Sources identification of ammonium in PM 2.5 during monsoon season in Dhaka, Bangladesh.

Autor: Kawashima H; Department of Management Science and Engineering, Faculty of Systems Science & Technology, Akita Prefectural University, 015-0055 Akita, Japan. Electronic address: kawashima@akita-pu.ac.jp., Yoshida O; Department of Management Science and Engineering, Faculty of Systems Science & Technology, Akita Prefectural University, 015-0055 Akita, Japan., Joy KS; Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka 1000, Bangladesh., Raju RA; Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka 1000, Bangladesh., Islam KN; Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka 1000, Bangladesh., Jeba F; Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka 1000, Bangladesh., Salam A; Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka 1000, Bangladesh.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Sep 10; Vol. 838 (Pt 3), pp. 156433. Date of Electronic Publication: 2022 Jun 02.
DOI: 10.1016/j.scitotenv.2022.156433
Abstrakt: Ammonia (NH 3 ) is taken up by fine particulate matter (PM 2.5 ), and there are concerns about its impact on the environment and health. The source of NH 3 , which was thought to be of agricultural sources, has recently been suspected to be non-agricultural sources in urban areas. Here, we collected PM 2.5 during the monsoon season in Dhaka, Bangladesh, the most polluted city in the world, and analyzed the δ 15 N-NH 4 + in PM 2.5 . As the result, the δ 15 N-NH 4 + ranged from 9.2 ‰ to 34.4 ‰ (average: 20.7 ± 4.8 ‰), the highest of any of the averaged values annual reported in previous researches. In order to perform source analysis, the NH 3 concentrations were estimated using the thermodynamic model ISORROPIA-II. The estimated concentration of NH 3 gas averaged 40.8 μg/m 3 (3.0-154.6 μg/m 3 ). The contributions calculated with the mixing model to the δ 15 N-NH 4 + values in PM 2.5 in Dhaka, Bangladesh averaged 25.3 ± 14 %, 22.8 ± 10 %, 26.5 ± 15 %, and 25.4 ± 10 % for waste, fertilizer, NH 3 slip, and fossil fuel combustion, respectively. Non-agricultural sources (NH 3 slip, and fossil fuel combustion) accounted for almost half (51.9 %) of the contributions. In addition, the several validation tests of the isotope mixing model were also performed. For validating the uncorrected and corrected source data for δ 15 N-NH 3 , the contribution of non-agricultural sources with uncorrected source data would have been very high (>80 %), much higher than the corrected source data.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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