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The mixing state of mineral dusts with typical anthropogenic pollutants: A mechanism study

Author:
Ji, Yuemeng, Chen, Xingyu, Li, Yixin, Zhang, Weina, Shi, Qiuju, Chen, Jiangyao, Gao, Yanpeng, Li, Guiying, Wang, Jiaxin, Tian, Pengfei, An, Taicheng
Source:
Atmospheric environment 2019 v.209 pp. 192-200
ISSN:
1352-2310
Subject:
acrolein, aerosols, atmospheric chemistry, climate, dust, hydrogen bonding, industrialization, mixing, nitrogen oxides, phase transition, pollutants, radiative forcing, reaction mechanisms, silica, sulfur oxides, urbanization
Abstract:
The particle mixing state is a key feature in determining their role in the earth system, exerting a substantial impact on radiative forcing and climate. However, the mechanism of particle mixing reactions is unclear, especially for the mixing of mineral dusts with anthropogenic pollutants (APs). In this study, the mixing reaction mechanisms of typical APs (acrolein, SOx, and NOx) with mineral dust (SiO2) were investigated by using theoretical approach. The mixing ability of SiO2 with inorganic compounds mainly depends on the strength of the interaction of the center atom of inorganic compounds and the surface of SiO2, while SiO2 mixed with acrolein (ARL) proceeds via only hydrogen bonding (HB). The nucleation ability of SiO2 is enhanced significantly from simultaneous existence of ARL and SOx/NOx. SiO2 exhibits a high reactivity with SO3 and acrolein (ARL), proceeding an irreversible process. The mixing reactions of SO2/NOx and SiO2 are reversible, but the binding is enhanced by ARL, which contributes to the dust aerosol nucleation process by binding to SO2/NOx and SiO2. The charge density difference and natural bond orbital analysis show that organic compound acts as both hydrogen bonding (HB) donors and acceptors, while inorganic compound is only HB acceptor. Our results reveal that the mixing state of mineral dust with anthropogenic pollutant is largely facilitated in area with rapid industrialization and urbanization, which could further influence climate and radiative forcing.
Agid:
6380830