In-situ measurement of secondary aerosol formation potential using a flow reactor: Livestock agricultural area. (15th May 2023)

• Record Type: Journal Article
• Authors: Ashraf, Fawad; Ali, Ahsan; Park, Jun-Hyun; Kim, Joonwoo; Park, Kihong; Lim, Ho-Jin
• Is Part Of: Atmospheric environment. Volume 301(2023)
• Publication Date: 2023-05-15
• Subjects: PM2.5 -- Secondary organic aerosol -- Aerosol formation potential -- NH3 -- Livestock farming -- ACSM; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2023.119695
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: Atmospheric ammonia (NH3 ) is an important particulate matter (PM) precursor. The primary sources of ammonia in agriculture are livestock farming and synthetic fertilizers. Here, an oxidation flow reactor (OFR) was deployed in the vicinity of livestock farming during the summer of 2020 and winter of 2021 to determine the extent of secondary aerosol formation. The OFR was run in a 1-h cycle of different aging times for the daytime and nighttime oxidants of OH and NO3 radicals, respectively. The daytime reaction periods were 05:00–20:00 and 08:00–18:00, respectively, for summer and winter. Ambient and aged PM2.5 were characterized for secondary aerosol formation potential (AFP) using a time-of-flight aerosol chemical speciation monitor (ToF-ACSM). Ambient PM2.5 mean composition during summer was dominated in the order of nitrate (41%), organic matter (33%), ammonium (15%), and sulfate (11%). Secondary AFP was in the higher order, nitrate (71%), ammonium (20%), organic matter (8%), and sulfate (1%). A prominent effect of NH3 was observed when the primary aerosol was aged at high NOx and relative humidity (RH). Source apportionment revealed secondary organic aerosol (SOA)-dominant organic aerosols. Graphical abstract: Image 1 Highlights: PM2.5 and its control factors were characterized in the livestock farming area. PM2.5 was dominated by NO3 −, followed by OM, NH4 +, and SO4 2− in the abundance of NH3 . Oxidation in OFR enhanced PM2.5 substantially for NO3 − and NH4 + and slightly for SOA. OA source apportionment showed SOA dominated pattern for the campaigns. A higher ε (NO3) resulted in a decrease in aerosol acidity and an increase in AWC.