成都市区河道淤泥的铅同位素组成特征及铅污染来源研究

【作者】 闫秋实；

【导师】 尹观； 葛良全；

【作者基本信息】 成都理工大学 ， 地球化学， 2004， 硕士

【摘要】 本课题是“四川省成都市经济区生态地球化学调查”中铅同位素示踪项目下的一个子项目。 作者对成都市市区主要水系(府河、南河、沙河)的表层沉积物(淤泥)进行了布点采样及样品的铅同位素比值测定工作。应用环境铅同位素示踪原理，通过对每条河流及一些特殊点的淤泥样品的铅同位素组成特征的分析，并结合一些环境因素，示踪和查明了成都市市区河道淤泥铅污染主要端元的分布规律和相对贡献。 通过资料收集、样品采集、化学分离提纯、质谱分析测定及数据处理等各环节的细致工作，获得了以下结论： 1) 成都市两种重要的铅污染源(车用燃油和燃煤灰尘)的铅同位素组成具有明显分带的特征，特别汽油铅的铅同位素组成显著区别于燃煤铅的同位素组成，可以用以示踪和鉴别成都市河道淤泥的铅污染来源。 2) 成都市河道淤泥的铅来源大致可分为四类：地质体、车用燃油尾气、燃煤灰尘及工业排放。燃煤灰尘和工业排放的贡献在高(铅)污染的沙河河段十分显著，低污染的河段(府河、南河)则更多的具有燃油尾气的铅同位素组成特征，远离市区的上游河段沉积物的铅同位素组成则代表本地地质体的背景值特征。 3) 以往相关研究中鲜有涉及的柴油铅源应当予以重视。本次研究中有两个样品点(CRD-11和CRD-15)带有明显的柴油铅贡献特征。 4) 本文利用铅同位素示踪技术，并引入了Richard Bindler(2001)用于分析湖相沉积物的两端元铅同位素混合模型，在成都市河道淤泥铅同位素示踪研究中取得了良好的效果：大多数获得的“过量铅”的同位素组成都与相应的端元物质基本符合。本研究表明，环境铅同位素示踪技术是进行河道淤泥铅污染源示踪的行之有效的方法。 5) 利用铅同位素示踪技术不但可以追踪城市河道淤泥的铅污染源，还可以为河道淤泥中其他元素的来源研究提供一些重要的线索。更多还原

【Abstract】 The author measured the ratios of lead isotopes of the samples that are from main rivers in Chengdu city, NanHe river, FuHe river and ShaHe river. By the principle of Environmental Lead Isotope Tracing, the lead isotope composition of surface layer’s sediment of every river and some special samples have been discussed, which helps to, with some factors of environment, trace and find out the distribution rules of the main contributors for lead pollution in riverway sediment and the proportion of contribution.Conclusions have been gained through many serious-minded researches such as collecting materials, sampling, chemic separate and purification, mass spectrum measuring, and data analyzing. The conclusions are as follow:1)The lead isotope composition of two major lead pollution sources ( leaded gasoline and coal) differed considerably from each other, which make it possible to trace the sources of the lead pollution of riverway sullage.2)The lead pollution sources of Chengdu’s riverway sullage include geological condition, leaded gasoline , the ash of coal and industrial refuses. The contribution of the coal ash and industial refuses is more in hard-polluted ShaHe river, and the less-polluted rivers, NanHe river and FuHe river, feature with leaded gasoline’s lead isotope composition. The lead isotope composition of upriver far from downtown, can be regard as the background of local geological condition.3)The source of diesel oil, which was rarely dealt with before, should be pay more attention to. Two samples (CRD-11 and CRD-15) seems be strongly influenced by this kind of source.4)Lead Isotope Tracing Technology and the lead isotope mixing model, which was used by Richard Bindler to study lake sediment, are introduced to this research and run effectively to tracing lead pollution of sediment of the rivers in Chengdu.5)Lead Isotope Tracing Technology can be used to not only trace the sources of the lead pollution of urban riverway sullage, but also help to offer some important clues for the sources of other elements in sediments.更多还原