Characterization And Sources Analysis Of Heavy Metal Aerosols In North Suburb Of Nanjing

Heavy metal aerosols particles were first measured with Single Particle Aerosol Mass Spectrometry (SPAMS) in north suburb of Nanjing from March to April,2012 and 2013. The sample point is located in Nanjing city, on the north side of the east is steel mills, the northeast is a chemical plant.Using the ART-2a neural network algorithm, we studied the chemical characteristics of aerosol particles and found that these aerosols particles can be classified into six kinds according chemical composition:K-rich, DUST, K-EC, Cu-EC, Zn, Mn, which mainly comes from iron and steel making, fugitive dust, fuel drain and chemical emissions, with their respective contributions around 70.66%,24.53%,2.47% and 2.34%.Based on the full year 2013 aerosol particles containing Cu, As, Pb, Cd, Co, Cr, Zn, Ni, V, Ba and Hg discussed the characteristics of the heavy metal aerosol particles aerosol number and peak area has good correlation. Almost all of the heavy metal aerosol particles high value appears in the march, September and October, and relatively low in May and August, different seasons of different kinds of aerosol particles of heavy metals were relatively obvious diurnal variation, but overall peak of various heavy metal containing aerosols are not the same, the source direction is different. The ART-2a neural network algorithm was applied and five main classes of particle were characterized:K-rich, Carbon, Dust, and metal, with sub-classes within each. Combined particles mainly wind direction, diurnal trend; correlation etc, the main sources of heavy metal aerosols in Nanjing was industrial emissions, biomass buring, traffic emissions, fuel combustion and dust, accounting for 35.7%,34.45%,13.6%,11.03% and 4.07% respectively. Then, using peak area to calculate the source contributions of 11 heavy metal types, and the results are as follows:we may predicted that Cu-containing particles mainly contribution to biomass buring(45.91%) and fuel combustion (25.54%); As-containing particles mainly from fuel combustion (54.53%) and biomass buring (45.91%); Pb-containing particles mainly attribute to industrial emissions (96.35%); Cd-containing particles mainly attribute to industrial emissions (60.83%) and biomass buring (26.86%); V-containing particles mainly from traffic emissions (42.71%) and biomass buring (34.72%); Co-containing particles mainly attribute to biomass buring(36.57%) and industrial emissions (30.26%); Cr-containing particles mainly attribute to industrial emissions (54.52%) and biomass buring (22.59%); Zn-containing particles mainly from traffic emissions (45.14%) and industrial emissions (42.99%); Ni-containing particles mainly from fuel combustion(56.77%) and biomass buring (25.66%); Ba-containing particles mainly contribution to traffic emissions (64.54) and industrial emissions (27.3%); Hg-containing particles mainly from biomass buring (86.3%).