含磷物质钝化修复重金属复合污染土壤.pdf

西安科技大学 硕士学位论文 含磷物质钝化修复重金属复合污染土壤 姓名：魏晓欣 申请学位级别：硕士 专业：环境科学 指导教师：代革联 @ 论文题目：含磷物质钝化修复重金属复合污染土壤 专 业：环境科学 硕 士 生：魏晓欣 （签名） 指导教师：代革联 （签名） 摘 要 化学钝化修复是一种以降低风险为目的的污染土壤治理方法，通过添加活性材料， 以调节和改变污染物在土壤中的物理化学性质，使其产生吸附、络合、沉淀、离子交换 和氧化还原等一系列反应，降低其有效性及生物可利用性，达到修复效果近年来，用 含磷材料修复污染土壤主要集中在重金属铅上，而实际土壤重金属污染往往一个多金属 并存的复合污染，因此研究含磷材料修复重金属复合污染土壤更具有实际意义 本论文运用重过磷酸钙磷肥（TSP）和磷灰石矿粉（PR）材料，修复重金属铅、铜、 锌、镉复合污染的土壤，目的是减小重金属的有效性，降低其生物可利用性采用重金 属有效性提取（0.01MCaCl2） 、毒性淋溶提取(toxicity characteristic leaching procedure， TCLP)、生物可利用性提取（physiologically based extraction test，PBET）以及柱淋溶实 验评价重金属复合污染土壤的修复效果； 借助 Visual MINTEQ 化学形态模型探讨含磷物 质修复污染土壤中重金属的可能机理。

主要研究结果如下： （1）PR、TSP 和 PR+TSP 三种磷处理均有效地降低土壤 CaCl2、TCLP 和 PBET 提 取态的 Pb 含量，其中 CaCl2和 TCLP 提取态的 Pb 分别降低 20~80%和 62~86%，三种磷 处理的效率大小依次为 TSPPR+TSPPR；同样，磷处理对 Cd 也有一定的稳定效果， 如 TCLP 提取态的 Cd 下降达 32%，三种磷处理的效率大小依次为 TSPPR+TSPPR 就 Cu 和 Zn 而言，其修复效果依赖于 P 处理方式和评价方法PR 均能有效地降低土壤 CaCl2和 TCLP 提取态的 Cu 和 Zn；尽管 TSP 能降低 TCLP 提取态的 Cu 和 Zn，但增加 了土壤 CaCl2提取态的 Cu 和 Zn；而 PR+TSP 复合处理均增加了土壤 CaCl2和 TCLP 提 取态的 Cu 和 Zn （2） 随着柱淋溶量的增大， PR 处理的淋滤液中 P 没有明显变化， 而 TSP 和 PR+TSP 处理的淋滤液的 P 在淋洗液为 2 个 PV 时有显著增加；三种磷处理能够很好的固定土壤 中的 Pb，降低 Pb 的淋出量，对重金属 Zn 和 Cu 的固定效果一般，甚至 TSP 和 PR+TSP 处理增加了 Zn 的淋溶性，三种重金属淋溶活性顺序为 CuZnPb。

