Abstract:

A series of investigations were performed to show the current situation of  pH of precipitation and wet deposition of heavy metal, in Changchun City, China. A total of 12 samples of atmospheric precipitation were collected at three representative sites using bulk deposition sampling method in the periods of 2006-2007(about one year). The heavy metal content were analyzed by atomic fluorescence spectrometry (AFS) and Inductively Coupled Plasma-Mass Spectrometric (ICP-MS). According to the analytical results, the average pH value of the precipitation was 6.43, which was neutral as a whole. The content of Hg, Cr, Cu, Zn, As, Pb and Cd in precipitation in Changchun is generally low with the concentrations of 0.042,3.59,9.25,148.6,18.44,21.71,0.933μg/L respectively. The concentrations of heavy metals were generally higher in the spring and winter period than that in the summer and autumn period,which might be the result of washouting effect in rainy season, meanwhile, the concentrations of heavy metals were generally lower in the area of automobile factory than in the other areas. According to the calculated results, the wet deposition fluxes of As,Cd,Cr,Cu,Hg,Pb and Zn in Changchun were 2.13,0.21,1.70,3.74,0.019,6.82,65.78 mg/(m²·a), respectively. The deposition fluxes of heavy metals were generally higher in the March to September periods than that in the other periods.

Key words: atmospheric precipitation, pH, heavy metals, deposition flux, Changchun City