题 目：Investigation ofCataphotolysis of Organic Contaminants in Water
主讲人：Zhuangjie Li博士（Department of Chemistryand Biochemistry, California State University Fullerton, 终身副教授）
Irrigation of farmland consumedapproximately 80% of total water usage in California. Contamination ofCalifornia ground and surface water by pesticides, including herbicides andfungicides, due to agricultural application is an important environmental issuethat affects California welfare. Crops including vegetables and fruitcould be contaminated if the water containing pesticides is reused forirrigation. It therefore is important to remove pesticides from the irrigatedwater prior to its reuse. Traditional ways of cleaning water contaminatedwith organics are either costly or lead to formation of by-products. We aredeveloping methods to remove organics from water using sunlight cataphotolysisapproaches. Current investigation focus on coating nanomaterials on a glassplate for cataphotolysis of Propanil, Diuron, and Metolachor. It was found thatthese pesticides undergo cataphotolytic degradation, and the photolytic processfollows the first order chemical kinetics with a rate constant in the range of(0.8~2.5) x 10-3 min-1. Both ultraviolet and visiblecomponents of sunlight were found to contribute to the cataphotolysis. Study ofthe cataphotolysis products suggested that these organic contaminants werefinally oxidized into CO2 and NO2, which dissolved inwater giving rise to lower pH values than the neutral water. The experimentaldetail and the implication of the present work to future cleaning of theorganic contaminants from water are discussed.
Zhuangjie Li博士，1991年获美国韦恩州立大学物理化学博士学位，现任美国加州州立大学富尔顿分校（California State University Fullerton）化学和生物化学系终身副教授，美国化学学会会员。长期从事大气化学、水中挥发性有机污染物检测分析和大气污染物去除反应机制与动力学等方面的研究和教学工作，主持完成了包括美国国家自然科学基金项目、美国环境保护署科学研究基金项目在内的多项研究课题，是JPCA, CPL, JACS, JGR, IJCK, ES&T, PNAS等多个刊物的审稿人，也是美国国家科学基金（NSF）、美国国家研究开发和ACS-Petroleum等多个研究基金的评审人。