地聚物固封重金属污染红土的宏微观机制及环境耐久性

Considering the unique feature of lateritic soil and its special forming conditions, a metakaolin-based geopolymer is adopted as the solidification/stabilization agent for heavy metal contaminated lateritic soil. Multi-scale research on the lateritic soil stabilized with geopolymer will be established from the microstructure investigation to the engineering properties testing. The research includes: (1) the micro-mechanism on the geopolymeric stabilization of heavy metal contaminants in lateritic soil; (2) the macro-mechanism and behavior of geopolymer stabilized lateritic soil; (3) the impacts of dry-wet cycling on the durability of geopolymer stabilized lateritic soil; (4) the influences of rainy conditions on the durability of geopolymer stabilized lateritic soil; (5) evaluations on the environmental durability of geopolymer stabilized lateritic soil. Through these research, this project tries to answer: (1) the micro-macro mechanism of the geopolymeric solidification/stabilization of heavy metal contaminated lateritic soil; (2) the influence of forming conditions on the geopolymeric stabilized lateritic soil; (3) the multi-scale interaction between geopolymer, heavy metal and oxide colloid in lateritic soil. The findings of this project could be used in the remediation of heavy metal contaminated land in laterite districts.

针对红土的特殊性质及形成环境，采用环保型地聚物材料固封重金属污染红土。通过微观测试手段和宏观试验技术相结合的方式，对地聚物固封重金属污染红土的基础理论进行微观机理至宏观特性的多尺度研究。主要研究内容有：(1) 地聚物固封重金属污染红土的微观机制；(2) 地聚物固封重金属污染红土的宏观表征；(3) 干湿循环对地聚物固封重金属污染红土的宏微观影响；(4) 雨水溶蚀对地聚物固封重金属污染红土的宏微观影响；(5) 地聚物固封重金属污染红土的环境耐久性。通过以上研究，拟解决以下关键问题：(1)地聚物封闭并固化重金属污染红土的机制；(2)红土形成环境影响地聚物固封重金属污染红土的机理及规律；(3)地聚物-重金属-土中胶体相互作用的多尺度体现。成果有望应用于红土地区重金属污染场地的治理与开发重利用。