Characteristics and Source Apportionment of Water-soluble Inorganic Ions in Road Dust PM2.5 in Selected Cities in Liaoning Province

Abstract

In order to collect comprehensive information on the characteristics and sources of water-soluble inorganic ions in road dust (RD) PM2.5 in Liaoning Province, samples of road dust were collected in 2014 and 2016 in Anshan and Panjin and then re-suspended on filters using an NK-ZXF sampler. The concentrations of the major water-soluble inorganic ions were analyzed by ion chromatography. A correlation analysis, ratios, and a principal component analysis were used to analyze the sources of RD. The results showed that the total water-soluble inorganic ions in Panjin and Anshan accounted for 5.83%±3.34% and 5.84%±1.15% in RD PM2.5, respectively. NH4+, SO42-, and NO3- in RD PM2.5 coexisted in the forms of (NH4)2SO4, and NH4NO3 in Panjin, and NH4HSO4 and NH4NO3 in Anshan. The average values of NO3-/SO42- were 0.52±0.55 and 0.46±0.13 for Panjin and Anshan, respectively, indicating that the effects of stationary sources (e.g., coal combustion) on PM2.5 were more significant. The main sources of RD PM2.5 in Panjin were biomass burning, sea salt particles, construction dust, and mobile sources, while the main sources of RD PM2.5 in Anshan were coal combustion, biomass burning, sea salt particles, and steel smelting dust.