| 污染场地六价铬的还原和微生物稳定化研究 |
| 摘要点击 2953 全文点击 1377 投稿时间：2014-03-31 修订日期：2014-05-07 |
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| 中文关键词 Cr(Ⅵ) 稳定化 土壤 还原 微生物 |
| 英文关键词 Cr(Ⅵ) stabilization soil reduction microorganism |
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| 中文摘要 |
| 通过采集苏州某化工原址场地铬污染土壤，首先加入石硫合剂使大部分六价铬[Cr（Ⅵ）]还原，再加入营养液促进土著微生物大量生长，利用微生物还原稳定化土壤中的铬. 培养60 d后，通过毒性浸出、土壤中剩余Cr（Ⅵ）测定等实验确定稳定化效果，结果表明，加入5%营养液培养后，土壤毒性浸出液中Cr（Ⅵ）浓度由原来的8.26 mg ·L-1降低到0.26 mg ·L-1，降低了96.8%，总铬浓度由原来14.66 mg ·L-1降低到0.63 mg ·L-1，降低了95.7%. 另外，通过高锰酸钾氧化实验和灭菌实验确定稳定化的持久性，高锰酸钾氧化后，仅通过还原处理的土壤浸出液中Cr（Ⅵ）由8.26 mg ·L-1增加到14.68 mg ·L-1，而经稳定化后的土壤浸出液中Cr（Ⅵ）降低到2.68 mg ·L-1. 稳定化后的土壤样品经紫外灭菌，发现微生物消亡后，对稳定化效果没有显著影响. 因此，初步证明了高浓度高毒性的Cr（Ⅵ）污染土壤经初步还原后再经微生物稳定化治理是可行的，为Cr（Ⅵ）污染场地治理提供了一种高效低成本的修复技术. |
| 英文摘要 |
| Chromium(Ⅵ) contaminated soil samples were collected from a chemical plant in Suzhou. Firstly, the reduced soil was prepared by adding reagent (Stone-sulfure reagent) into polluted soil to transfer most chromium(Ⅵ) into chromium(Ⅲ), then a nutrient solution was introduced into the reduced soil, and the stabilized soil was obtained after 60 days culturing. The chromium(Ⅵ) content of the three kinds of soil was analyzed. The results showed that the chromium(Ⅵ) content in toxicity characteristic leaching liquid (TCLL) dropped by 96.8% (from 8.26 mg ·L-1 to 0.26 mg ·L-1), and the total chromium content dropped by 95.7% (from 14.66 mg ·L-1 to 0.63 mg ·L-1) after bioremediation in 5% nutrient solution. Additionally, the durability of chromium stabilization was tested by potassium permanganate oxidation and sterilization of microbe-treated soil. After oxidation, the chromium(Ⅵ) content in TCLL of the reduced soil was increased from 8.26 mg ·L-1 to 14.68 mg ·L-1. However, the content after bioremediation was decreased to 2.68 mg ·L-1. The results of sterilization demonstrated that the death of microbe had no significant effect on the stabilization of chromium. Consequently, the research in this paper demonstrated the feasibility of bioremediation of chromium(Ⅵ) polluted soil through reduction followed by stabilization/soilidification, and provided a technique with low cost but high efficiency. |
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