Realtime chemical characterization of post monsoon organic aerosols in a polluted urban city: Sources, composition, and comparison with other seasons
| Autor: | Abhishek Chakraborty, Anil Kumar Mandariya, Sachchida Nand Tripathi, Tarun Gupta, Ruparati Chakraborti |
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| Rok vydání: | 2018 |
| Předmět: |
010504 meteorology & atmospheric sciences
Meteorology Health Toxicology and Mutagenesis Air pollution India 010501 environmental sciences Toxicology medicine.disease_cause 01 natural sciences Mass Spectrometry chemistry.chemical_compound Air pollutants Air Pollution medicine Dominance (ecology) Cities Sulfate 0105 earth and related environmental sciences Aerosols Air Pollutants Sulfates High loading General Medicine Pollution Aerosol chemistry Post monsoon Environmental chemistry Atmospheric chemistry Environmental science Seasons Environmental Monitoring |
| Zdroj: | Environmental Pollution. 232:310-321 |
| ISSN: | 0269-7491 |
| Popis: | Real time chemical characterization of non-refractory submicron aerosols (NR-PM1) was carried out during post monsoon (September-October) via Aerosol Mass Spectrometer (AMS) at a polluted urban location of Kanpur, India. Organic aerosol (OA) was found to be the dominant species with 58% contribution to total NR-PM1 mass, followed by sulfate (16%). Overall, OA was highly oxidized (average O/C = 0.66) with the dominance of oxidized OAs (60% of total OA) as revealed by source apportionment. Oxidized nature of OA was also supported by very high OC/EC ratios (average = 8.2) obtained from simultaneous offline filter sampling. High and low OA loading periods have very dramatic effects on OA composition and oxidation. OA O/C ratios during lower OA loading periods were on average 30% higher than the same from high loading periods with significant changes in types and relative contribution from oxidized OAs (OOA). Comparison of OA sources and chemistry among post monsoon and other seasons revealed significant differences. Characteristics of primary OAs remain very similar, but features of OOAs showed substantial changes from one season to another. Winter had lowest OOA contribution to total OA but similar overall O/C ratios as other seasons. This reveals that processing of primary OAs, local atmospheric chemistry, and regional contributions can significantly alter OA characteristics from one season to another. This study provides interesting insights into the seasonal variations of OA sources and evolution in a very polluted and complex environment. |
| Databáze: | OpenAIRE |
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