| Title: | Smog chamber study of the role of NH(3) in new particle formation from photo-oxidation of aromatic hydrocarbons |
| Author(s): | Li K; Chen L; White SJ; Yu H; Wu X; Gao X; Azzi M; Cen K; |
| Address: | "State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China; CSIRO Energy, PO Box 52, North Ryde, NSW 1670, Australia. State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: chenlh@zju.edu.cn. CSIRO Energy, PO Box 52, North Ryde, NSW 1670, Australia. Electronic address: Stephen.J.White@csiro.au. CSIRO Energy, 10 Murray Dwyer Circuit, Mayfield West, NSW 2304, Australia. State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. CSIRO Energy, PO Box 52, North Ryde, NSW 1670, Australia" |
| DOI: | 10.1016/j.scitotenv.2017.11.180 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Linking) |
| Abstract: | "Ammonia (NH(3)) is a major contributor to secondary aerosol in the atmosphere and can alter the kinetics of their formation. However, systematic studies related to the role of NH(3) in aerosol nucleation processes and further particle size growth under complex scenarios are lacking. In this study, we conducted 16 experiments in the CSIRO smog chamber under dry conditions using aromatic hydrocarbons (toluene, o-/m-/p-xylene) and different concentrations of NH(3). The presence of NH(3) did not change the gas-phase chemistry or nucleation onset time, but slowed the nucleation rate (5%-94%) once it began. From the response of nitrogen oxides (NOx) measurement and mechanism modeling results, we hypothesised that the surface reaction between NH(3) and nitric acid played a central role in aerosol nucleation and further growth. After nucleation, the subsequently formed ammonium nitrate and organic condensation vapours may partition together into the initial growth process of new particles, thus increasing the aerosol initial growth rate (8%-90%) and size growth potentials (7%-108%), and leading to high aerosol mass formation. Further investigation implied that the initial growth and further growth rate determine the aerosol mass concentration, rather than the nucleation rate. We conclude that both the initial NOx concentration and volatile organic compound (VOC)/NOx ratio are crucial for the initial and further growth, and aerosol mass of new particles, when NH(3) levels are high. Our results provide crucial insights into the complex chemistry of VOC/NOx/NH(3) in the atmosphere, and highlight the importance of NH(3) reduction for particulate matter control" |
| Keywords: | Growth rate Nh(3) Nucleation Soa Smog chamber; |
| Notes: | "PubMed-not-MEDLINELi, Kangwei Chen, Linghong White, Stephen J Yu, Hai Wu, Xuecheng Gao, Xiang Azzi, Merched Cen, Kefa eng Netherlands 2018/05/08 Sci Total Environ. 2018 Apr 1; 619-620:927-937. doi: 10.1016/j.scitotenv.2017.11.180. Epub 2017 Nov 29" |
