Effect of atmospheric dry and wet deposition on heavy metal content in farmland in the Nanjing section of the Yangtze River
To evaluate the effect of atmospheric dry and wet deposition on the farmland soil,accumulations of eight heavy metals in the farmland soil along the Yangtze River of Nanjing have been studied with estimation of dry and wet deposition flux and calculation of heavy metal content and change rate.Results show that the content of heavy metal Cd in the atmospheric dry and wet deposition is sig-nificantly higher than that in the surrounding soil.The average content of Cd in the dry deposition is 0.84 mg/kg,which is 2.8 times the screening value.Average annual deposition fluxes of As,Cd,Cr,Cu,Hg,Ni,Pb and Zn are 12.1,1.60,89.1,47.9,0.092,46.6,36.6 and 116 g/(hm2·a),respectively.Cd is the most significant heavy metal affected by atmospheric dry and wet fallout on soil,showing an increase of 5.33 ng/g after one year of atmospheric dry and wet deposition and an annual change rate of 1.38％,indi-cating that atmospheric deposition is one of the important sources of heavy metal Cd in the farmland soil.
atmospheric dry and wet depositionsoilheavy metalarea along of the Yangtze River,Nanjing
NETL
NSTL
万方数据
