Comparative analysis of winter composite-PM2.5 in Central Indo Gangetic Plain cities: Combined organic and inorganic source apportionment and characterization, with a focus on the photochemical age effect on secondary organic aerosol formation

被引：1

作者：

Akanksha ^{[1
]}

Shukla, Ashutosh Kumar ^{[1
]}

Bhowmik, Himadri Sekhar ^{[1
]}

Yadav, Amit Kumar ^{[1
]}

Jain, Vaishali ^{[1
]}

Murari, Vishnu ^{[1
,3
]}

Gaddamidi, Sreenivas ^{[1
,4
]}

Lalchandani, Vipul ^{[1
,5
]}

Tripathi, Sachchida Nand ^{[1
,2
]}

机构：

[1] Indian Inst Technol Kanpur, Dept Civil Engn, Kanpur, India

[2] Indian Inst Technol, Dept Sustainable Energy Engn, Kanpur, India

[3] Inst Mines Telecom IMT Nord, 941 rue Charles Bourseul, F-59508 Douai, France

[4] Indian Inst Trop Meteorol, Ctr Climate Change Res, Pune, Maharashtra, India

[5] Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham, England

来源：

ATMOSPHERIC ENVIRONMENT | 2024年 / 338卷

关键词：

Central IGP; Source apportionment; Inorganic-rich factors; Biomass burning; SOA; Photochemical age; REAL-TIME MEASUREMENTS; HIGH-RESOLUTION; MASS-SPECTROMETER; BLACK CARBON; CHEMICAL-CHARACTERIZATION; ESTIMATING UNCERTAINTY; PM2.5; AEROSOL; CITY SOURCES; EVOLUTION; PARTICLES;

D O I：

10.1016/j.atmosenv.2024.120827

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

To gain insights into air quality dynamics, a high-end instrument such as High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) alongside an Aethalometer was used to measure the Composite PM2.5 (C-PM2.5) in Lucknow and Kanpur during winter. It encompasses non-refractive PM2.5 (NR-PM2.5) and Black Carbon (BC) mass concentrations. Significant variation was noted in average C-PM2.5 concentrations at both sites, as 168.8 +/- 61.3 mu g m(-3) in Lucknow and 90.7 +/- 25.7 mu g m(-3) in Kanpur. Organics emerged as the predominant component, constituting similar to 55%-65% of the C-PM2.5 mass, followed by inorganics (24% and 30%) and BC (20% and 8%). The present study employs Positive Matrix Factorization (PMF) on combined organic and inorganic source apportionment, resolving eight and seven source factors at Lucknow and Kanpur, respectively. Both sites exhibit significant contributions from solid-fuel combustion organic aerosol (SFC-OA), with similar to 11% in Lucknow and 8% in Kanpur. However, SFC-OA mass concentration in Lucknow, at 24.67 mu g m(-)(3), is nearly double that in Kanpur (12.05 mu g m(-)(3)). This was likely due to domestic coal burning in the nearby households, unregulated open burning, and burning of garbage on roadsides. The study shows that both sites were affected by oxidized biomass burning OA (O-BBOA) emissions, with increased concentration during the night due to dark oxidation by NO3 radicals. The diurnal variation of secondary organic aerosols (SOA), such as O-BBOA and semi-volatile oxygenated OA (SVOOA), shows increasing concentration during daytime hours. Therefore, the photochemical aging (t(a)) role in SOA formation was analyzed, and it was revealed that the formation might primarily be driven by photochemical oxidation. Additionally, two inorganic-rich factors, sulfate and nitrate-related OA (SO4-OA and NO3-OA) at both sites and additional ammonium chloride-related OA (NH4Cl-OA) resolved at Lucknow. Our study shows that NO3-OA and SO4-OA formation was dominated by aqueous phase processes due to high relative humidity and decline in concentration with increasing t(a) (t(a) > 30 h) during winter.

引用

页数：17