Analysis Of Pollution Characteristics And Sources Of Carbonaceous Species In Atmospheric Particulate Matters In Shijiazhuang

Organic Matter?OM?is the main components of fine particulate matter,many have carcinogenic,teratogenic and mutagenic effect.Organic Carbon?OC?and Element Carbon?EC?is the main form of OM in particulate matter,Polycyclic Aromatic Hydrocarbons?PAHs?is the typical organic matter of“three”effects significantly and damage to human health and atmospheric environment.PM₁₀,PM_2.5.5 and PM₁ were collected from June 2017 to May 2018 in the urban and suburban areas of Shijiazhuang.The organic carbon?OC?and elemental carbon?EC?components were determined by Sunset OCEC Model 4L in the United States.The concentrations and temporal and spatial variations of PM₁₀,PM_2.5and PM₁in Shijiazhuang were analyzed.The sources of atmospheric particulate pollution in Shijiazhuang were analyzed by calculating the correlation between Carbonaceous Species and gaseous pollutants,principal component analysis and PMF source analysis.The results show that the average concentrations of PM₁₀,PM_2.5.5 and PM₁ from June 2017 to May 2018 are significantly lower than those from November 2016 to May 2017 by 12.04%,13.44%and40.62%,respectively.When the relative humidity is greater than 50,with the increase of relative humidity,the moisture absorption and concentration of the strong aerosol particles increase with the increase of relative humidity.The results of comparative analysis of eight Carbonaceous Species show that the main pollution sources of PM₁₀0 in winter are coal burning,spring,summer and autumn as vehicle emissions.Road dust contributed significantly to PM_2.5.5 pollution in spring and autumn.OC,EC and NO₂ have strong correlation in spring,indicating that the traffic source has a certain influence on the concentration of carbon aerosol.The correlation between OC and SO₂ is obvious in summer,indicating that industrial coal combustion is one of the sources of carbon aerosol in summer.There is a positive correlation between O₃ and carbon component,and the secondary transformation of pollutants in summer also has a certain influence on the concentration of carbon aerosol.However,the heavy rain in summer and high wind speed accelerate the dilution of pollutants,so that the net production of secondary conversion is lower,and the influence of secondary conversion source on carbon aerosol is limited.The correlation between OC and SO₂,NO₂ was obvious in autumn,indicating that motor vehicle emissions and coal-burning emissions contributed significantly to the carbon aerosols in autumn,and that SOC,SO₂,NO₂ and O₃ also had significant correlation with each other,which indicated that the contribution of secondary conversion sources was significant in autumn.Except for O₃ in winter,there is a significant correlation between carbon component and SO₂,NO₂,which indicates that there is a common contribution of motor vehicle emissions,coal combustion and secondary conversion sources in winter.In autumn,winter,spring and summer,the percent of carbon in PM₁ was the highest,which was 52.5%43.6%and 28.448%,respectively.In autumn,winter and spring,the carbon fraction of gasoline vehicle and diesel vehicle mixed source,coal-fired source and dust source were the highest,which were 42.3%and 41.3%in PM_2.5,respectively,and the highest fraction of carbon component in 44.7%.PM_2.5.5 in summer was the same as that in winter,and it was coal-fired source,accounting for 25.4%.