Characterization of Chromium Waste Form Based on Biocementation by Microbacterium sp. GM-1

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• 作者：Limei Lun ; Dongwei Li ; Yajie Yin ; Dou Li ; Guojing Xu…
• 刊名：Indian Journal of Microbiology
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：56
• 期：3
• 页码：353-360
• 全文大小：671 KB
• 刊物主题：Microbiology; Medical Microbiology;
• 出版者：Springer India
• ISSN：0973-7715
• 卷排序：56

文摘

This paper demonstrated a biocementation technology for chromium slag by strain GM-1, a calcifying ureolytic bacterium identified as Microbacterium, based on microbially induced calcium carbonate. The characterization of Microbacterium sp. GM-1 was assessed to know the growth curve in different concentrations of Cr(VI). Microbacterium sp. GM-1 was tolerant to a concentration of 120 mg/L Cr(VI). Chromium waste forms were prepared using chromium, sand, soil and bacterial culture. There we had three quality ratios (8:2:1; 8:1:1; 8:2:0.5) of material (chromium, sand and soil, respectively). Bacterial and control chromium waste forms were analyzed by thermal gravimetric analyzer. All bacterial forms (8:2:1; 8:1:1; 8:2:0.5 J) showed sharp weight loss near the decomposition temperature of calcium carbonate between 600 and 700 °C. It indicated that the efficient bacterial strain GM-1 had induced calcium carbonate precipitate during bioremediation process. A five step Cr(VI) sequential extraction was performed to evaluate its distribution pattern in chromium waste forms. The percentage of Cr(VI) was found to significantly be decreased in the exchangeable fraction of chromium waste forms and subsequently, that was markedly increased in carbonated fraction after biocementation by GM-1. Further, compressive strength test and leaching test were carried out. The results showed that chromium waste forms after biocementation had higher compressive strength and lower leaching toxicity. Additionally, the samples made of 8:1:1 (m/m/m) chromium + sand + soil were found to develop the highest compressive strength and stand the lowest concentration of Cr(VI) released into the environment.KeywordsChromiun slagCr(VI)BiorecementationCalcium carbonateWaste form