MONTHLY VARIATIONS AND CHEMICAL COMPOSITIONS OF PM1 AND PM2.5 DURING THE HEATING PERIOD IN HARBIN, CHINA.

In order to investigate monthly variations and chemical compositions of atmospheric particulates during the heating period, PMi and PM_2.5particulates were sampled and analyzed, including the characteristics of size distributions and mass concentrations of metal elements and ions. In addition, the sources of metal elements in PM₁ were analyzed by the Enrichment Factor (EF). The results showed that the mass concentrations of As, Ba, Cr, Cu, Zn, Mn, Ni, Pb, Sr, and Ti ranged from 0.018 to 0.8 μg/m³, while Ni was not detected in December. The mass concentrations of AI, Ca, Fe, K, Mg, and Na ranged from 0.4 to 12.5 μg/m³, in which the concentrations of Na and Ca were much liiglici-willi the values of 9.091 and 12.131 μg/m³, respectively. The characteristics of size distributions showed that the metal elements accounted for 56%~97% of the total mass of PMi, which indicated that the metal elements were mainly enriched in ultrafine particles. The variations of ions in PM₁ and PM_2.5 were the same. The total mass concentrations of 9 ions in PM₁ and PM₁.swere from 30.5 μg/m³to 60.9 μg/m³ and from 38.7 μg/m³to 78.0 μg/m³ respectively during the heating period. The mass concentrations of SO42" and NO₃^- were higher than other ions, and that of Mg²⁺ and I were lower between 0.1 μg/m³ and 0.95 μg/m³. Enrichment factor analysis suggested that the EF values of the metal elements except Mn and F^- were more than 10, and they were primarily emitted from anthropogenic sources including coal combustion, burning straw, automobile exhaust and fireworks. The EF values of As, Pb were about 1000 which were mainly from fossil fuel combustion. It also showed that the combustion of coal and other fossil fuels during the heating period was the main reason for the increase of some heavy metal elements. [ABSTRACT FROM AUTHOR]