Atmospheric iron deposition in a megacity of northwest China: Solubility, speciation, and deposition fluxes--颗粒学报PARTICUOLOGY

Yang, X., Liu, P., Xue, Z., Zhang, H., Li, X., Xu, H., & Shen, Z. (2024). Atmospheric iron deposition in a megacity of northwest China: Solubility, speciation, and deposition fluxes. Particuology, 90, 383-393. https://doi.org/10.1016/j.partic.2023.10.015

Atmospheric iron deposition in a megacity of northwest China: Solubility, speciation, and deposition fluxes

Xiaotao Yang^a, Pingping Liu^{a b *}, Zhiwei Xue ^c, Hao Zhang ^a, Xuan Li ^d, Hongmei Xu^{a b *}, Zhenxing Shen ^a

a Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an, China
b State Key Laboratory of Loess and Quaternary National Key R&D of China Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
c No. 203 Research Institute of Nuclear Industry, Xi'an, 710086, China
d Xi'an Environmental Monitoring Station, Xi'an 710054, China

10.1016/j.partic.2023.10.015

Volume 90, July 2024, Pages 383-393

Received 20 September 2023, Revised 31 October 2023, Accepted 31 October 2023, Available online 14 November 2023, Version of Record 8 February 2024.

E-mail: liupingping@xjtu.edu.cn; xuhongmei@xjtu.edu.cn

Highlights

• The content of total Fe and water-soluble (ws)-Fe levels were the highest in spring and winter respectively.

• Ws-Fe (II) was the dominant chemical form of ws-Fe.

• Crustal dust contributed mainly to total Fe, while biomass burning controlled peak values of ws-Fe.

• Industrial areas had the highest total Fe, ws-Fe, and Fe deposition fluxes.

Abstract

Atmospheric iron has crucial effects on biogeochemical cycles, atmospheric processing, global climate, and human health. In this study, atmospheric dustfall samples were collected from six functional areas in Xi'an, China, from 2020 to 2021. The spatiotemporal distributions and deposition fluxes of total and water-soluble (ws) Fe as well as the speciation and potential sources of ws-Fe were characterized. Industrial areas had the highest concentrations of total Fe and ws-Fe, which were mainly due to copious emissions of heavy metals during manufacturing. The total Fe concentrations peaked in spring, primarily due to the substantial input of crustal dust, which also led to the lowest Fe solubility in this season. By contrast, the highest levels of ws-Fe occurred during winter due to an increase in biomass combustion. Among the water-soluble forms, ws-Fe (II) was dominant and accounted for 74.8% of the total amount of ws-Fe. Crustal dust was the main contributor to total Fe, whereas biomass burning primarily contributed to peak ws-Fe concentrations. The average total and ws-Fe deposition fluxes in Xi'an were the highest in spring and lowest in autumn, which were related to the distributions of the dustfall deposition fluxes and their Fe contents during these periods. Our study provided a broader and comprehensive understanding of atmospheric iron deposition in Chinese urban area, which is of positive significance for understanding atmospheric chemistry and global climate change.

Graphical abstract

Keywords

Atmospheric dustfall; Iron; Speciation distribution; Seasonal variation; Functional area; Sources

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