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

工业溶剂如三氯乙烯（TCE）、四氯乙烯（PCE）和其他氯化有机化学品在20世纪70年代初被认为是地下水的重要污染物。滑铁卢大学率先使用颗粒铁作为可原位渗透的“壁”来降解这些化合物，并且在过去的几年中，该主题的研究得到了NSERC工业研究主席（IRC）的支持。这项建议包括六个分项目，主要目的是评价从早期实验室试验中获得的一些有希望的结果在实地的适用性。将开发一种新型的原位流动柱装置，该装置应提供原位颗粒铁可渗透反应屏障（PRB）性能的准确表示。该装置将用于在自然条件下检查氯化丁烯、丁二烯和硝基甲苯这两类化合物的降解潜力。降解动力学、降解产物、竞争效应、原位温度的影响以及地下水的无机化学成分将被检查。在进一步的研究中，将对先前为预测长期性能而开发的数学模型进行测试，以对照已运行超过五年的PRB的实际性能。另一项研究涉及用于地上处理的原型反应堆的测试和性能。实验室试验表明，添加少量酸可非常有效地防止流经反应器的金属催化剂钝化。这将在安装在滑铁卢一个商业地点的原型反应堆中进行进一步评估。

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.