GEOCHEMISTRY AND EVALUATION OF ATMOSPHERIC DRY AND WET DEPOSITION IN JINGDE-NINGGUO AREA, ANHUI PROVINCE

Taking the atmospheric dry and wet deposition in Jingde-Ningguo area of Anhui Province as study object, a total of 24 samples are collected from 6 sites to comparatively analyzes the element content and flux characteristics of atmospheric dry and wet deposition, statistically study the element content and distribution features of dry and wet deposition, and carry out the environmental geochemical evaluation as well. The results show that atmospheric dry and wet deposition elements mainly exist in the form of mineral facies or adsorbed on solid particles, and they are affected by surrounding environment. The high Cd and Se contents in dry deposition have great impact on soil pollution in the study area, the pH values of some wet deposition sampling sites exceed the irrigation water quality criteria, and all sites reach the Grade Ⅱ surface water environmental quality standard. As to the annual deposition flux density of heavy metal elements, the deposition flux of As is low, Hg, Ni, Pb, Cr, Cu and Cd lower, and Zn higher. The flux of heavy metal elements in dry and wet atmospheric deposition is generally smaller in hilly areas than in towns and industrial/mining areas, mainly affected by coal combustion, exhaust gas emission and human activities. The evaluation results of environmental geochemistry single index and comprehensive index for atmospheric dry and wet deposition are both Grade Ⅰ.