The cities in the northeast cold region represented by Harbin have large
emissions of air pollutants, complex emission systems, and special climatic
conditions. They are not only different from traditional key air pollution prevention
and control areas such as Beijing, Tianjin and Hebei, but also from European and
American cities with similar or higher latitudes. Regions are also different.
Therefore, its atmospheric environment is unique in the world. Atmospheric fine
particulate matter (PM2.5) is the concentrated manifestation of regional haze
pollution in my country at this stage. Its chemical composition and environmental
impact are too complex, and it has always been an international frontier and hot
issue in the field of atmospheric environment research. In this study, aiming at the
emission characteristics and climate characteristics of cities in typical cold regions
of Northeast China, long-term continuous field observations of PM2.5 covering the
entire 2019-2020 heating season were carried out in urban Harbin.
Through chemical species analysis, it was found that the concentration of
inorganic aerosols can reach nearly half of PM2.5. The water-soluble inorganic ions
in Harbin heating season mainly include sulfate, nitrate, ammonium salt
(collectively referred to as SNA) and chloride ion, which can achieve an anioncation balance.
The correlation analysis shows that PM2.5 is significantly positively correlated
with SO2 and NO2, indicating that the contribution to PM2.5 includes the
comprehensive contributions of various combustion sources such as coal
combustion and motor vehicles, plus the contribution of secondary formation of
inorganic aerosols generated from gaseous pollutants.
However, the analysis study under heavy pollution weather showed that the
conversion efficiencies of sulfur and nitrogen from gaseous pollutants to particulate
matter, SOR and NOR, were both positively correlated with RH, indicating that
even at low temperature, the heterogeneous reaction would be enhanced under high
humidity conditions. The results of this study show the chemical composition and
variation of PM2.5. |
