水流－化学耦合作用下结构性重金属污染土的宏微观动力学特性研究

项目名称： 水流－化学耦合作用下结构性重金属污染土的宏微观动力学特性研究

项目编号： No.51479194

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 水利工程

项目作者： 李振泽

作者单位： 中国科学院武汉岩土力学研究所

项目金额： 84万元

中文摘要： 结构性污染土在冲洗修复过程中存在极易发生结构坍塌与分散等结构演化的特征，导致严重的淤堵问题，极大制约土壤修复的效果。针对结构性污染土在原位冲洗修复中会发生淤堵和优先流等关键科学问题，本项目拟对水流-化学耦合作用下污染土的结构性演变规律及重金属离子的释放传输特性进行系统研究，通过开展单因素（水流或化学）与双因素耦合（水流和化学）作用等一系列试验来定量化研究结构性污染土的微观结构演化、渗流特性演变、重金属离子释放传输等关键因素，提出关键因素与水流-化学等变量的非线性变化关系，建立考虑结构性演化的污染土中重金属离子的反应性溶质运移模型，系统地揭示结构性重金属污染土的修复机制。研究成果不仅为污染场地原位修复的工程设计提供关键技术参数依据，同时为丰富和拓宽环境土力学理论，以及相关工程的安全性分析与环境质量评价提供理论和应用基础。

中文关键词： 结构性污染土；重金属；水流-化学耦合；解吸附；动力学

英文摘要： Polluted structural soils are ubiquitous in the near surface sedimentations, of which the soil structure is easily collapsible and disaggregated to cause significant clogging of pore space that further leads to restrained efficiency in soil remediation. In regard of the clogging and preferential flow occurring in the course of in-situ soil washing, this project is aimed at researches on the structural evolution and heavy metal description of polluted soils under coupled hydraulic-chemical effects, by the means of experimental studies on monofactor (hydraulic or chemical) and bifactors (hydraulic and chemical) against the impacts on key parameters such as microscale structural change, permeability and heavy metals' mobilization. Nonlinear empirical formula is to be proposed about the correlationship between variables (hydraulic and chemical) and key parameters. A reactive solute transport model for polluted structural soil is to be established in view of its structural variations. This project will help to unravel the remedial mechanism for polluted structural soils. The research outcomes will provide critical technical criteria for the appropriate design of in-situ remediation of polluted field, as well as theoretical and applicable support to the expansion of environmental soil mechanics and risk analysis and environmental quality assessment for the relevant engineering projects.

英文关键词： structural polluted soil;heavy metal;hydro-chemical coupling;desorption;kinetics