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摘要采用钢铁厂废物磷酸渣作为土壤重金属铅的固化剂，研究了土壤中投加磷酸渣后铅形态的变化，探讨了磷酸渣不同投加量对土壤中铅毒性浸出的影响，通过测定土壤基本理化性质，如pH、电导率、阳离子交换量等，评价了磷酸渣对土壤中铅的固定化效果。实验结果表明，投加磷酸渣后土壤中铅形态发生了变化，可交换态、碳酸盐结合态、氧化态及有机结合态铅含量随着磷酸渣投加量的增加逐渐减少，残渣态铅含量增加，说明磷酸渣投加后铅向更稳定的形态转化；投加量>5% 铅毒性浸出浓度达到EPA规定值，说明施加磷酸渣可降低铅浸出毒性；土壤pH、电导率随磷酸渣投加量的增加变化范围文持在0.5之内；土壤阳离子交换量随投加量增加而增大，说明投加磷酸渣后可提高土壤的保肥供肥性能和缓冲能力。28868
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关键词 磷酸渣 土壤 铅 固化剂
毕业论文设计说明书外文摘要
Title The study of remedying Pb in contaminated soils using phosphated residue.
Abstract
The changes of Pb forms and toxic leaching in contaminated soil after being added different amounts of phosphated residue as curing agent were investigated. The curing effect of phosphated residue was evaluated by measuring physical and chemical properties of soil including pH、conductivity and cation exchange capacity. The results suggested that Pb forms were changed after adding phosphated residue. Exchangeable, carbonate bound, oxidation state and organic bound contents of Pb were reduced with the increase of phosphated residue while residual content of Pb was increasing which indicated Pb transformed to a more stable form after adding phosphated residue; The TCLP reached EPA standard when addition amounts >5% which suggested the toxic leaching of Pb was reduced after adding phosphated residue; The varies of pH and conductivity maintained within the range of 0.5; Soil cation exchange capacity increased with the increase of phosphated residue adding amount, indicating that the application of phosphated residue can improve performance for fertilizer and buffering capacity of the soil.
Keywords phosphated residue, soil, lead, curing agent
目 次
1 引言 1
1.1 土壤重金属研究背景 1
1.1.1土壤重金属污染现状 1
1.1.2 土壤重金属 Pb的来源及危害 2
1.2 磷酸渣的来源和应用 2
1.2.1 磷酸渣的来源 2
1.2.2 磷酸渣的应用 2
1.3土壤重金属固定效果评价方法 3
1.3.1 毒性特性溶出程序（TCLP）法 3
1.3.2 多级提取法 3
1.4 本课题的目的与意义 4
1.5本课题的研究内容 4
2 实验过程 5
2.1 实验材料 5
2.1.1 实验用土 5
2.1.2 实验药品 5
2.1.3 实验仪器与设备 5
2.2 实验方法 6
2.2.1含铅土壤的配制 6
2.2.2磷酸渣固定铅污染土壤 6
2.2.3 固定效果评价 6
3 结果与讨论 10
3.1 固定化后土壤pH变化 10
3.1.1 pH变化分析 10
3.1.2 小结 10
3.2 固定化后土壤电导率变化 11
3.2.1 电导率对土壤指标的表示 11
3.2.2 固定化后土壤电导率分析 11
3.2.3 小结 12
3.3 固定化后土壤CEC变化 12
3.3.1 阳离子交换量的意义 12
3.3.2 结果分析 12