Photodegradation of acetochlor in water and UV photoproducts identified by mass spectrometry

The sunlight photodegradation half-lives of 20 mg/L acetochlor were 151, 154 and 169 days in de-ionized water, river water and paddy water, respectively. When exposed to ultraviolet (UV) light, acetochlor in aqueous solution was rapidly degraded. The half-lives were7.1, 10.1, and 11.5 min in de-ionized water, river water and paddy water, respectively. Photopreduets of acetochlor were identified by gas chromatography/mass spectrometry(GC/MS) and found at least twelve photoproducts resulted from dechlorination with subsequent hydrtrxylation and cyclization processes. The chemical structures of ten photoproducts were presumed on the basis of mass spectrum interpretation and literature data. Photoproducts are identified as 2-ethyl-6-methylaniline; N, N-diethylaniline ; 4, 8-dimethyl-2-oxo- 1,2,3,4- tetrahydroquino-line; 2-oxo-N-(2-ethyl-6-methylphenyl)-N-(ethoxymethyl) acetamide; N-(ethoxymethyl)-2‘-ethyl-6‘-methylformanilide; 1-hydroxyaeetyl-2-ethoxyl-7-ethylind ole; 8-ethyl-l-ethoxymethyl-2-oxo-1, 2, 3, 4-tetrahydroquinoline; 4, 8-dimethyl-l-ethoxymethyl-2-oxo-1, 2, 3, 4-tetrahydroquinoline; 2-hydroxy-2‘-ethyl-6‘-methyl-N-(ethoxymethyl) acetanilide and a compound related to acetochlor. The other two photoproducts were detected by GC/MS although their chemical structure was unknown.     

浅谈长江船舶污染及治理对策

长江是我国第一大河流，是内河航运业的黄金水道，在随着长江水系不断开发利用，航运业突飞猛进的同时，长江船舶污染也正在加剧，中央电视台焦点访谈、经济半小时分别于98年6月给予曝光，长江船舶污染问题得以成为各级领导和世人关注的热点。本文对长江污染的现状、特点、原因进行浅析，提出了几条整治措施及建议，和大家共同探讨。近年来，随着经济建设和航运业的迅猛发展，长江水域的各种船舶急剧增加，船舶污油及生活垃圾严重污染长江，重大污染事故时有发生，使长江水质、生态环境、葛洲坝水利枢纽的正常运转均受到不同程度的影响，长…     

嘉定城区河流水质现状评价及污染防治对策

通过对嘉定中心城区河流的水质现状调查和评价，提出了引清排污、加强市政措施等污染防治对策。     

淮河江苏段石油类污染及防治

分析淮河江苏段水体中主要污染物－石油类的分布况及其变化趋势，并对其成因及防治进行了初步探讨。     

城市河流污染底质的疏浚工程费用函数及其应用

本文通过对航道疏浚工程有关定额的详细分析,提出了适合于估算城市河流污染底质疏浚工程费的费用函数式,并以黄浦江某支流流经上海市区的部分为例,对其底质严重污染河段的疏浚工程费用作了估算,该法快速简便。