摘要论文以钢铁厂的废渣—磷酸渣为修复剂，将其应用于受重金属污染的靶场土壤的修复中。分别在两种土样中加入不同量的修复剂，经过30天的培养，通过一系列化学形态提取实验评价修复效果。采用去离子水提取可溶性重金属，以评价靶场土壤中可溶性重金属的含量。采用DTPA提取Pb和Cu等重金属，采用NaHCO3提取As和Sb，以评价土壤中有效态重金属含量。采用不同pH值的溶液作为提取剂，探究外界条件的改变对靶场土壤中重金属的形态产生的影响。最后，通过BCR（欧洲共同体参考物机构）分级提取实验，探究土壤中重金属形态分布，通过TCLP（Toxicity Characteristic Leaching Procedure，毒性特征浸出过程）确定土壤所含各重金属元素的浓度。实验结果中，TCLP毒性浸出实验所检测出的Pb和Cd的浓度分别为0。001和0。036 mg/L，均远小于美国国家坏境保护局规定的最低限制，表明磷酸渣可以应用于靶场土壤的修复；靶场土壤的pH值在修复前后都在8左右，没有较大的变化，因此磷酸渣的加入不会对靶场土壤的pH产生较大的影响；经过pH稳定性测试，pH值为3的试剂对重金属的钝化效果最好，是磷酸渣修复靶场土壤重金属的最佳施用条件；磷酸渣的加入使靶场土壤中Pb的酸可提取态由48%降为0，而残渣态则由12%升为45%；Cu的酸可提取态由39%降低为0，而残渣态由17%升高到49%，因此Pb和Cu都由不稳定的酸可提取态转化成了更稳定的残渣态；而使靶场土壤中As的酸可提取态略微有所增加，残渣态则由47%降为0，说明As逐渐向不稳定的形态转化，所以磷酸渣对于靶场土壤中的Pb和Cu有很好的固定作用。73652

毕业论文关键词  磷酸渣  靶场土壤  重金属  修复   

毕业设计说明书外文摘要

Title  The application of phosphate residue in the remediation of shooting range soils

Abstract The tested soil samples used in this study are taken from the shooting range soils in Nanjing University of Science and Technology。 We take the phosphate residue of some steel plants as raw materials for our experiments。 Different amounts of restorative composition were added in two different soil samples。 After up to 30 days' cultivation，we can evaluate the effect of the remediation through a series of extraction experiments of chemical forms。 The water-soluble heavy metals will be extracted by deionized water to evaluate the content of soluble heavy metals in soils 。In order to evaluate the available heavy metals，we operate the extraction experiments by DTPA and NaHCO3 。 To explore the changes of external conditions on the content of soil heavy metals in shooting ranges,we take different solution of different pH value for extraction experiments 。We can also explore the distribution of heavy metals in shooting range soils through BCR (European Community Reference Agency) sequential extraction experiments。 By Toxicity Characteristic Leaching Experimental(TCLP), we can evaluate of the content of different kinds of heavy metals in the soils。 Detected by TCLP, the concentration of Pb and Cd is 0。001 and 0。036 mg/L, less than the minimum limit prescribed by the state of the United States Environmental Protection Agency , indicating that the phosphate residue can be used to repair the soils。The pH after remediation is about 8, without a big change, so phosphate residue will not make great influence to the pH of soils。 Through the pH stability test, pH 3 is the best application conditions of phosphate residue when repairing heavy metals in shooting range soils。 Phosphate residue gradually reduce the acid extractable statement of Pb in soil by 48% rto 0, and the residue statement from 12% to 45%。 For Cu, of acid extractable statement decreses from 39% to 0, and the residual statement from 17% to 49%。 Therefore, Pb and Cu transformed  into a more stable statement。 But to As, the residue statement declined by 47% to 0, indicating that the statement was getting more and unstable。 In conclusion, phosphate residue in the shooting range soils has a good fixation effect to Pb and Cu。