关键词: 重金属, 形态分布, 生物有效性, 矿区, 土壤

Abstract: In order to assess the bioavailability of heavy metals in agricultural soils of Shizhuyuan mining and adjacent area， the sequential extraction procedure method was used to analyses the speciation of heavy metals（Cu， Pb， Zn， Cd， As and Hg）and bioavailability of heavy metals in agricultural soils. The results showed that: ①the soils are not contaminated by Hg， but polluted by Cu， Pb， Zn， Cd and As in different degrees especially by Cd， As. ②Cu， Pb and Zn were dominated by the bound to iron and manganese oxides fractions which accounted for 48.3%， 67.3% and 47.1% of the total content respectively. Cd， Fe， Mn oxides combined state content is the highest， followed by residual fraction， exchangeable fraction， and carbonate fraction. As and Hg were dominated by residual fraction and both accounted for more than 90%. ③Cd had the highest effective contents in mining and its adjacent area， the average proportion was 31.1%， which was much higher than the other 5 heavy metal elements， bioavailability is the highest， effective state of As content is the lowest， bioavailability is the lowest. Finally， suggestions on using stable remediation technology to clean pollution sources， using calcium dihydrogen phosphate to reduce the biological effectiveness of the most seriously polluted elements of Pb and Cd in soil， and using Typha and other plants to remediate abandoned industrial and mineral land and some unused land was put forward.

Key words: Heavy metal, Speciation, Bioavailability, Mining area, Agricultural soil