Elemental profiles and signatures of fugitive dusts from Chinese deserts

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• 作者：Rong Zhang ; Junji Cao ; Yanrong Tang ; Richard Arimoto ; Zhenxing Shen ; Feng Wu ; Yongming Han ; Gehui Wang ; Jiaquan Zhang ; Guohui Li
• 关键词：Elemental profiles ; Chinese deserts ; Asian dust ; Source signatures
• 刊名：Science of the Total Environment
• 出版年：15 February, 2014
• 年：2014
• 卷：472
• 期：Complete
• 页码：1121-1129
• 全文大小：1186 K

文摘

Elemental profiles were determined for size-separated fugitive dust particles produced from Chinese desert and gobi soils. Seventeen surface soil samples from six Chinese deserts were collected, composited, resuspended, and sampled through TSP, PM₁₀, and PM_2.5 inlets onto Teflon庐 filters, which were analyzed for twenty-six elements. Two major dust sources could be distinguished based on differences in crustal and enriched elements鈥攖he northwestern (NW) region (Taklimakan Desert, Xinjiang Gobi, and Anxinan Gobi) and northern (N) region (Ulan Buh Desert, Central Inner Mongolia Desert, and Erenhot Gobi). The N sources showed lower concentrations of mineral elements (Fe, K, Na, Ti, Mn, Cr, and Rb in PM₁₀, and Fe, K, Ti, Mn, Co, and V in PM_2.5) and higher levels of contaminants (S, Zn, Mo, Cu, Cr, Pb, Cd, and As) than the NW ones, especially in PM_2.5. Enrichment factors for Cu, Cr, Zn, Pb, As, Mo, and Cd calculated relative to the upper continental crust showed enrichments of one to two orders-of-magnitude, and they were much higher for N sources than NW ones, implying stronger anthropogenic impacts in north China. Aerosol elemental concentrations during dust events at Horqin, Beijing, and Xi'an matched the mass percentages of mineral elements from their presumptive sources better than the alternative ones, validating the differences between the NW and N sources. Additionally, Na/S, Mg/S, Fe/Al, K/Al, Si/Fe, and Na/Al ratios were suggested to differentiate the two dust source regions. The elemental ratios of Ca/Al, K/Al, Fe/Al, and Ti/Fe in the source regions matched those in aerosols collected downwind, and they can be considered as possible source indicators.