Papassiopi Nymphodora, Kontoyianni Athina, Vaxevanidou Katerina, Xenidis Anthimos
School of Mining and Metallurgical Engineering, National Technical University of Athens (NTUA), Zografos Campus, GR-157 80, Athens, Greece.
Sci Total Environ. 2009 Jan 1;407(2):925-36. doi: 10.1016/j.scitotenv.2008.09.020. Epub 2008 Oct 21.
The iron reducing microorganism Desulfuromonas palmitatis was evaluated as potential biostabilization agent for the remediation of chromate contaminated soils. D. palmitatis were used for the treatment of soil samples artificially contaminated with Cr(VI) at two levels, i.e. 200 and 500 mg kg(-1). The efficiency of the treatment was evaluated by applying several standard extraction techniques on the soil samples before and after treatment, such as the EN12457 standard leaching test, the US EPA 3060A alkaline digestion method and the BCR sequential extraction procedure. The water soluble chromium as evaluated with the EN leaching test, was found to decrease after the biostabilization treatment from 13 to less than 0.5 mg kg(-1) and from 120 to 5.6 mg kg(-1) for the soil samples contaminated with 200 and 500 mg Cr(VI) per kg soil respectively. The BCR sequential extraction scheme, although not providing accurate estimates about the initial chromium speciation in contaminated soils, proved to be a useful tool for monitoring the relative changes in element partitioning, as a consequence of the stabilization treatment. After bioreduction, the percentage of chromium retained in the two least soluble BCR fractions, i.e. the "oxidizable" and "residual" fractions, increased from 54 and 73% to more than 96% in both soils.
对铁还原微生物棕榈酸脱硫单胞菌作为铬酸盐污染土壤修复潜在生物稳定剂进行了评估。棕榈酸脱硫单胞菌用于处理人工污染有两种浓度六价铬（即200和500毫克/千克）的土壤样品。通过对处理前后的土壤样品应用几种标准提取技术来评估处理效率，如EN12457标准浸出试验、美国环保署3060A碱性消解方法和BCR连续提取程序。用EN浸出试验评估的水溶性铬，发现在生物稳定处理后，对于每千克土壤分别被200毫克和500毫克六价铬污染的土壤样品，其含量从13毫克/千克降至低于0.5毫克/千克，从120毫克/千克降至5.6毫克/千克。BCR连续提取方案虽然不能提供受污染土壤中初始铬形态的准确估计，但被证明是监测稳定处理后元素分配相对变化的有用工具。生物还原后，两种最难溶的BCR组分（即“可氧化”和“残留”组分）中保留的铬百分比，在两种土壤中均从54%和73%增加到超过96%。
