添加物对土壤提取液中铜、镉生物毒性的影响

本文着重讨论添加物紫云英、CaCO₃、膨润土对土壤提取液中Cu、Cd的降毒效应及其金属形态的影响.测试结果表明,添加CaCO₃对降低红壤水溶态Cu、Cd和0.1mol/LHCl可提取态Cu、Cd含量及其毒性具有非凡的功能,并能使红壤中可溶态、交换态Cu、Cd明显向有机态、铁锰氧化物包被态和硫化物Cu、Cd转化.换言之,CaCO₃能使红壤中有效态金属向迟效态和无效态金属转化,致使其水、酸浸提液中Cu、Cd毒性被消除.

EFFECTS OF ADDITIVES ON THE BIOLOGICAL TOXICITIES OF COPPER AND CADMIUM IN SOIL EXTRACTS

The effect of additives including milk vetch,CaCO₃ and bentonite on the toxicities of copper and cadmium in soil extracts and their forms were emphatically discussed in the present paper.The ezperimental results demonstrated that of the three additives,CaCO₃ howed an extraordinary ability to lower the contents of water-soluble Cu and Cd and extractable Cu and Cd with 0.1 mol/L HCl eatractant as well as their toxicities in red soil,and it could make the 6sad Cd in red soil transform obviously from water-soluble and exchangeable forms into organit,Fe and Mn oxides occluded and sulphide forms.In other words,CaCO₃ could chapge the available forms of metals into slowly available and unavailable forms,resulting in the elimination of the toxicities of Cu and Cd in water and acid extraction solutions.