生态环境学报Issue(6)：1058-1062,5.
基于矿物晶体结构的场地重金属污染土壤结构化固定处置
Structural stabilization of contaminated heavy metals in soils based on the crystal structure mechanism of soil minerals
摘要
Abstract
The soil contamination by heavy metals left at the sites of factories manufacturing related heavy metals has received increased attention recently. The soils at these sites need to be treated in order to be environmentally safe before being developed for other uses. In this study, the mechanism of structural stabilization of heavy metals in contaminated soils based on the crystal structure of soil minerals was systematically investigated, with the target contaminated soils at a site left by an iron and steel factory in Guangzhou City. Initially, concentrations of heavy metals in the sites were investigated, which revealed levels of Ni and Cd to be at higher concentrations than the levels of the second standard in Soil Environmental Quality Standard of China (GB 15618-1995). Therefore, it is considered to be a potential health risk to anyone who might live at the site. A new stabilization agent utilizing clays as the core component was developed. The stabilization agent was mixed with the contaminated soils at designed weight ratios, and the mixture was then compacted, before being sintered at 1 100 ℃. The X-ray diffraction (XRD) study of the sintered solids shows that the contaminated heavy metals were incorporated into the sintered solids as the components of spinel structure. The leaching risk of the stabilized heavy metals in the sintered solids were further evaluated with the toxicity characteristic leaching procedure (TCLP), and it was found that concentrations of heavy metals in the leaching solution were much lower than the third standard concentration levels of Surface Water Environment Quality Standard of China. The results indicate that the contaminated heavy metals in soils were structurally stabilized in the sintered solids and there was a much lower risk of secondary pollution of the stabilized heavy metals when exposed to the natural environment. The obtained results are important for developing treatment methods to render harmless soils contaminated with heavy metals. This is also expected to play an important role in the field of soil remediation, especially for the site soils left in urban areas by relocated factories.关键词
工业搬迁场地/重金属污染/土壤矿物/尖晶石/结构化固定Key words
Industrial relocation site/Heavy metal pollution/Soil mineral/Spinel/Structured fixed分类
资源环境引用本文复制引用
高原雪,张玉娇,陈柏迪,刘传平,陈迪云,刘承帅..基于矿物晶体结构的场地重金属污染土壤结构化固定处置[J].生态环境学报,2013,(6):1058-1062,5.基金项目
国家自然科学基金项目(41171364)；广州大学“挑战杯”学生作品校级资助项目；广东省科技计划项目(2012A030700011；2011B030900005) （41171364）
