乌鲁木齐-昌吉地区重金属元素大气干沉降通量及来源研究

A Study of Heavy Metal Elements Fluxes and Sources from Dry Atmospheric Deposition in the Area of Urumqi and Changji

研究区是新疆的政治、经济和文化中心，开展重金属元素大气干沉降通量及来源研究，对研究土壤重金属来源及人类活动对土壤环境造成的影响具重大意义。从2008年5月到2009年5月，采用被动方式同时采集乌鲁木齐-昌吉地区大气干沉降样品共计11件。分析干沉降样品中Cd，Hg，Pb，As，Zn，Cu，Cr，Ni元素的含量，分别计算出各元素的年沉降通量。其中，重金属元素Zn，Pb，Hg，Cd，As的年沉降通量平均值分别为74.60 kg/km2· a-1、5.66 kg/km2· a-1、0.014 kg/km2· a-1、0.100 kg/km2· a-1、2.40 kg/km2· a-1。对比后发现，研究区大气降尘中重金属元素的年沉降通量及元素含量分布特征与采样点的工业产业布局模式具较好对应关系，其中，昌吉、八钢和乌鲁木齐大气污染程度较突出。研究区元素的大气沉降通量与同点位的土壤元素相关分析表明，Cu和Cd在两种介质中相关性显著，说明土壤中Cu和Cd积累与大气干沉降具密切关系，其他元素来源更为复杂。通过初步分析，得出研究区大气降尘中重金属元素来源主要为燃煤企业、冶炼厂、汽车尾气和建筑厂地排放的烟尘。

The study area is the political,economic and cultural center of Xinjiang province,the study of heavy metal el-ements fluxes and sources from dry atmospheric deposition will have a great significance for the study of origin of heavy metals in soils and the influence of human activities on soil environment.From May 2008 to May 2009,11 samples of dry atmospheric deposition were collected in the in the area of Urumqi and Changji,the samples were filtered and divid-ed into insoluble fractions and analyzed for Cd、Hg、Pb、As、Zn、Cu、Cr and Ni contents,the annual deposition fluxes of the 8 elements were Calculated respectively.Of these elements,the average deposition fluxes of the heavy metal elements Zn,Pb,Hg,Cd,As are 74.60、5.66、0.014、0.100 and 2.40 （kg/km2· a-1） respectively.Comparison of the deposition fluxes and the content distribution characteristics of the heavy metal elements shows that has a good correlation between the sam-pling points of Industrial Layout mode,the degree of air pollution in Changji、Eight-steel and Urumqi,is relatively more prominent,but far less than the area of Chengdu and Beijing.Correlation analysis of the deposition flux of elements in the atmosphere and that in soils at the same site in the study area shows significant correlation coefficient for both Cu and Cd,which indicates that the soil Cu and Cd contamination are attributed to dry atmospheric deposition,whereas for other elements more complicated sources need to be considered.Through a preliminary analysis,the main sources of heavy metal elements in atmospheric dust is the dust discharged from coal-fired enterprises、smelters、vehicle exhaust and construction Factory.