Aerosol particles with NaCl-inlay in coastal haze-fog episodes

AbstractThe NaCl-containing aerosol particles (NaCl-containing APs) are trapped in the coastal atmosphere, in which sodium chloride and other salt compounds, such as calcium sulfate and ammonium nitrate, form a core –shell composite structure. The excessive anthropogenic emissions of pollutants, such as SO2, NOx, NH3, and construction dust, as well as salt spray, provide the material supply, and the low wind speed, humid, and hot weather environment creates incubators for these indigenous NaCl-containing APs. They are easy to form in coastal haze-fog episodes, even accounting for about 45% of all haze APs. A homemade aerosol particle simulative generator (APSG, patent authorization ZL 2018 1 0,516,861.3) was designed to explore the formation mechanism of NaCl-containing APs, which provides an effective research platform for simulating the evolution of particle structure in natural environment. The simulated experiments carried out on the APSG have successfully bred the artificial NaCl-containing APs and the carbonate/sulfate core –shell structure with different carbonate transformation degrees. The evolution of carbonate/sulfate core–shell structure provides solid evidence for the oxidation of S(IV) by dissolved NOx to sulfate (SO42 −). Then, the strong acid in the salt drop reacts with carbonate through metathesis reaction to form sulfate and nitrate. With the volatilization of the salt drop, sulfate and nitrate crystallize and precipitate successively to form a comp...
Source: Air Quality, Atmosphere and Health - Category: Environmental Health Source Type: research