上海城市地表灰尘重金属粒级效应与赋存形态研究  

Particle size distribution of heavy metals in urban surface dusts in Shanghai

作　　者：王丽丽[1] 刘敏[1] 欧冬妮[1] 常静[2] 许世远[1] 

机构地区：[1]华东师范大学资源与环境科学学院教育部地理信息科学重点实验室,上海200062 [2]上海大学通信与信息工程学院遥感与空间信息科学研究中心,上海200072

出　　处：《华东师范大学学报（自然科学版）》2009年第6期64-70,127,共8页Journal of East China Normal University(Natural Science)

基　　金：国家自然科学基金重点项目(40730526)

摘　　要：以上海中心城区地表灰尘中Zn，Cr和Pb为研究对象，初步探讨粒级效应对其含量及赋存形态的影响．研究结果显示：（1）各功能区地表灰尘粒径分布具有较高一致性，小于75μm地表灰尘占总量的47．4％，高于其他3个粒径级别；（2）上海地表灰尘重金属处于较高污染水平，Zn，Cr和Pb最高值分别出现在商业区、工业区和居民区；（3）地表灰尘重金属累积具有明显的粒级效应，重金属主要富集在小于75μm粒径颗粒物中，Zn，Cr和Pb相对质量分数分别为32．8％，36．0％和30．0％，其次为75～150μm，相对质量分数分别为31．4％，28．7％和27．6％；（4）Zn，Cr和Pb五种赋存形态在各粒级中分布较一致，Zn以碳酸盐结合态和铁锰氧化物结合态为主，Cr以残渣态为主，Pb以铁锰氧化物结合态为主，生物活性Zn，Pb和Cr，粒径分布对Zn，Cr和Pb赋存形态影响较小．This study was undertaken to assess the impact of particle size distribution on the heavy metal concentrations and chemical fractions in urban surface dusts in Shanghai. The result showed that there was 47.4% of surface dusts under 75 μm, higher than other fractions. It showed obvious difference in the spatial distribution of heavy metals in urban surface dusts, Zn had the highest concentration in the commercial district, while Cr in the industrial district and Pb in the residential district. Heavy metals were mainly existed in the smaller particle size fractions and the 75 μm part contained the highest concentration. A five-step sequential extraction of urban surface dusts showed that Zn occurred predominantly in the carbonate bound fraction and reducible fraction, while Cr was the highest in the residual fraction and Pb in the reducible fraction. Considering the exchangeable and carbonate fractions, the comparative mobility of the metals in urban surface dusts probably decreased in the following order： Zn〉 Pb〉 Cr.

关 键 词：粒级效应 城市地表灰尘 重金属 赋存形态 

分 类 号：X502[环境科学与工程—环境工程]