铬污染毒性土壤清洁修复研究进展与综合评价

综述了土壤中铬的来源,土壤中铬的赋存形式及其提取方法,国内外铬污染土壤修复技术研究动态,探讨了铬污染土壤修复的发展方向,并对现阶段主要的修复技术,诸如客土法、稀释法、固定化和稳定化、化学还原、土壤淋洗、电动修复、生物修复等进行了详细介绍,进而对各种修复方法的优缺点进行了对比、归纳和评价,针对不同特点、性质的铬污染土壤给出修复方法的建议,为清洁高效修复铬污染土壤提供参考. 

Research progress on remediation technologies of chromium-contaminated soil: a review

With the rapid economic development in China, more areas of industrial contaminated soil has been left unused because of industrial relocation or environmental protection. Considering the chromium (salt) industrial wasteland, the area of chromium-contaminated soil caused by the accumulation of chromium slag has reached 5 million square meters, and its direct utilization can result in health hazards to the public and threaten the environment. Therefore, it is of great practical significance to carry out research on economic, efficient, and clean methods for chromium-contaminated soil remediation. In this paper, the origin and occurrence of the chromium in soil, their extraction methods, and the research progress of chromium-contaminated soil in and outside China were reviewed. First, the occurrence of the chromium in soil was discussed. It is found that Cr exists predominantly in Cr(Ⅲ) and Cr(Ⅵ) oxidation states, whereby Cr(Ⅲ) is the more stable; under most prevailing environmental conditions Cr(Ⅵ) is rapidly reduced to Cr(Ⅲ). The methods of extracting chromium from soil were presented, including Tessier sequential extraction procedure and the European Community Bureau of Reference(BCR) three-step sequential extraction procedure, and then the two continuous extraction methods were compared and evaluated. Afterward, the remediation techniques of chromium-contaminated soil were systematically reviewed, including engineering physical repair methods, dilution methods, immobilization and stabilization, chemical reduction, electrokinetics repair, and bioremediation. The advantages and disadvantages of the various remediation techniques were compared, summarized, and evaluated. The developments of chromium-contaminated soil remediation technologies in the future were also explored, including the clean remediation technologies, combination of several remediation technologies, and novel nano-remediation materials. Accordingly, suggestions for the remediation of different chromium-contaminated soils were presented, which can provide references for clean and efficient remediation of chromium-contaminated soils.