Degradation of carbon tetrachloride in the presence of zero-valent iron
Degradation of carbon tetrachloride in the presence of zero-valent iron
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DOI：
10.1039/c0em00039f
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发表时间：
2010-08-01
影响因子：
--
通讯作者：
LaFreniere, Lorraine
中科院分区：
文献类型：
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作者：
Alvarado, Jorge S.;Rose, Candace;LaFreniere, Lorraine
由于所需的条件和危险中间体的形成，通过厌氧和有氧生物修复和化学转化实现四氯化碳分解的努力取得的成功有限。最近，零价铁（ZVI）颗粒已被用于四氯化碳的原位修复，但成功有限。我们研究了一种改性的微粒产品，它将控释碳与ZVI相结合，用于刺激地下水中持久性有机化合物的原位化学还原。该产品结合了许多物理、化学和微生物过程，创造了非常强的还原条件，刺激了有机溶剂的快速、完全脱氯。原则上，ZVI微粒的有机成分是营养丰富和亲水性的，并且具有能够支持地下水环境中细菌生长的高表面积。在我们的实验中，我们发现随着细菌的生长，氧气被消耗，氧化还原电位降低到-600 mV。小的改性ZVI颗粒提供了相当大的反应性表面积，在这些条件下，直接刺激化学脱氯和污染区域的清洁，而不会积累不期望的分解产物。这项工作的目的是评估ZVI微粒在实验室和现场条件下减少四氯化碳的有效性。监测浓度和化学物理参数的变化，以确定有机产物在还原脱氯反应中的作用。实验室和现场研究。
Efforts to achieve the decomposition of carbon tetrachloride through anaerobic and aerobic bioremediation and chemical transformation have met with limited success because of the conditions required and the formation of hazardous intermediates. Recently, particles of zero-valent iron (ZVI) have been used with limited success for in situ remediation of carbon tetrachloride. We studied a modified microparticulate product that combines controlled-release carbon with ZVI for stimulation of in situ chemical reduction of persistent organic compounds in groundwater. With this product, a number of physical, chemical, and microbiological processes were combined to create very strongly reducing conditions that stimulate rapid, complete dechlorination of organic solvents. In principle, the organic component of ZVI microparticles is nutrient rich and hydrophilic and has high surface area capable of supporting the growth of bacteria in the groundwater environment. In our experiments, we found that as the bacteria grew, oxygen was consumed, and the redox potential decreased to values reaching -600 mV. The small modified ZVI particles provide substantial reactive surface area that, in these conditions, directly stimulates chemical dechlorination and cleanup of the contaminated area without accumulation of undesirable breakdown products. The objective of this work was to evaluate the effectiveness of ZVI microparticles in reducing carbon tetrachloride under laboratory and field conditions. Changes in concentrations and in chemical and physical parameters were monitored to determine the role of the organic products in the reductive dechlorination reaction. Laboratory and field studies are presented.