Source Apportionment Of Particulate Matter In Baotou

Particulate matter（PM）has become a highly concerned problem in recent years,because of the haze has frequently appeared.The complex of air pollution,combined with huge concentration of PM and unclear sources,which makes it a serious challenge to achieve continuous and effecitive improvent of PM.Therefore,in order to provide support for target prevention and control of PM,research on PM source analysis and quatitatively estimate the contribution of different pollution sources were carried out in no time.PM_2.5,PM₁₀ in different seaons were collected,urban dust,soil dust,building cement dust,coal dust and steel dust were also collected and resuspension as the source samples in Baotou in 2014,which represent a typical industrial city in northern China.The concentrations of heavy metals,water-soluble ions,organic carbon（OC）,element carbon（EC）,silicon（Si）and other components in different samples were analysed.Local industry and pollutant data combined with chemical mass balance receptor model（CMB-iteration）were used to comprehensively explain the source of PM_2.5,PM_10.The main findings were:The concentrations of PM₁₀,PM_2.5,SO₂,NO₂,CO were higher in heating season while O₃ showed an opposite trend.According to the analysis of pollution source composition,the main components of urban dust,building dust,coal dust,steel dust were Si,Al,Ca,OC,and SO₄^2-;Ca,Al and Si;Si,Al,Ca,Fe,EC,OC,SO₄^2-;Si、Al、Ca、Fe、EC、OC、SO₄^2-;Ca,Fe and Zn;OC and EC,respectively.Receptor composition analysis showed that carbon components were highest in PM_2.5,PM₁₀,accounting for 18.5%and 22.3 respectively.Si,Ca,Al were higher in PM2.5 which indicated dust has a stronger impact on PM₁₀.Meanwhile,the higher concentration of SO₄^2-and NO₃^-in PM_2.5 reveals that secondary inorganic ions are important components of PM_2.5.The seasonal source anaylsis results of PM_2.5,and PM₁₀ indicated that open sources were characterized by spring>summer>autumn>winter,which was related to wind speed and construction activities in different seasons,the coal dust was characterized by autumn and winter>spring and summer,and is related to coal-fired heating in winter;the secondary source（secondary nitrate,secondary sulfate）has the characteristics of summer>spring and winter>winter,which is related to the photochemical reaction in summer;The seasonal characteristics of the exhaust dust of cars were not obvious.The results of annual source analysis of PM₁₀ and PM_2.5 showed that the main contribution of PM₁₀ were dust and coal dust,meanwhile PM_2.5 accounted for coal dust,dust,vehicle exhaust dust and secondary sulfate.The comprehensive source analysis showed that dust accounts for most of PM₁₀,followed by industrial production,again vehicle and coal combustion.For PM_2.5,industrial production contributed the most,followed by dust,again vehicles and coal combustion.It can be seen that the pollution sources of PM in Baotou City are mainly due to primary pollution sources such as dust and coal-burning dust generated in industrial production.