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。     

高镁铝合金在喷射成形过程中显微组织的变化

研究了高镁铝合金在喷射成形过程中显微组织的变化。沉积态高镁铝合金基体呈全部等轴晶组织并存在少量显微孔洞是沉积态组织的主要特征。分析了等轴晶组织和显微孔洞在喷射成形中生成的机制。     

双阳河水质初步评价

本文叙述了双阳河水质状况，根据双阳河水质现状进行了初步评价。并提出了有关治理污染的建议。