The Pollution Characteristics And Chemical Compostion Analysis Of Atmospheric Particulate In A Northen Urban

The pollution characteristics of atmospheric particulate in northen were differentfrom countrywide other city especially in the south, by the special geographical positionof a northen urban. We mainly dicussed the pollution characteristics of TSP, PM10andPM_2.5for sampling airborne particulate matter, to determine the major air pollutants,focusing on the pollution characteristics of ions, metal and organic polycyclic aromatichydrocarbons （PAHs） for the primary air pollutants. We determined the main pollutionsource of atmospheric particles and its contribution ratio in a northen urban according tothe ratio method and the main factor analysis method, for effective control ofatmospheric particle pollution, protect human health to provide a scientific basis.We sampled the samples of TSP, PM10and PM_2.5in a nurthen urban consecutiveone year in2009. The type of air pollutants was TH150made by Wuhan rainbow, andequipped the type of TSP-100、PM10-100、PM_2.5-100inhalable particle cutter samplinghea （diameter was88mm）. We analysed the mass concentrations in the TSP, PM10andPM_2.5for each sample, through the correlation analysis in TSP, PM10and PM_2.5identifed PM_2.5was the primary air pollutants in the northen urban, and considered thepollution characteristics of water soluble ion, metal inorganic elements and polycyclicaromatic hydrocarbons （PAHs） in PM_2.5. The results showed: the annually average TSP,PM10and PM_2.5concentrations respectively:288.76μg/m³,214.81μg/m³and144.89μg/m³, the changes of time was the heating period＞non heating period, theseasonal variation trend for winter＞autumn＞spring＞summer.By using Inductively Coupled Plasma Atomic Emission Spectrometer （ICP-AES）,the Ion Chromatograph （IC） and Nash’s reagent spectrophotometric respectively todetermine anionic, cationic and NH4+in PM_2.5. We revealed that the order of watersoluble anion concentration was SO₄^2-＞NO₃^-＞Cl-＞F-＞NH4+, of metal concentrationwas Ca²⁺＞K⁺＞Na⁺＞Mg²⁺, SO₄^2-、NO₃^-and NH4+wre the main components of watersoluble ions in PM_2.5. The concentrations of SO₄^2-、NO₃^-and NH4+accounted for70%ofthe total ion concentration. We chosen ICP-AES to analyse the metal elements in PM_2.5,the results showed that the order of metal elements concentrations were:Ca＞S＞Na＞Si＞K＞Fe＞Mg＞Zn＞Al＞Ti＞Pb＞Cu＞Ba＞Mn＞Cr＞As＞Ni＞Cd＞Sr＞V.The analysis process of PAHs in PM_2.5was Soxhlet extraction→rotaryevaporation→silica gel elution→rotary evaporation→nitrogen→bottling anddetermined by GC/MS. We known that the annually average of ΣPAHs in PM_2.5was78.61ng/m³, the seasons distribution characteristics for winter（213.57ng/m³ï¼‰ï¼žspring（43.56ng/m³ï¼‰ï¼žautumn（40.42ng/m³ï¼‰ï¼žsummer（40.42ng/m³ï¼‰, annual average PAHs concentration distribution for4rings＞5rings＞6rings＞3rings＞2rings. ThePAHs with4rings occupied44.80%in ΣPAHs, with5rings occupied26.71%in ΣPAHs,with6rings occupied16.10%in ΣPAHs, with3rings occupied10.34%in ΣPAHs, thelowest was with2rings just occupied0.23%in ΣPAHs. Through the ratio and the factoranalysis method, we confirmed that coal and automobile exhaust were the mainpollution sources in City A, the pollution type in City A was compound pollution withcoal and automobile exhaust.