Assessing the influence of environmental conditions on secondary organic aerosol formation from a typical biomass burning compound
Lin Du , Xiaotong Jiang , Dantong Liu , Li Xu , Narcisse T. Tsona , Maofa Ge , Yujing Mu , Jianmin Chen , Min Shao , Zifa Wang
DOI:10.1016/j.jes.2021.08.016
Received May 30, 2021,Revised , Accepted August 02, 2021, Available online January 15, 2022
Volume 34,2022,Pages 136-148
The atmospheric chemistry in complex air pollution remains poorly understood. In order to probe how environmental conditions can impact the secondary organic aerosol (SOA) formation from biomass burning emissions, we investigated the photooxidation of 2,5-dimethylfuran (DMF) under different environmental conditions in a smog chamber. It was found that SO2 could promote the formation of SOA and increase the amounts of inorganic salts produced during the photooxidation. The formation rate of SOA and the corresponding SOA mass concentration increased gradually with the increasing DMF/OH ratio. The addition of (NH4)2SO4 seed aerosol accelerated the SOA formation rate and significantly shortened the time for the reaction to reach equilibrium. Additionally, a relatively high illumination intensity promoted the formation of OH radicals and, correspondingly, enhanced the photooxidation of DMF. However, the enhancement of light intensity accelerated the aging of SOA, which led to a gradual decrease of the SOA mass concentration. This work shows that by having varying influence on atmospheric chemical reactions, the same environmental factor can affect SOA formation in different ways. The present study is helpful for us to better understand atmospheric complex pollution.
