混合浸提剂对土壤中Cd和Cu浸提效果的研究

Study on the effect of mixed extractant on Cd and Cu in soil

为研究碱性混合浸提剂Na_(2)EDTA和柠檬酸钠对不同土壤中Cd和Cu的浸提效果,对混合浸提剂浓度、固液比和pH进行单因素实验,同时采用响应曲面法分析最佳浸提条件,对土壤采用BCR连续浸提法研究浸提前后金属的赋存形态变化。结果表明,碱性浸提剂对弱酸性土壤中的金属Cd和Cu具有较好的浸提效果;混合浸提剂比单一浸提剂的效果更好;不同土壤因为其金属赋存形态的不同,其最佳浸提条件存在一定差异,浸提后Cd和Cu元素以有机结合态为主要形式存在。此混合浸提剂能有效提取土壤重金属,为酸性土壤的金属提取和检测提供了思路。

In order to study the effects of Na_(2)EDTA and sodium citrate and the effects of their mixed on the extraction of Cd and Cu in different soils.Single factor experiments were carried out on the concentration of mixed extractant,solid-liquid ratio and the pH.At the same time,response surface methodology was used to analyze the optimal extraction conditions.BCR continuous extraction method was used to study the changes of metal speciation before and after extraction.The results show that the mixed extractant has a good leaching ratio on Cd and Cu in weak acid soil.The effect of mixed extractant is better than that of single extractant.The optimum extraction conditions is different in different soils because of the different forms of metal morphology,and the extracted elements is mainly in the form of organic bound state.The mixed extractant can effectively extract heavy metals from soil,which provides ideas for metal extraction and detection in acid soil.