A Study Of The Source Apportionmentof PM₁₀、PM_2.5 In Guiyang

Guiyang is the largest industrial base of Guizhou province, coal as the main industrial and life energy is used by a lot of. It locates at the intermountain basin, with typical karst landform characteristics. Because of the breeze and the static windy climate condition, the pollutants in the air are very unfavorable to be diluted and diffused. This study selected 2 representative sampling sites in Guiyang, and took the inhalable particles in atmosphere(PM10)、atmosphere fine particles(PM2.5) and 3 kinds of chemical components as subjects, including Carbon component, Water-solubility component and Inorganic component, took sample from spring to winter, finally it discussed the seasonal variation characteristics of PM10、PM2.5 and its concentration level in depth. Besides, the concentration level, seasonal change, distribution of spatial of Carbon component, water-solubility component and Inorganic component in PM10 and PM2.5. In order to establish the PM10、PM2.5 source profiles of Guiyang, the representative sources of pollution in Guiyang were identified, that are soil dust,urban fugitive dust, construction and cement dust, steel dust, coal dust, automobile tail gas dust, secondary sulfate and secondary nitrates. Then all samples of souces were sampled based on identifing and apportioning the sources of PM10 and PM2.5. Finally Carbon component, water-solubility component and inorganic component in those samples were analyzed. The chemical mass balance model(CMB) was used for the source apportionmeng of PM10 and PM2.5 in Guiyang city. The main conclusion is as follow:1、The mean concentration of PM10、PM2.5 is 115.17μg/m3 and 75.21μg/m3 in Guiyang, respectively. The obvious seasonal variation characteristics was appeared: winter>autumn>spring>summer due to the increasing of coal combustion in winter, the temperature inversion weather occurred frequently and the small wind speed, the spread of pollutants becomes difficult, which causes high concentrations of the atmospheric particulate; While in summer, due to the strong solar radiation, air convection activities, the shorter time of generating and existing thermal inversion layer and raining, the concentrations of atmospheric particles is relatively low.2、The inorganic elements are divided to earth elements and pollution related elements. As the result of analyses, the concentration of Si is the most highest in earth elements of PM10 and PM2.5, the mean concentration is 7.62μg/m3 and 5.73μg/m3 respectively and the concentration of Zn, Cu, Cr and Pb are higher in pollution related elements. Generally speaking, the obvious seasonal variation characteristics of pollution related elements was appeared:winter > spring > autumn > summer. In spatial distribution, the concentration of Cr, As, Cd, Ni and V are higher in Baiyun, while the concentration of Cu, Zn and Pb are higher in Baoshan.3、During the sampling the concentration of OC and EC is 17.90μg/m3 and 5.70μg/m3 in PM10, and 14.83μg/m3 and 4.95μg/m3 in PM2.5, respectively. The obvious seasonal variation characteristics was appeared:winter>autumn>spring>summer. In the district of Baiyun has the higher value of OC and EC with their mass fraction in PM10 and PM2.5. Moreover, all the OC/EC ratios in PM10 and PM2.5 of four seasons exceeded 2.0, which suggested that there existed secondary organic carbon in ambient air in four seasons, and the secondary organic carbon serious pollution is autumn.4、The concentration of SO42- is highest in the cation, its mass fraction in PM10 and PM2.5 is 17.51% and 24.99, respectively. The obvious seasonal variation characteristics of NO3- and SO42- was appeared:winter>autumn>spring>summer, and in the district of Baiyun has the higher value of 3 kinds of water- solubility. At the same time, all the [NO3-]/[SO42-] ratios in PM10 and PM2.5 of four seasons is small, which suggested that the main source of ambient air in Guiyang is stationary source, which is from coal smoke dust.5、Marker element appear to dominate each source profile. Marker element of soil dust is Si, marker element of construction and cement dust is Ca, marker element of steel dust is Fe, marker element of automobile tail gas dust is OC, marker element of coal dust are EC and Se, respectively. Meanwhile, it is proved that urban fugitive dust belongs to mixed sources. So it does not have marker element. For example, urban fugitive dust is mainly affected by soil dust and construction and cement dust.6、The mostly source of PM10 in Guiyang city is secondary sulfate, automobile tail gas dust, coal dust, urban fugitive dust and secondary nitrates, and the contribution is respectively 26.76%, 19.99%, 19.78%, 4.02% and 3.55%, and the part of incertitude is 25.70%. The mostly source of PM2.5 in Guiyang city is secondary sulfate, automobile tail gas dust, coal dust, secondary nitrates and urban fugitive dust, and the contribution is respectively, and the part of incertitude is 31.44%, 21.05%, 18.25%, 6.16% and 3.61%, and the part of incertitude is 19.39%. At the same time, distinct seasonality was observed for the sources of soil dust, urban fugitive dust, secondary sulfate, coal dust and secondary nitrates.