粘土介质中多组分污染物运移规律、控制机理及试验模拟

Prediction on the transport of contaminants in the clay medium is a pressing issue in the treatment of contaminated soil and the evaluation of contaminated sites. Investigations on the variable basic properties of the clay and interactions of multi-component contaminant solute are the key scientific problems. Artificially contaminated clay was prepared for laboratory experiments and numerical simulations to investigate the migration rule and controlled mechanism of the multi-component contaminants in the clay. Firstly, the variations of engineering properties of clay due to the interactions of multi-component pollutant using experimental tests provide the necessary design parameters; Secondly,the deformation-coupled migration rule equation of single-component is presented, which is solved by the homotopy analysis method and extended to the multi-component contaminants conditions for revealing the real rule of pollutants migration; thirdly, soil column test system was conducted to simulate complex contaminant migration for calibrating the theoretical solution and related parameters; Finally, the curing agents, including cement, magnesia, et al, are used to stabilize contaminated clay, which optimize Solidification/stabilization methods. The long-term curing strength of the stabilized contaminated clay was presented through wet-dry cycle tests.

如何预测污染物在粘土介质中的迁移规律是污染土治理、污染场地评价等实际工程中亟待解决的难题，掌握粘土基本特性的变化特征及多组分污染物溶质之间相互影响规律是解决这一难题的核心科学问题。本项目以人工制备的污染粘土为研究对象，通过室内试验和理论分析，着重研究粘土中多组分污染物的迁移规律及控制机理。首先，试验研究多组分污染物作用下粘土的工程性质变化规律，为污染土的分析提供必要的指标参数；其次，提出单一组分污染物迁移规律的变形耦合控制方程，运用同伦分析法求解并拓展到多组分污染物工况，初步揭示粘土中多组分污染物迁移规律；第三，利用自制土柱试验系统模拟复杂条件下多组分污染物的迁移特征，对理论解答及相关参数进行校核，深入掌握污染物迁移规律及其计算方法；最后，利用水泥、氧化镁等固化剂进行污染土的固化试验，揭示复杂污染粘土的固化/稳定机制，优化配合比和处治方法，并通过干湿循环等试验揭示固化污染土长期稳定性特征。

粘土是垃圾填埋场及其垫层系统的重要组成部分也是众多污染场地地基土的主要类型，开展粘土介质中多组分污染物迁移规律、控制方法，对于污染场地的评估与再利用具有重要的意义。本项目通过室内试验、理论分析和数值计算等手段开展了研究工作。通过人工配置污染粘土，系统研究了重金属、盐类和有机物类污染物对粘土基本性质的影响。考虑地基土层状特性和污染物的多组分特征，提出了单一组分污染物迁移规律的变形耦合控制方程，获取了考虑变形作用的层状地基土污染物运移计算模型及其解答；引入同伦分析法，求解出了粘土中多组分污染物迁移模型理论解答，并对变系数等复杂条件下的理论解答进行了深入分析。最后对重金属、盐类和有机物类污染粘土进行固化稳定试验，得出了强度变形规律，分析了其微观机构特征和作用机理，揭示了复杂污染粘土的固化/稳定机制。本研究已发表学术论文14篇，其中SCI、EI收录10篇，另有在审论文3篇；申请国家发明专利5项；培养硕士研究生8位。圆满完成预定的各项目标。