH值为6时,绿麦隆的氯胺化降解速率具有明显的差异性,而当pH值为7时绿麦隆的氯胺化降解速率变化不显著。
The degradation of chlortoluron as herbicide and precursor of NDMA under different experimental conditions during chloramination of drinking water was investigated.The degradation rate of chlortoluron during chloramination was relatively low and the reaction mechanism became more complex due to the chloramine self-decomposition.The higher initial dosage of chloramine was applied,the faster degradation rate of chlortoluron was found.The degradation of chlortoluron during chloramination was highly dependent on solution pH values.The peak degradation rates were found when pH values ranged from 6 to 7.5,especially at pH of 6.The lowest degradation rate was found at pH of 4.5.No significant difference in degradation rate of chlortoluron during chloramination was found with the addition of bromide ion.The degradation rate of chlortoluron during chloramination was highly impacted by background of water conditions at pH of 6.However,no significant difference was found at pH of 7 indeed.
The degradation of chlortoluron as herbicide and precursor of NDMA under different experimental conditions during chloramination of drinking water was investigated.The degradation rate of chlortoluron during chloramination was relatively low and the reaction mechanism became more complex due to the chloramine self-decomposition.The higher initial dosage of chloramine was applied,the faster degradation rate of chlortoluron was found.The degradation of chlortoluron during chloramination was highly dependent on solution pH values.The peak degradation rates were found when pH values ranged from 6 to 7.5,especially at pH of 6.The lowest degradation rate was found at pH of 4.5.No significant difference in degradation rate of chlortoluron during chloramination was found with the addition of bromide ion.The degradation rate of chlortoluron during chloramination was highly impacted by background of water conditions at pH of 6.However,no significant difference was found at pH of 7 indeed.
引文
[1]Acero J L,Real F J,Benitez F J,et al.Kinetics of reactions between chlorine or bromine and the herbicides diuron and isoproturon[J].J Chem Technol Biotechnol,2007,82(2):214-222.
[2]Xu B,Tian F X,Hu C Y,et al.Chlorination of chlortoluron:Kinetics,pathways and chloroform formation[J].Chemosphere,2011,83(7):909-916.
[3]Xu B,Qin C,Hu C Y,et al.Degradation kinetics and NNitrosodimethylamine formation during monochloramination of chlortoluron[J].Sci Total Environ,2012,417/418:241-247.
[4]Grasner S W,Weinberg H S,Richardson S D,et al.Occurrence of a new generation of disinfection byproducts[J].Environ Sci Technol,2006,40(23):7175-7185.
[5]焦中志,陈忠林,陈杰,等.氯胺消毒对消毒副产物的控制研究[J].哈尔滨工业大学学报,2005,37(11):1486-1488.
[6]许葆玖.给水处理理论[M].北京:中国建筑工业出版社,2000.
[7]汪雪姣.氯胺消毒特性及其副产物的生成研究[D].上海:同济大学,2008.
[8]高乃云,汪雪姣,周超,等.氯胺消毒对不同有机物生成消毒副产物的影响[J].同济大学学报:自然科学版,2009,37(12):1633-1637.
[2]Xu B,Tian F X,Hu C Y,et al.Chlorination of chlortoluron:Kinetics,pathways and chloroform formation[J].Chemosphere,2011,83(7):909-916.
[3]Xu B,Qin C,Hu C Y,et al.Degradation kinetics and NNitrosodimethylamine formation during monochloramination of chlortoluron[J].Sci Total Environ,2012,417/418:241-247.
[4]Grasner S W,Weinberg H S,Richardson S D,et al.Occurrence of a new generation of disinfection byproducts[J].Environ Sci Technol,2006,40(23):7175-7185.
[5]焦中志,陈忠林,陈杰,等.氯胺消毒对消毒副产物的控制研究[J].哈尔滨工业大学学报,2005,37(11):1486-1488.
[6]许葆玖.给水处理理论[M].北京:中国建筑工业出版社,2000.
[7]汪雪姣.氯胺消毒特性及其副产物的生成研究[D].上海:同济大学,2008.
[8]高乃云,汪雪姣,周超,等.氯胺消毒对不同有机物生成消毒副产物的影响[J].同济大学学报:自然科学版,2009,37(12):1633-1637.