Physicochemical Characterization of Air Pollution Particulate Matter (PM2.5 and PM>2.5) in an Urban Area of Cotonou, Benin
Résumé
PM 2.5 and PM >2.5 samples were collected in Cotonou (Benin) using high volume cascade impaction air samplers. The samplings were based on continuous collection over twelve days. Physical and chemical characteristics of samples were determined by size distribution (laser granulometry), specific surface areas (BET method), inorganic elements (ICP-MS), water-soluble ions (IC), CHNS analysis and organic compounds (GC-MS). Average concentrations of air particulate matter were 180.9 µg/m 3 and 94.5 µg/m 3 in PM 2.5 and PM >2.5 , respectively. The higher water-soluble ions recorded were Ca 2+ ,SO 4 2− ,NO 3 − , Na + and Cl − for both PM. Moreover, concentrations were almost twofold higher for PM 2.5 compared to PM >2.5 , with 10.7 µg/m 3 of total metals found in PM 2.5 versus 5.6 µg/m 3 in PM >2.5. Both PM samples under study presented similar repartition of elements considering their percentages. Results suggested that PM >2.5 samples contain agglomerates of fine particles. Identification tools of major pollution source as inorganic elements, paraffins, fatty acids ratios and PAHs ratios indicated that PM under study originated from traffic exhaust.
| Origine | Publication financée par une institution |
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| Licence |
Domaine public
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