In-cloud formation of secondary species in iron-containing particles
In-cloud formation of secondary species in iron-containing particles
复制标题
含铁颗粒中次要物种的云内形成
DOI：
10.5194/acp-19-1195-2019
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发表时间：
2019-01-30
影响因子：
6.3
通讯作者：
Zhou, Zhen
中科院分区：
文献类型：
--
作者：
Lin, Qinhao;Bi, Xinhui;Zhou, Zhen
抽象。通过云处理的次生物种的增加可能
增加气溶胶铁（Fe）的生物利用度。在这项研究中，
与实时单粒子气溶胶耦合的逆流虚拟撞击器
质谱仪用于表征次级物种的形成
在一个山区的含铁云残留物（干燥的云滴）中，
在2016年秋季，中国南部地区持续了近1个月。富铁，
铁尘、铁元素碳（Fe-EC）和铁钒（Fe-V）云残留
在这项研究中获得的类型。富铁颗粒，与
燃烧源，占84%（按数量）的含铁
云残留物和铁尘颗粒占12%。其余
4%由Fe-EC和Fe-V颗粒组成。据发现，上述
90%（按数量计）的含Fe颗粒已经含有硫酸盐
在云事件之前，导致云的数量分数（NF）没有明显的变化，
在云事件中。云处理有助于增强NF
硝酸盐、氯化物和草酸盐在含铁云残留物。
然而，在富铁型中，
相对于铁尘型不太明显。草酸根的NF增加，
富铁云渣是由草酸盐水溶液氧化生成的
前体（例如，乙醛酸酯）。此外，Fe驱动的芬顿反应可能
增加水相OH的生成速率，提高了
富铁云残留物中草酸盐的前体。白天，
在富铁云残留物中草酸盐的NF降低被认为是由于
草酸铁络合物的光解。这项工作强调的作用，
燃烧铁源参与云处理，具有重要的
评价燃烧源中Fe生物利用度的意义
云处理
Abstract. The increase in secondary species through cloud processing potentially
increases aerosol iron (Fe) bioavailability. In this study, a ground-based
counterflow virtual impactor coupled with a real-time single-particle aerosol
mass spectrometer was used to characterize the formation of secondary species
in Fe-containing cloud residues (dried cloud droplets) at a mountain site in
southern China for nearly 1 month during the autumn of 2016. Fe-rich,
Fe-dust, Fe-elemental carbon (Fe-EC), and Fe-vanadium (Fe-V) cloud residual
types were obtained in this study. The Fe-rich particles, related to
combustion sources, contributed 84 % (by number) to the Fe-containing
cloud residues, and the Fe-dust particles represented 12 %. The remaining
4 % consisted of the Fe-EC and Fe-V particles. It was found that above
90 % (by number) of Fe-containing particles had already contained sulfate
before cloud events, leading to no distinct change in number fraction (NF) of
sulfate during cloud events. Cloud processing contributed to the enhanced NFs
of nitrate, chloride, and oxalate in the Fe-containing cloud residues.
However, the in-cloud formation of nitrate and chloride in the Fe-rich type
was less obvious relative to the Fe-dust type. The increased NF of oxalate in
the Fe-rich cloud residues was produced via aqueous oxidation of oxalate
precursors (e.g., glyoxylate). Moreover, Fe-driven Fenton reactions likely
increase the formation rate of aqueous-phase OH, improving the conversion of
the precursors to oxalate in the Fe-rich cloud residues. During daytime, the
decreased NF of oxalate in the Fe-rich cloud residues was supposed to be due
to the photolysis of Fe-oxalate complexes. This work emphasizes the role of
combustion Fe sources in participating in cloud processing and has important
implications for evaluating Fe bioavailability from combustion sources during
cloud processing.