工业园区农用土壤中重金属Cu和Pb的形态研究

Research on Speciation of Heavy Metals(Cu,Pb) in Agricultural Soil from Industrial Parks

以大冶市一工业园区农用土壤为研究对象,采用BCR连续提取法提取并测定了样品中重金属Cu和Pb的形态和含量,分析了重金属各形态、土壤pH和有机质之间的相关性;同时,对重金属的分布特征和有效性进行了分析,探究土壤本身性质对工业园区农用土壤重金属及其生物有效性的影响。结果表明:工业园区农用土壤受重金属的污染程度大小为:Cu>Pb且Cu含量与土壤有机质含量之间呈显著正相关,Pb含量与Cu_(有效态)含量之间有显著相关性,表明工业园区农用土壤中重金属Pb与Cu_(有效态)之间相互促进和相互影响的作用较强。工业园区农用土壤pH值与Pb_(弱酸提取态)含量、Cu_(可还原态)含量之间相关性显著;有机质的含量与Cu_(可氧化态)含量、Cu_(可还原态)含量之间相关性显著,可见土壤pH和有机质含量均会对重金属Cu和Pb在土壤中的存在形态有较大影响。

Soil samples in agricultural soil of an industrial park in Daye were collected. The soil samples were treated with BCR procedure. The correlations between the contents of heavy metals,soil pH value and properties were analyzed. The distribution character and the bioavailability of heavy metals（ Cu,Pb） were discussed. The purpose of the procedure was to find the impact factors. The results indicated that the soil had been polluted in different degrees by heavy metals in the industrial park. The pollution degree of heavy metals in the order was Cu Pb; the total contents of Cu exhibited significantly positive correlation with soil organic matter. Existing as available fraction,the contents of Cu exhibited significantly positive correlation with Pb. The role of mutual promotion and mutual influence were stronger between Pb availability and Cu availability in the agricultural soil of the industrial park. The contents of Pb existing as weak acid soluble fraction,Cu existing as reducible fraction,exhibited significantly positive correlation with pH; the contents of Cu existing as reducible fraction and oxide fraction,exhibited significantly positive correlation with organic matter,which indicated that soil pH and organic matter had a certain impact on chemical speciation of heavy metals.