Degradation mechanism of alachlor during direct ozonation and O-3/H2O2 advanced oxidation process

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境水质学国家重点实验室

	Degradation mechanism of alachlor during direct ozonation and O-3/H2O2 advanced oxidation process
	Qiang, Zhimin; Liu, Chao; Dong, Bingzhi; Zhang, Yalei
刊名	CHEMOSPHERE
	2010-01
卷号	78 期号:5 页码:517-526
关键词	Alachlor Ozone O-3/H2O2 Byproduct Mechanism Toxicity
中文摘要	The degradation of alachlor by direct ozonation and advanced oxidation process O-3/H2O2 was investigated in this study with focus on identification of degradation byproducts. The second-order reaction rate constant between ozone and alachlor was determined to be 2.5 +/- 0.1 M-1 s(-1) at pH 7.0 and 20 degrees C. Twelve and eight high-molecular-weight byproducts (with the benzene ring intact) from alachlor degradation were identified during direct ozonation and O-3/H2O2, respectively. The common degradation byproducts included N-(2,6-diethylphenyl)-methyleneamine, 8-ethyl-3,4-dihydro-quinoline, 8-ethyl-quinoline, 1-chloroacetyl-2-hydro-3-ketone-7-acetyl-indole, 2-chloro-2',6'-diacetyl-N-(methoxymethyl)acetanilide, 2-chloro-2'-acetyl-6'-ethyl-N-(methoxymethyl)-acetanilide, and two hydroxylated alachlor isomers. In direct ozonation, four more byproducts were also identified including 1-chloroacetyl-2,3-dihydro-7-ethyl-indole, 2-chloro-2',6'-ethyl-acetanilide, 2-chloro-2',6'-acetyl-acetanilide and 2-chloro-2'-ethyl-6'-acetyl-N-(methoxymethyl)-acetanilide. Degradation of alachlor by O-3 and O-3/H2O2 also led to the formation of low-molecular-weight byproducts including formic, acetic, propionic, monochloroacetic and oxalic acids as well as chloride ion (only detected in O-3/H2O2). Nitrite and nitrate formation was negligible. Alachlor degradation occurred via oxidation of the arylethyl group, N-dealkylation, cyclization and cleavage of benzene ring. After O-3 or O-3/H2O2 treatment. the toxicity of alachlor solution examined by the Daphnia magna bioassay was slightly reduced. (C) 2009 Elsevier Ltd. All rights reserved.
WOS记录号	WOS:000274370900004
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/21220]
专题	生态环境研究中心_环境水质学国家重点实验室
推荐引用方式 GB/T 7714	Qiang, Zhimin,Liu, Chao,Dong, Bingzhi,et al. Degradation mechanism of alachlor during direct ozonation and O-3/H2O2 advanced oxidation process[J]. CHEMOSPHERE,2010,78(5):517-526.
APA	Qiang, Zhimin,Liu, Chao,Dong, Bingzhi,&Zhang, Yalei.(2010).Degradation mechanism of alachlor during direct ozonation and O-3/H2O2 advanced oxidation process.CHEMOSPHERE,78(5),517-526.
MLA	Qiang, Zhimin,et al."Degradation mechanism of alachlor during direct ozonation and O-3/H2O2 advanced oxidation process".CHEMOSPHERE 78.5(2010):517-526.