Molecular Composition of Anthropogenic Oxygenated Organic Molecules and Their Contribution to Organic Aerosol in a Coastal City

Environmental Science & Technology, Год журнала: 2023, Номер 57(42), С. 15956 - 15967

Опубликована: Окт. 16, 2023

Organic aerosols (OA) have gained attention as a substantial component of atmospheric owing to their impact on visibility, climate, and human health. Although oxygenated organic molecules (OOMs) are essential contributors OA formation, the sources, transformations, fates OOMs not fully understood. Herein, anthropogenic (AOOMs), volatile compounds (AVOCs), were concurrently measured in Xiamen, coastal city southeastern China. Our results show that AOOMs exhibited high nitrogen content (76%) low oxidation degree. Strong photochemical processes aromatic VOCs predominant sources AOOMs. Also, NOx concentrations occurrence multigeneration OH radical oxidations critical factors might influence formation Finally, newly developed aerosol dynamic model's more than 35% mass growth rate is attributed gas-particle partitioning Further sensitivity testing demonstrates contribution significantly enhanced during high-particulate-concentration periods, especially under low-temperature conditions. This study emphasizes vital role photochemically produced derived from AVOCs urban atmosphere.

Язык: Английский

Modeling the Formation of Organic Compounds across Full Volatility Ranges and Their Contribution to Nanoparticle Growth in a Polluted Atmosphere

Environmental Science & Technology, Год журнала: 2023, Номер 58(2), С. 1223 - 1235

Опубликована: Дек. 20, 2023

Nanoparticle growth influences atmospheric particles' climatic effects, and it is largely driven by low-volatility organic vapors. However, the magnitude mechanism of organics' contribution to nanoparticle in polluted environments remain unclear because current observations models cannot capture organics across full volatility ranges or track their formation chemistry. Here, we develop a mechanistic model that characterizes spectrum vapors contributions coupling advanced oxidation modeling kinetic gas-particle partitioning. The applied Nanjing, typical city, effectively captures distribution (with saturation vapor concentrations <0.3 μg/m3), thus accurately reproducing rates (GRs), with 4.91% normalized mean bias. Simulations indicate as particles grow from 4 40 nm, relative fractions GRs attributable increase 59 86%, remaining H2SO4 its clusters. Aromatics contribute much condensable (∼37%), especially (∼61%), contributing most (32–46%) 4–40 nm grow. Alkanes also 19–35% GRs, while biogenic volatile compounds minimally (<13%). Our helps assess impacts predict future changes.

Язык: Английский