Remediation of organic-contaminated groundwater with granular iron: Small-scale field tests

1970年代初，三氯乙烯（TCE）、四氯乙烯（PCE）和其他氯化有机化学品等工业溶剂被认为是重要的地下水污染物。 使用粒状铁，配置为原位可渗透的“墙”，用于降解这些化合物是在滑铁卢大学开创的，在过去的几年里，关于该主题的研究得到了NSERC工业研究主席（IRC）的支持。 该提案包括六个分项目，主要是评估从早期实验室测试中获得的几个有希望的结果的现场适用性。 一种新的原位流通柱装置将被开发，应提供一个准确的表现，在原位粒状铁可渗透反应性屏障（PRB）。 该装置将用于在自然条件下检查两类化合物（氯化丁烯、丁二烯和硝基甲苯）的降解潜力。 将研究降解动力学、降解产物、竞争效应、原位温度效应以及地下水的无机化学成分。 在进一步的研究中，先前为预测长期表现而开发的数学模型将与已运营超过五年的PRB的实际表现进行测试。 另一项研究涉及用于地面处理的原型反应器的测试和性能。 实验室试验表明，加入少量的酸在防止流通式反应器中所含金属催化剂钝化方面非常有效。 这将在安装在滑铁卢商业场所的原型反应堆中进行进一步评估。 研究结果应提供关于各种污染物的现场行为的重要和实用信息，从而有可能扩大该技术的适用范围。 原位柱装置是新颖的，具有市场潜力，并且反应器，如果成功的话，可以为污染水的地上处理提供重要的和高度可销售的技术。

Industrial solvents such as trichloroethene (TCE) tetrachlorethene (PCE) and other chlorinated organic chemicals were recognized as significant groundwater contaminants in the early 1970s.  The use of granular iron, configured as an in situ permeable "wall", for degrading these compounds was pioneered at the University of Waterloo, and for the past several years, research on the topic has been supported by an NSERC Industrial Research Chair (IRC).  This proposal includes six sub-projects primarily directed at evaluating the field applicability of several of the promising results obtained from earlier laboratory tests.  A novel in situ flow-through column device will be developed that should provide an accurate representation of the performance of an in situ granular iron permeable reactive barriers (PRB).  This device will be used to examine, under natural-field conditions, the potential for degradation of two classes of compounds, chlorinated butenes and butadienes and nitro toluenes.  Kinetics of degradation, degradation products, competitive effects, and the effect of in situ temperature, and inorganic chemical composition of the groundwater will be examined.  In a further study, a mathematical model previously developed for predicting the long-term performance will be tested against the actual performance of a PRB that has been operating for a period in excess of five years.  An additional study concerns the testing and performance of a prototype reactor for above-ground treatment.  Laboratory tests have shown the addition of a small amount of acid to be highly effective in preventing the passivation of metal catalysts contained in flow through reactors.  This will be further evaluated in a prototype reactor installed at a commercial site in Waterloo.   The results should provide important and practical information concerning the field behaviour of various contaminants, potentially broadening the applicability of the technology.  The in situ column device is novel, with market potential, and the reactor, if successful could provide an important and highly marketable technology for above ground treatment of contaminated water.