合肥市PM2.5和PM10中元素组成特征及重污染成因分析

通过对合肥市2018年大气PM_(2.5)和PM_(10)样品的采集,结合对样品中无机元素的测试分析,研究了PM_(2.5)和PM_(10)中的元素组成特征,并根据合肥市重污染天气和非污染天气下大气颗粒物中元素组成的差异性分析,探讨了合肥市重污染天气的主要污染物来源与成因.结果表明,本研究所检测的16种元素中,Si、Al、Mg和Ca这4种地壳元素在重污染天气的质量浓度较非污染天气低,可能是重污染状况下的静风天气引起的地面扬尘减少所造成的; S、Na、K、Cl、Ti、Fe、P、Cu和Ni等元素在重污染天气的质量浓度较非污染天气高,其中S元素的增幅最大,在重污染天气所占的比重和富集因子也大大提升,表明燃煤排放源是合肥地区重污染天气的主要污染成因;重金属元素含量低、富集因子大,其主要来源可能为垃圾焚烧、机动车和工业排放.

Elemental Composition Characteristics of PM2.5 and PM10, and Heavy Pollution Analysis in Hefei

Through the collection of atmospheric PM_2.5 and PM₁₀ samples in Hefei in 2018, combined with high-precision testing of elements in these samples, the elemental composition of PM_2.5 and PM₁₀ was studied during heavy pollution episodes and under non-pollution conditions. The main pollutant sources and causes of heavy pollution in Hefei are also discussed based on an analysis of the differences in the element composition of atmospheric particles. The results showed that, among the 16 elements detected, the mass concentrations of Si, Al, Mg, and Ca during heavy pollution episodes were lower than during non-polluted conditions. This may have been caused by a reduction in ground dust emission caused by calmer winds during heavily polluted conditions. In comparison, the mass concentrations of S, Na, K, Cl, Ti, Fe, P, Cu, and Ni were higher during heavy pollution episodes than during non-pollution conditions, and the difference was greatest for S. The proportion and enrichment factors for S were also greatly increased during heavy pollution events, indicating that its emission from coal burning is the main source of pollution in Hefei. The heavy metal content was low, however, and the enrichment factor was high, the main sources of which may be garbage incineration, motor vehicles, and industrial emissions.