2017—2018年秋冬季唐山市PM 2.5中元素组成特征及来源解析

Characterization of Elemental Compositions and Their Sources of PM 2.5 in Tangshan City in Autumn and Winter from 2017 to 2018

为研究唐山市大气PM 2.5中元素组成特征及其来源,于2017年10月19日—2018年1月31日(秋冬季)在唐山市的超级站(典型城市站点)、开平站(工业站点)和古冶站(工业站点)开展了PM 2.5的手工连续采样,定量分析测定了PM 2.5中23种无机元素.结果表明:Si、Al、Ca和Na等地壳元素的质量浓度均在10月最高,在1月最低.10月,ρ(Cr)在开平站最高(0.0200μg/m 3),随后逐月略微降低,其主要受钢铁冶炼工业的减产和限产影响.多数重金属元素质量浓度在11月或12月最高,包括Zn、Pb、Mn、Cu、Ni、Se、V、Cd和Co,其可能受燃煤取暖影响.Cd、Zn、Pb和Cu四种元素的富集因子值分别为2677、616、422和77,均达到极强富集,且均受人为排放源影响最大.基于因子分析法得出,唐山市大气PM 2.5中元素的主要来源有燃煤源、钢铁工业源与扬尘源的混合源、交通源以及土壤扬尘源,其方差贡献率分别为56.3%、21.6%、7.1%、5.4%.研究显示,秋冬季唐山市大气颗粒物PM 2.5中元素最主要的污染来源为工业源、燃煤源和扬尘源.

Continuous manual sampling of PM 2.5 was carried out at Super site(typical urban site),Kaiping site and Guye site(typical industrial site)in Tangshan City from October 19 th,2017 to January 31 st,2018(autumn-winter season),and the 23 selected inorganic elements was quantitatively analyzed.The compositions and sources of PM 2.5 elements in the atmosphere of Tangshan City were studied.The results show that the mass concentrations of the crustal elements,such as Si,Al,Ca and Na,all showed the highest characteristics in October but the lowest in January.The monthly concentrations of Cr were the highest level at Kaiping site(0.0200μg /m 3)in October,and then it slightly decreased month by month,which was mainly affected by the reduction and limitation of steel production of the local steel smelting industries.The concentrations of most heavy metals,including Zn,Pb,Mn,Cu,Ni,Se,V,Cd and Co,were high in November or December,which suggests the significant impact of coal-combustion heating.The enrichment factors of Cd,Zn,Pb and Cu reached up to 2677,616,422 and 77,respectively,and the extremely strong enrichment implied a strong effect of anthropogenic emissions.Based on the factor analysis,the main sources of PM 2.5 elements in the atmosphere of Tangshan City are the coal-combustion source,mixed source of iron steel industry emissions and re-suspended dust,transportation emission source and the soil dust source;and their contribution rates to the variance were 56.3%,21.6%,7.1%and 5.4%,respectively.Therefore,the elements of atmospheric PM 2.5 of Tangshan City are mainly from coal combustion,industry and dust.