西安市城市灰尘环境污染及环境质量评价

【作者】 韩永明；

【导师】 杜佩轩； 李荣西；

【作者基本信息】 长安大学 ， 矿物学、岩石学、矿床学， 2003， 硕士

【摘要】 城市灰尘污染一方面是颗粒物污染，另一方面是重金属污染。城市灰尘颗粒物本身既是污染物，又是重金属污染的载体。 本论文从研究城市灰尘与总悬浮颗粒物的关系入手，研究二者的矿物组成，了解物质来源；研究二者的粒径分布，了解颗粒物的搬运沉积方式；研究二者的重金属含量特征，了解其相关性。从而建立起城市灰尘迁移循环基本模式，并且进行城市灰尘成因分类，这些转而进一步说明了城市灰尘与总悬浮颗粒物的相关性和相似性。 研究城市灰尘重金属污染从城市灰尘环境地球化学特征出发，研究西安市城市灰尘重金属元素背景值，查明其在西安市的分布情况，进行环境地球化学异常划分及异常解释，最终查明西安市城市灰尘重金属总体污染情况。结合国家土壤重金属环境质量标准，提出了城市灰尘重金属元素铅、锌、铬、铜、砷、汞、镉、银等的环境质量标准。 在上述城市灰尘重金属元素环境质量标准的基础上，采用指数分级评价法，进行西安市灰尘重金属污染环境质量综合评价。综合评价结果表明西安市城区城市灰尘都受到了重金属的污染，西安市绝大部分地区城市灰尘重金属污染以轻度污染为主，中度污染次之，极小部分地区重度污染，未见无污染和严重污染的地区。产生西安市城市灰尘重金属环境生态危害的最主要重金属污染元素为Cd，其次为Cu、Pb、Zn、Cr、Ag。As的污染很小，它只对部分地区产生轻度污染。更多还原

【Abstract】 The pollution of citydust can be shown in two aspect: pollution of grain and pollution of heavy metal. The grains of citydust are not only pollutants, but also the medium of pollution of heavy metal.This paper begins by studying the connection of citydust and suspending grain, studying their mineral composition to know about source of substance; studying their distribution of diameter of grain to know about the pattern of grain’s carry and deposition; studying their character of element of heavy metal to know about their correlation. Basing on the factors mentioned above, we put forward the basic mode of carry and cycle of citydust and do its classification. This in turn accounts for the correlation and similarity of citydust and suspending grain.To study pollution of heavy metal in xi’an city, we start by researching the character of environmental geochemistry of citydust. We research environmental background value of heavy metal of citydust, know its distribution in xi’an city, divide abnormality of environmental geochemistry, find out its overall pollution of heavy metal finally. Based on national standard of environmental value of the soil, we constitute standard of environmental value about element of heavy metal of citydust.Based on standard of environmental value about element of heavy metal in citydust mentioned above, we utilize the method of index and assess environmental value about element of heavy metal in xi’an city. The result shows: the citydust in xi’an city has all been polluted by heavy metal, in most areas the pollution being light; the mediate pollution being little; in very small areas the pollution being heavy. The most important pollute element of heavy metal in xi’an city causing environmental damage of citydust is cadmium; The less important pollute elements are copper, lead, zinc, chrome and silver. The pollution caused by arsenic is very small, which just makes small areas polluted in xi’an city.更多还原