Microscopic evaluation of trace metals in cloud droplets in an acid precipitation region.
Microscopic evaluation of trace metals in cloud droplets in an acid precipitation region.
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DOI：
10.1021/es304779t
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发表时间：
2013-04
影响因子：
11.4
通讯作者：
Weijun Li;Yan Wang;J. Collett;Jianmin Chen;Xiaoye Zhang;Zifa Wang;Wen-xing Wang
中科院分区：
文献类型：
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作者：
Weijun Li;Yan Wang;J. Collett;Jianmin Chen;Xiaoye Zhang;Zifa Wang;Wen-xing Wang
云中可溶性痕量金属的质量浓度和纳米金属颗粒的大小、数量和混合特性决定了它们对生态系统的毒性。云水被发现是酸性的，pH值为3.52，在山。鲁（海拔1，165米）位于中国南方的一个酸性降水区。电感耦合等离子体质谱（ICPMS）和透射电子显微镜（TEM）的组合首次表明，可溶性金属浓度和固体金属颗粒数是令人惊讶的高酸性云在山。Lu，其中SO2、NO2和PM10的日浓度分别为18 μg m（-3）、7 μg m（-3）和22 μg m（-3）。云水中浓度最高的可溶性金属是锌（Zn，200 μg L（-1））、铁（Fe，88 μg L（-1））和铅（Pb，77 μg L（-1））。TEM显示76%的云残留物包括直径从50 nm到1 μm的金属颗粒，中值直径为250 nm。四种主要的金属伴生颗粒类型是富Pb（35%）、粉煤灰（27%）、富Fe（23%）和富Zn（15%）。元素分布图表明，可溶性微量金属分布在云残留物的硫酸盐中。来自大型有色金属工业和燃煤发电厂的排放物被向上输送到这个高海拔地区。结果表明，云中丰富的微量金属元素加剧了酸性云或相关降水对生态系统和人类健康的影响。
Mass concentrations of soluble trace metals and size, number, and mixing properties of nanometal particles in clouds determine their toxicity to ecosystems. Cloud water was found to be acidic, with a pH of 3.52, at Mt. Lu (elevation 1,165 m) in an acid precipitation region in South China. A combination of Inductively Coupled Plasma Mass Spectrometry (ICPMS) and Transmission Electron Microscopy (TEM) for the first time demonstrates that the soluble metal concentrations and solid metal particle number are surprisingly high in acid clouds at Mt. Lu, where daily concentrations of SO2, NO2, and PM10 are 18 μg m(-3), 7 μg m(-3), and 22 μg m(-3). The soluble metals in cloudwater with the highest concentrations were zinc (Zn, 200 μg L(-1)), iron (Fe, 88 μg L(-1)), and lead (Pb, 77 μg L(-1)). TEM reveals that 76% of cloud residues include metal particles that range from 50 nm to 1 μm diameter with a median diameter of 250 nm. Four major metal-associated particle types are Pb-rich (35%), fly ash (27%), Fe-rich (23%), and Zn-rich (15%). Elemental mapping shows that minor soluble metals are distributed within sulfates of cloud residues. Emissions of fine metal particles from large, nonferrous industries and coal-fired power plants with tall stacks were transported upward to this high elevation. Our results suggest that the abundant trace metals in clouds aggravate the impacts of acid clouds or associated precipitation on the ecosystem and human health.