Студенттер мен жас ғалымдардың «фараби әлемі» атты халықаралық ғылыми конференциясы
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Сборник конф Фараби Әлемі 2023 химфак-печать
| CHEMICAL COMPOSITION OF PM
2.5 IN AMBIENT AIR IN ALMATY, KAZAKHSTAN Tursun K., Ibragimova O.P., Bukenov B., Mukhtarov R., Tursumbayeva M., Omarova A., Kashtanov A. Supervisor: PhD., associate professor Baimatova N. Center of Physical Chemical Methods of Research and Analysis, Al-Farabi Kazakh National University Air pollution in Almaty strengthens public concern from day to day. In 2018, the PM 2.5 concentration in Almaty (53 µg/m 3 ) exceeded the WHO limit by 5.3 times [1]. There is a plethora of research aimed at developing methods for the quantification of various pollutants, identifying spatiotemporal variations in pollutant concentrations, and assessing health risks. Existing studies only proposed possible pollution sources, however there is no scientific evidence of which PM 2.5 source is dominant in the city. This study shows levels of elements, including heavy metals, ions, and organic and elemental carbon (OC/EC) in PM 2.5 , collected from May 30 to September 30, 2022. Daily OC concentrations ranged from 3.9 to 13.8 µg/m 3 with an average value of 6.2 µg/m 3 in Almaty. Daily EC concentrations were significantly lower than OC concentrations: from 0.6 to 2.5 µg/m 3 with an average value of 1.1 µg/m 3 . The OC and EC concentrations were weakly correlated (r=0.43), indicating the absence of a single dominant source of OC and EC in Almaty. Ion concentrations in PM 2.5 decreased in the series SO 4 2− >NH 4 + >NO 3 − >Na + >Cl − >K + with concentrations of 1.07, 0.61, 0.28, 0.26, 0.25, 0.12 µg/m 3 , respectively. The total mass concentration of ions was 3.0 µg/m 3 . The sulfate ions made the largest contribution to the total mass concentration of ions (41%), which can be caused by coal combustion. The NO 3 − /SO 4 2− ratio was below 1 in all samples except for June 6 and 14, indicating the effect of coal combustion during the sampling period. The main elements in the composition of PM 2.5 were Na, Mg, Al, K, Ca, Cr, Fe and Ni, the daily concentrations of which varied from 11 to 4071 ng/m 3 . The average monthly concentrations in July and August were characterized by the lowest concentrations of most elements. High concentrations of Al in PM 2.5 may indicate pollution from coal combustion, while high levels of K indicate pollution from biomass combustion. The chemical composition of PM 2.5 and receptor modeling can be further used to investigate the contribution of various sources of pollution to the concentration of fine PM 2.5 жүктеу/скачать 2,6 Mb. Достарыңызбен бөлісу:
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