Dehalogenation of chlorinated hazardous organics

开发高效液相氯代有机物修复技术，同时了解其对健康和营养的影响，是解决超级基金场地问题的关键。与氧化技术相比，还原脱卤技术可以提供完全的脱毒。如果降解途径得到控制，还原过程（零价铁、维生素B12）可导致HC1、水和非卤化挥发性有机物的完全脱卤。在环境温度条件下，了解和控制降解途径以在短停留时间（小于1小时）内产生无害的降解产物尚未完成。这项工作的总体目标是研究还原剂形态对产物分布和速率的作用，确定中间副产物的降解速率（氯乙烯是一个例子），并关闭降解过程周围的元素平衡（特别是C和C1）。研究的还原剂体系包括零价铁颗粒、零价纳米级金属颗粒及其复合材料、高表面积/高孔隙率铁包覆复合材料和新型固定化维生素B12衍生物（电聚合）体系。维生素B12可以通过在聚合物薄膜中加入活性复合物和利用电化学技术再生活性入口来提高总体速率。为了开发高效的修复系统，需要深入研究表面形貌和开发高活性材料在减少反应时间和提高中间产物降解率方面的作用。除了开发高度通用的氯化有机物脱卤速率模型外，我们还计划建立反应表面形貌（通过ARM和XPS方法）随反应时间的变化。

The development of highly efficient liquid phase remediation technologies for chlorinated organics and the simultaneous understanding of health and nutrition effects are critical for solving Superfund site problems. Reductive dehalogenation technologies, in contrast to oxidative techniques, are known to provide complete detoxification. Reductive processes (zero-valent iron, vitamin B12) can lead to complete dehalogenation to HC1, water and non-halogenated volatile organics if the degradation pathways are controlled. Understanding and control of the degradation pathways to yield innocuous degradation products in short residence times (less than 1 hour) under ambient temperature conditions has yet to be accomplished. The overall objectives of this work are to study the role of the reductive agent morphology on the product distribution and rate, establish the degradation rates of intermediate byproducts (vinyl chloride is an example), and close the elemental balances (particularly C and C1) around the degradation processes. The reductive agent systems to be investigated are zero-valent iron particles, zero-valent nanoscale metal particles and composites, high surface area/high porosity iron coated composites, and novel immobilized vitamin B12 derivative (electropolymerization) systems. With Vitamin B12 the overall rates can be enhanced by incorporating the active complex in polymer films and by using electrochemical techniques to regenerate the active enter. The role of surface morphology and the development of highly reactive materials to reduce reaction time and to enhance intermediate product degradation rates needs thorough investigation for the development of highly efficient remediation systems. In addition to the development of highly versatile models for chlorinated organics dehalogenation rates, we plan to establish the reactive surface morphology (by ARM and XPS methods) changes as a function of reaction time.