（3）含 P 物质能使 Pb 稳定化主要是由于形成了磷酸铅沉淀而 Cu 和 Zn 的稳定 化可能与表面吸附和络合作用有关，主要受 pH 的影响 （4）磷肥和磷矿粉修复重金属 Cu、Zn、Pb、Cd 复合污染土壤，对 Pb 的修复效果 较为理想，其次是 Cd，对于 Cu 和 Zn 的修复效果一般，甚至某些处理会带来负作用， 即它们的活性反而有可能增强因此，在用含磷材料修复这些重金属复合污染土壤时， 应十分关注这一现象， 即某些处理会降低 Pb 和 Cd 的有效性但同时有可能增加 Cu 和 Zn 的有效性，增加其环境生态风险 关 键 词：重金属；复合污染；土壤；含磷物质；钝化修复 研究类型：应用研究 Subject : Phosphate-induced Immobilization of Heavy Metals in Multi-metal Contaminated Soils Specialty : Environmental Science Name : Wei Xiaoxin （（Signature）） Instructor : Dai Gelian （（Signature）） ABSTRACT Chemical inactivation is a cost-effective method for remediation of metal contaminated soil, which is based on reduction of metal availability through formation of amendment -induced insoluble metal precipitates. Application of phosphorus-bearing materials in remediation of contaminated soil has been greatly receiving more attention, but it is mostly focused on Pb immobilization. However, real soil contaminated with metal is often a system of multi-metal combined pollution. Therefore, it has more practical significances to apply phosphorus-bearing materials in remediation of the multi-metal contaminated soils. The expriment was conducted by using phosphate rock (PR) and phosphorus fertilizer (TSP), alone or in combination, to induce immobilization of Pb, Cd, Zn and Cu in a multi-metal combined contaminated soil. The treatment effectiveness was evaluated through CaCl2 extraction, toxicity characteristic leaching procedure (TCLP), physiologically based extraction test (PBET), and column leaching expriment. The results show that: (1) All three P treatments (PR, TSP, and PR+TSP) were effective in reducing Pb concentrations in CaCl2, TCLP, and PBET extracts. The concentrations of Pb in CaCl2 and TCLP extracts were reduced by 20~80% and 62~86%, respectively. Effects of three P amendments on Pb immobilization followed a trend of TSP PR+TSP PR. Similarly, three P treatment also effectively immobilize Cd, with Cd in TCLP extract being reduced by 32%. As for Cu and Zn, the treatment effectiveness depends on the P-bearing material nature and evaluation methods. PR was effective in reducing Cu and Zn in CaCl2 and TCLP extracts. In spite of reduction of TCLP-Cu and -Zn, TSP treatment increased Zn and Cu concentrations in CaCl2 extract. PR+TSP treatment increased Zn and Cu concentrations in both CaCl2 and TCLP extracts. (2) As the soil column leachate increased, a breakthrough of P was observed at more than two pore volume of leachate in the TSP and PR+TSP treatments, but P leaching was low and remained unchanged in the PR treatment. All three P treatment reduced Pb leaching, bu the leaching of Cu and Zn were elevated in the TSP and PR+TSP treatments. The order of the total released amount of the heavy metals was Cu Zn Pb. (3) Immobilization of Pb was probably attributed to formation of Pb phosphate precipitate; while surface adsorption and complexation may be responsible for inactivation of Cu and Zn. (4) Overall, all three P treatments were effective in immobilizing Pb and Cd, but less for Cu and Zn; and even the availability of Cu and Zn was elevated by some P treatments. This case should be paid more attention and may be avoided by application of P-bearing materials in combination with other amendments, e.g., CaCO3 Keywords：：Heavy metals Combined pollution Soil Immobilization Phosphorus-bearing materials Thesis ：：Applied Research 1 绪论 1 1 绪论 1.1 研究背景与意义 1.1.1 研究背景 土壤是人类赖以生存的物质基础，是人类不可缺少、不可再生的自然资源。

土壤污 染具有隐蔽性与滞后性、累积性与地域性、不可逆转性和治理难、周期长等特点土壤 重金属污染是指人类活动将重金属加入到土壤中，致使土壤中重金属含量明显高于原有 含量，并造成生态环境恶化的现象[1]其污染来源主要是由采矿、冶炼、电镀、化工、 电子、制革染料等工业生产的三废以及污灌、农药化肥的不合理施用等引起的[2]重金 属通常包含元素原子密度大大超过 6g/cm3的金属和非金属（例如 As 砷，B 硼，Se 硒） 这一类包含生物所必须的（Co 钴 Cu 铜 Cr 铬 Mn 锰 Zn 锌）和不需要的（Cd 镉 Pb 铅 Hg 汞）元素植物，动物和人类的营养对这些必。