Pollution Characteristics and Sources of Carbon Components and Water-Soluble Ions in Atmospheric Particulate Matter in Nanjing, China - Abstract
In order to study the component characteristics and sources of PM2.5 in the northern suburbs of Nanjing, 191 PM2.5 samples were collected and quantitatively analyzed for watersoluble ions (WSI), organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC). The annual average mass concentrations of OC, EC, and WSOC were 5.30 ?g m-3, 0.96 ?g m-3, and 3.09 ?g m-3, respectively. The variation characteristics of their seasonal abundance were basically the same, which reached the maximum in winter and the lowest in summer. Based on the ratio of organic carbon to elemental carbon, we find that the air in the northern suburbs of Nanjing is affected by coal burning, exhaust emissions and biomass combustion. The annual mean mass concentration of WSI in PM2.5 was 23.00 ?g m-3, and the order of seasonal concentration was winter > autumn > spring > summer. The WSI in PM2.5 are mainly SO4 2-, NO3 -, and NH4 +. Through the concentration ratio of NO3 -/SO4 2-, we found that mobile sources were the main sources of pollution in autumn and winter, while stationary sources were the main sources of pollution in summer. Through the iterative calculation of PMF, five sources of PM2.5 are determined, which are second generation (37.5%), traffic-related source (36.7%), combustion source (9.6%), marine source (8.5%), and industrial emissions (7.7%). In different seasons, PM2.5 is significantly correlated with SO4 2-, NO3 -, and NH4 +, indicating that PM2.5 mainly comes from secondary generation.