乌鲁木齐采暖期TSP、PM10、PM5、PM2.5中重金属污染水平评价

采用石墨炉原子吸收分光光度法、双道原子荧光光谱法研究乌鲁木齐市采暖期前期与后期不同粒径大气颗粒物(TSP、PM_(10)、PM_5、PM_(2.5))中Hg、As、Zn、Pb、Ni等5种重金属元素的质量浓度,并对重金属污染水平进行评价。Hg质量浓度为0.3~5.7 ng/m3;As质量浓度为15.3~122.5 ng/m~3;Zn质量浓度为298.0~1 686.5 ng/m~3;Pb质量浓度为0.5~88.8 ng/m~3;Ni质量浓度为10.4~25.5 ng/m~3。Igeo计算得出采暖期后期的TSP、PM_(10)、PM_5、PM_(2.5)中各重金属Igeo值均高于采暖期前期,其中Hg元素为严重污染;富集因子分析得出Hg、Zn元素的EFi值大于10,说明这些元素是人为源贡献。通过研究乌鲁木齐市不同时期、不同粒径大气颗粒物中各种重金属污染状况,为乌鲁木齐大气污染治理提供科学支持。

Evaluation on Heavy Metal Pollution Levels in TSP,PM10,PM5,PM2.5 during Heating Period of Urumqi

In this study, the concentration levels of five heavy metals (Hg, As, Zn, Pb and Ni) in different particles (TSP,PM₁₀,PM₅,PM_2.5) were measured and evaluated by using graphite furnace atomic absorption spectrometry and double channels-atomic fluorescence spectrometry, in early and late heating period of Urumqi. The results showed that the concentration of Hg, As, Zn, Pb and Ni was 0.3-5.7 ng/m³, 15.3-122.5 ng/m³, 298.0-1686.5 ng/m³, 0.5-88.8 ng/m³ and 10.4-25.5 ng/m³, respectively. The results of pollution index(I_geo)showed that the Igeo values of heavy metals in TSP,PM₁₀,PM₅,PM_2.5 in late heating period were higher than early heating period. And the pollution of Hg was very serious. Enrichment factor analysis showed that the EF_i values of Hg,Zn were higher than 10, which stated that main sources of this elements were human activity. Through the study of different kinds of heavy metals pollution in different atmospheric particulate matter and in different period, scientific support for Urumqi air pollution control was proposed.