Analysis On The Chemical Composition Of PM_2.5 And The Effect Of Biomass Burning Combustion In Northern Surburb Of Nanjing

As a major pollutant in the atmosphere,PM is the main cause of haze formation in most cities in China,and it is also a serious threat to human health.Carbon in carbonaceous aerosols mainly consists of two major categories,organic carbon and element carbon,which have different source characteristics.As an important part of the Yangtze River Delta region,Nanjing has become more and more serious in recent years.The carbonaceous aerosol,especially the two organic carbon,is an important part of fine particles in haze weather.Therefore,exploring the pollution characteristics and transportation sources of carbonaceous aerosols in this area will help better serve for pollutant control in Nanjing and the Yangtze River Delta.The characteristics of the 2015-2016 annual four season months monitoring OC,and EC data of four seasons of the pollutant concentration level,seasonal characteristics were analyzed and the correlation between OC and EC was explored and the second organic carbon(SOC)of accounting and through the backward trajectory the model of the air pollution are analyzed,ten kinds of PM2.5 water soluble ion acidity,seasonal variation,correlation and study of PM2.5 in three kinds of dehydrated sugar concentrations,seasonal variation,and levoglucosan carbon fractions and the correlation between the biomass burning in Nanjing industrial zone effect analysis,conclusions are as follows:(1)The average annual mass concentration of OC is 12.7 ?g·m-3.The average annual mass concentration of EC is 1.6 ?g·m-3.The annual average OC/EC value is 8.8.It shows that the monitoring site is greatly influenced by the emission of fossil fuel combustion.The correlation of OC to EC in spring,smmer and autumn is relatively good,in spring,summer,and summer during this paper monitoring.In autumn,OC and EC have similar origins.The correlation between OC and EC is relatively poor in winter.The source of carbonaceous aerosols is more complex,may be affected by a emission source,may be affected by regional polluted air mass,and may also be affected by the photochemical reaction of organic gases.(2)Spring and summer are mainly affected by the local area of China north and northwest pollutants heavy industry developed area gas head distance transmission and the northeast of Jiangsu air pollutants short distance input,pollution situation in Nanjing area is relatively heavy;autumn due to purification into eastern ocean climate and clean air,pollution in Nanjing region is relatively good;in winter due to the impact of air mass transport short distance local area in the eastern coastal region,North Industrial Zone of Jiangsu and from Jiangxi,Henan,Anhui,the way of influence air pollution,relatively heavy and complex sources.(3)Nanjing PM2.5 overall acidic acid for each season:spring>summer>autumn>winter;the average concentration of water soluble ions in the annual monitoring period is 52.10 ?g·m-3,the average concentration of spring water soluble ions of 57.16 ?g·m-3,the average concentration of water soluble ions in summer the 46.25 ?g·m-3,the average concentration of water soluble ions in the autumn of 42.75 ?g·m-3,the average concentration of winter water soluble ions of 90 ?g m-3,the average concentration of water soluble ions in order:winter summer>autumn>spring>;water soluble inorganic PM2.5 the ion is mainly,the three annual average concentration of ions is as follows:19.04 ?g·m-3,16.88 ?g·m-3,12.11?g·m-3,accounted for 91.73%of all the ion,and the PM2.5 The source mainly comes from the burning of coal and the exhaust of motor vehicles in the production process of industrial enterprises.(4)Nanjing PM2.5 three dehydration sugar with the content of levoglucosan most,the annual average concentration of dextrose,mannan and galactosan were 209.6 ?g·m-3,19.3?g·m-3,5.7 ?g·m-3;levoglucosan concentrations in a seasonal order:Autumn>spring>winter,major it is because of the fall there was a biomass burning pollution;good autumn levoglucosan and SOC and the correlation between OC and SOC,levoglucosan and OC with homology;mainly from the Northeast Nanjing direction autumn biomass burning pollution,via Hebei,Shandong,finally arrived in Nanjing,autumn biomass burning contribution the estimation results of OC 21.7%,heavy pollution from October 13 th to October 16th with the estimation results of the combustion of biomass was 30.1%OC,the exogenous The biological combustion of biomass has a great influence on the pollution in Nanjing in autumn.