CAJ | 학술논문

　　重金属污染企业搬迁遗留场地的重金属污染问题是当前城市土地安全开发需解决的迫切环境问题。以广州市某钢铁企业搬迁遗留场地重金属污染土壤处置为例，系统研究污染重金属晶体结构化固定过程机制。对遗留场地土壤通过采样调查发现，在场地某些区域的土壤中，重金属Ni和Cd的浓度超过GB 15618-1995《土壤环境质量标准》二级标准，二次开发存在一定的环境风险。通过研发以氧化铝为基质的黏土固定剂，以一定比例与污染土壤混合后压实成型，在1100℃的温度下煅烧，通过X-射线衍射研究发现，烧结体中重金属以尖晶石晶体结构成分的形式固定。进一步采用TCLP毒性浸出程序研究烧结体中重金属的浸出风险，结果发现，烧结体中滤出液中重金属浓度均远低于GB 3838-2002《地表水环境质量标准》三类水标准值，获得烧结体中重金属浸出风险低。实现了重金属污染土壤的无害化处置，对于目前重金属污染企业遗留场地土壤处置具有重要意义。
　　중금속오염기업반천유류장지적중금속오염문제시당전성시토지안전개발수해결적박절배경문제。이엄주시모강철기업반천유류장지중금속오염토양처치위례，계통연구오염중금속정체결구화고정과정궤제。대유류장지토양통과채양조사발현，재장지모사구역적토양중，중금속Ni화Cd적농도초과GB 15618-1995《토양배경질량표준》이급표준，이차개발존재일정적배경풍험。통과연발이양화려위기질적점토고정제，이일정비례여오염토양혼합후압실성형，재1100℃적온도하단소，통과X-사선연사연구발현，소결체중중금속이첨정석정체결구성분적형식고정。진일보채용TCLP독성침출정서연구소결체중중금속적침출풍험，결과발현，소결체중려출액중중금속농도균원저우GB 3838-2002《지표수배경질량표준》삼류수표준치，획득소결체중중금속침출풍험저。실현료중금속오염토양적무해화처치，대우목전중금속오염기업유류장지토양처치구유중요의의。
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.