Study on the Characteristics of Heavy Metal Contents and Annual Fluxes of Atmospheric Dry and Wet Deposition in Jinan City Using AFS and ICP-MS

Atmospheric deposition is an important source of heavy metals in surface soil, the study on the geochemical characteristics and source analysis of heavy metals in atmospheric dust would provide important guidance for pollution prevention. The contents of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in atmospheric dust in Jinan have been analyzed by Atomic Fluorescence Spectrometry (AFS), Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and X-ray Fluorescence Spectrometry (XRF). The correction analysis and principal components analysis (PCA) were used to source the heavy metals. The average contents of Cd, Cr, Cu, Hg, Pb and Zn in atmospheric dry and wet deposition are 2.07 mg/kg, 135.9 mg/kg, 65.7 mg/kg, 218.6 μg/kg, 110.7 mg/kg, 380 mg/kg, respectively, which are higher than the background values of these elements in soil and has an obvious enrichment due to the contamination by human activities. Cd, Cu, Hg, Pb are mainly derived from coal combustion, As and Cr are derived from road dust, Ni may be derived from soil dust, and Zn is derived from traffic discharges. The coal combustion and road dust are the main pollution sources of atmospheric deposition in Jinan, with the contribution proportion of atmospheric deposition up to 50.13%. Atmospheric dry and wet deposition produce significant effect on the contents of Cd, Hg, Cr, Pb, Zn and As in urban topsoil, the annual deposition flux of Zn is the highest with a mean of 148 mg/(m²·a), whereas the annual deposition flux of Hg is the lowest with a mean of 0.085 mg/(m²·a). Moreover, Cd and Hg contents have higher growth rates, and dry and wet atmospheric deposition significantly influences the As and Cr accumulation in soils.