某电镀厂附近农田土壤中的重金属形态研究

通过连续提取法对电镀废水污染区和对照区农田土壤中的重金属元素Cu、Cr、Ni、Pb和Mn形态进行了研究.结果显示,污染区土壤中多种形态的Cu、Cr和Ni含量都显著高于对照区,尤其以它们的有机结合态差异最为显著.污染区较对照区土壤中Mn的总量虽无显著差异,但可交换态Mn的含量显著增加(分别为98.68mg/kg和40.75mg/kg).污染区与对照区土壤中的Pb的交换态、碳酸盐结合态、Fe-Mn氧化物结合态、有机结合态和残留态均无显著差异.电镀废水的污染使得农田土壤中Cu、Cr和Ni含量和生物有效性显著升高,Mn的化学形态改变,移动性和生物有效性增加.

Fractionation of Heavy Metals in Cropland Soil Near an Electroplating Plant

The fractionation of Cu,Cr,Ni,Pb and Mn in the contaminated and non-contaminated cropland soils near an electroplating plant was researched using the five-stage sequential extraction procedure.The results indicated that the various fractions of Cu,Cr and Ni in the contaminated soil,especially for the organic matter fraction,were significantly higher than those in the non-contaminated soil.There was no significant difference in the total concentration of Mn between the contaminated and non-contaminated soils.However,the exchangeable concentration of Mn in the contaminated soil(98.68mg/kg) was significantly higher than that in the non-contaminated soil(40.75mg/kg).Moreover,no significant differences existed between the contaminated and the non-contaminated soils for the Pb concentrations in the exchangeable fraction,the carbonate fraction and the iron-manganese oxides.The concentration and the bioavailability of Cu,Cr and Ni increased significantly in the contaminated soil.Mobility and biotoxity of Mn in the contaminated soil were increased due to the transformation of Mn fractions.