土壤聚合物对几种重金属离子固化效果的研究

土壤聚合物是一种新型的无机聚合物,其分子链由Si、O、Al等以共价键或离子键连接而成,形成网络结构,对重金属有较强的固定作用.本文试图利用土壤聚合物固化铜、锌、铅三种重金属离子,实现资源化利用.实验以固化体抗压强度和浸出毒性作为性能表征量,结果表明:土壤聚合物对不同重金属的固化有各自的极限浓度,Cu2 、Zn2 、Pb2 的理想固化量分别为0.9%、1%、2%;若固化过程中添加一定量的高炉矿渣,则可以提高固化体的抗压强度.本文通过土壤聚合物固化体SEM分析,从固化体微观结构的形态来阐述土壤聚合物宏观上的优越表现.

STUDY ON THE EFFECT OF GEOPOLYMERS ON THE IMMOBILIZATION OF HEAVY METALS

Geopolymer is a new-type inorganic polymer.Its molecular chain is made up of Si,O and Al by covalent bond and electrovalent bond.Geopolymer is a kind of zeolitelike inorganics with net structure,which has a strong fixing power toward heavy metal ions.Geopolymers to immobilize heavy metals such as Cu2 ,Zn2 and Pb2 were investigated in this paper.It was found that geopolymers are able to immobilize heavy metals selectively.It was demonstrated that there are different desired qualities to different heavy metals.It is shown that there are different limits of addition for different heavy metals based on compressive strength and leaching toxicity to reclaim and reutilize,their respective optimum addition amounts of Cu2 ,Zn2 ,Pb2 are 0.9%,1% and 2%,respectively.It is found that adding a certain amount of slag to metakaolin will help to raise the compressive strength.Due to the microstructural mechanisms of heavy metal immobilization,the matrix containing 0.5% Pb2 was assessed by Scanning Electron Microscopy(SEM).