城市径流雨水溶解性有机质特征及其与典型重金属的作用机制研究

发布时间：2018-11-12 11:24

【摘要】：地表径流污染已经逐渐成为城市面源污染的重要组成部分。随着城市化快速发展,自然下垫面逐渐被不透水材料所取代,汽车保有量的急剧增加和人类的生产生活活动,导致路面径流含有大量有机污染物、重金属等。其中溶解性有机质DOM(Dissolved organic matter)是有机污染物的主要组成部分。DOM中因为含有大量不饱和结构、官能团,其中包括羟基、羧基、羰基、胺基等,这些结构容易与径流中重金属结合发生络合反应,改变重金属的赋存形态,从而对其迁移转化及其生物有效性产生很大的影响。本文以北京市地表径流为研究对象,研究城市地表径流在冬、夏季不同功能区不同下垫面中溶解性有机质特征及其与典型重金属的作用机制,(1)发现在冬季径流中,DOC、TP、浊度普遍大于夏季,氨氮则相反,地表径流pH值在冬、夏季分别为中性、微碱性。(2)通过运用紫外可见光光谱技术、三维荧光光谱技术对地表径流中DOM进行定性表征。结果表明各功能区中,冬、夏季遵循绿地面积与径流雨水中腐殖酸含量成正比的规律;冬季地表径流DOM以陆源为主,夏季以陆源、微生物源混合为主;冬、夏季地表径流样品均含有4个组分,其中1种类蛋白,3种腐殖酸。最后本文通过荧光淬灭滴定实验,研究夏季径流雨水中DOM的不同组分与重金属Cu~(2+)、Pb~(2+)、Zn~(2+)之间的结合机制。研究结果显示(1)PARAFAC将获得的样品都分解成2类6个不同的组分,1种腐殖酸,1种类蛋白;类蛋白物质的荧光强度与Cu~(2+)、Pb~(2+)的淬灭率要强于腐殖酸,而Zn~(2+)只与类蛋白淬灭;(2)通过使用二维相关同步光谱发现DOM对重金属Cu~(2+)、Pb~(2+)、Zn~(2+)的敏感性呈现递减趋势,二维相关异步光谱发现Cu~(2+)、Pb~(2+)、Zn~(2+)会先与位于270-300nm附近类蛋白光谱带反应。
[Abstract]:Surface runoff pollution has gradually become an important part of urban non-point source pollution. With the rapid development of urbanization, the natural underlying surface is gradually replaced by impermeable materials, the rapid increase of vehicle ownership and human life activities, resulting in a large number of road runoff organic pollutants, heavy metals and so on. Dissolved organic matter (DOM (Dissolved organic matter) is the main component of organic pollutants. DOM contains a large number of unsaturated structures, functional groups, including hydroxyl, carboxyl, carbonyl, amine, etc. These structures are easy to react with heavy metals in runoff and change the forms of heavy metals, which has a great influence on their migration, transformation and bioavailability. In this paper, the characteristics of dissolved organic matter in different underlying surfaces of different functional areas in winter and summer and its mechanism of interaction with typical heavy metals in urban surface runoff in Beijing were studied. (1) in winter runoff, DOC, was found. The turbidity of TP, is generally higher than that of summer, while ammonia nitrogen is opposite. The pH value of surface runoff is neutral and slightly alkaline in winter and summer, respectively. (2) DOM in surface runoff is characterized qualitatively by using UV-Vis spectroscopy and three-dimensional fluorescence spectroscopy. The results showed that the greenbelt area was proportional to the humic acid content in runoff Rain Water in winter and summer, and the surface runoff DOM was mainly terrestrial source in winter, land source in summer and mixed microbial source in summer. The surface runoff samples in winter and summer all contained four components, one kind of protein and three kinds of humic acid. Finally, the binding mechanism between different components of DOM and heavy metals Cu~ (2), Pb~ (2) and Zn~ (2) in summer runoff was studied by fluorescence quenching titration. The results showed that (1) the samples were decomposed into 2 groups and 6 different components, one humic acid and one kind of protein by PARAFAC. The fluorescence intensity of protein-like substances and the quenching rate of Cu~ (2) and Pb~ (2) were stronger than those of humic acid, while Zn~ (2) only quenched with protein like. (2) the sensitivity of DOM to heavy metals Cu~ (2), Pb~ (2), Zn~ (2) was decreased by using two dimensional correlation synchronous spectroscopy. Cu~ (2), Pb~ (2) were found by two dimensional correlation asynchronous spectroscopy. Zn~ (2) first reacts with the spectral band of protein-like proteins located near 270-300nm.
【学位授予单位】：北京建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

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