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Size-segregated trace elements and water-soluble ions in Moscow airborne particulate matterтезисы доклада
- Авторы: Tositti L., Popovicheva O., Zappi A., Chichaeva M., Kovach R., Minkina T., Kasimov N.
- Сборник: European Aerosol Conference 2023 (EAC2023)
- Тезисы
- Год издания: 2023
- Место издания: Malaga
- Первая страница: Poster−1: 2.11#17
- Аннотация: Since inhalation is dependent on particle size, atmospheric particulate matter (PM) fractions as well as detailed size-fractionated characterization of inorganic particles in PM is of great interest (Eleftheriadis et al., 2014). In this respect, megacities such as Moscow with over ten million inhabitants require a special focus. We present the results of the ongoing investigations aiming at an in-depth characterization of Moscow PM, based on the determination of trace elements (TE) and ionic fraction profiles both in PM10 and in size-segregated aerosol samples. As a northern latitude megacity, this type of investigation is expected to fill fundamental gaps in the understanding of atmospheric dynamics in such a peculiar urban landscape, wherein systematic and up-to-date studies, started to be implemented. Two sampling campaigns have been performed at the Aerosol Complex of Moscow State University at southwest of Moscow, classified as urban background site, the first one from April 2018 to December 2019, and the second one from September 2021 to August 2022. PM filters have been collected with a MOUDI impactor, then analyzed by ion chromatography (IC), proton-induced X-ray emission (PIXE), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). All these methods are well-suited to size-resolved elemental and ionic speciation of atmospheric aerosols. Correlations between TE and ions were evaluated, in conjunction with meteorological data, and chemometric analyses were carried out to shed light at a higher degree of detail on aerosol sources, environmental fate and health hazards in Moscow megacity airshed. First results on ionic fraction (Zappi et al. 2023) evidenced a strong seasonality of pollution, mainly due to the peculiar climate of that area, characterized by snowfall starting early in October and that go on until March. Massive contribution of measured species to PM10 for each season is shown in Fig.1. Total inorganic ions (TII) constitute the largest fraction of aerosol mass in the cold period reaching a maximum of 27% in autumn, and a minimum of 16.5% in summer. Sulfates and nitrates dominate among the major anion components, with maximum contribution of 38 and 34% to TII in autumn. Cations are mainly represented by calcium and ammonium. Ca2+ had a maximum of 21% in spring and minimum of 5% in autumn. Ca2+ and Mg2+ relate to local soil resuspension after snow thaw, Ca2+ shows an additional source from intensive building activities in the New Moscow area. Seasonality of NH4 + was not prominent, being 15-17% in any season. A lower, though significant, fraction of inorganic ions in TII was represented by sodium and chloride; in summer the percentage of both Cl- and Na+ approached their maxima respectively of 5 and 11%, probably due to resuspension of technical salt used for road management during snowing periods (confirmations are expected from TE and EDX analysis), dropping to minima of 1.6 and 2% in autumn, respectively. Finally, maximum of K+ fraction of 3% was observed in spring and autumn. Main sources of PM10 inorganic ions are secondary sulfates and nitrates, soil resuspension, road salt, and biomass burning in spring and autumn
- Добавил в систему: Чичаева Марина Александровна