模拟淹水条件下三峡库区消落带土壤重金属形态变化

Changes of soil heavy metal forms of Three-Gorges Reservoir water-level fluctuation zone under the flooding simulation

采集三峡库区小江流域消落带土样,通过室内模拟试验和化学分析,考察土壤理化性质和消落带土壤淹水前后重金属（Fe、Mn、Cu、Zn）形态变化。结果表明：淹水导致Fe2＋、Mn2＋、有效铜等重金属含量增加,平均含量分别从58.88、35.26、0.96mg/kg增加到1 383.8、782.7、1.73mg/kg;淹水15d后,部分样品有效锌含量增加10.15%~12.18%,部分样品有效锌含量减少3.69%~7.12%;淹水30d后,有效锌的含量增加10.9%~46.6%。土壤基本理化性质对土壤重金属含量也有影响。

Soil samples on Xiaojiang watershed water-level fluctuation zone in the Three Gorges Reservoir Area were collected for the study. By simulation incubation and chemical analysis, the basic physical-chemical properties of soils and the changing forms of heavy metals （Fe2＋ , Mn2＋ , available Cu and Zn） were examined in continuous anoxic conditions. The results showed that flooding increased the contents of the Fe2＋ , Mnz＋ , available Cu. The contents increased on average from 58. 88,35.26,0. 96 mg/kg to 1 383.8,782. 7,1.73 mg/kg,respectively. After 15 days＇ flooding,the contents of available Zn in both Gaoyang and Yanglu increased at the rates of 12. 18% and 10. 15%, but the other forms de- creased at the rates of 7. 12 % and 3. 69 %. After 30 days＇ flooding, the contents of available Zn increased with the increment rate ranging from 10. 9% to 46.6%. The changing form of heavy metals were influ- enced by the basic physical and chemical properties of soils.