SBIR PHASE I: Enhanced Subsurface Injection of Chlorinated Solvent Degrading Microorganisms

这个小企业创新研究第一阶段项目将探索如何处理地下环境（如含水层）中的氯化溶剂污染。 氯化溶剂，如三氯乙烯，是特别普遍的含水层污染物。 根据污染程度，其物理特性可能导致它们以DNAPLs形式出现并吸附到含水层沉积物中，这使得它们难以通过泵送和处理方法进行补救。 对于这些共代谢污染物，土著细菌种群的生物降解可能受到缺乏合适的土著种群或诱导共底物降解活性的限制。 对于许多地点，特别是含水层污染，补救将需要生物强化或在地下引入降解细菌。 EQUIPROGEN已经开发出专门用于氯化溶剂原位修复的细菌。 这些菌株是粘附缺陷的增强运输;它们组成性地表达TCE降解酶，消除了诱导共底物的需要;并且它们可以与大量储能聚合物一起生长以延长降解。 然而，这些菌株的应用可能局限于具有广泛DNAPL污染的地点。 游离产物氯化溶剂对这些细菌有毒。 为了扩大这些高度专业化的生物体的应用，我们建议将这些生物体与泡沫技术相结合，该泡沫技术将起到分散微生物以及DNAPLs的作用，从而降低它们的毒性。这种泡沫技术还可以提供用于提供营养物和氧气以延长引入的菌株的降解活性的机制。 拟议工作的成功示范将产生一种就地生物强化技术，用于处理即使是污染最严重的含水层。 这一技术具有广泛的适用性;氯化溶剂是政府和私人场所常见的地下水污染物。

This Small Business Innovation Research Phase I project will explore ways to treat chlorinated solvent contamination in subsurface environments such as aquifers. Chlorinated solvents, like trichloroethylene (TCE), are particularly prevalent aquifer contaminants. Depending on the degree of contamination, their physical properties may cause them to occur as DNAPLs and sorb to aquifer sediments, which make them difficult to remediate by pump-and-treat methods. For these cometabolic contaminants, biodegradation by indigenous bacterial populations may be limited by the lack of a suitable indigenous population or inducing cosubstrates for degradative activity. For many sites, especially aquifer contamination, remediation will require bioaugmentation or the introduction of degradative bacteria into the subsurface. ENVIROGEN has developed bacteria specifically for the in situ remediation of chlorinated solvents. These strains are adhesion-deficient for enhanced transport; they express TCE-degrading enzymes constitutively, eliminating the need for inducing cosubstrates; and they can be grown with large amounts of energy storage polymers for prolonged degradation. The application of these strains, however, may be limited at sites that have extensive DNAPL contamination. Free product chlorinated solvents are toxic to these bacteria. To broaden the applications for these highly specialized organisms, we propose to combine these organisms with a foam technology which will act to disperse the microorganisms as well as the DNAPLs, thereby reducing their toxicity. This foam technology may also provide a mechanism for providing nutrients and oxygen to extend the degradative activity of the introduced strains. The successful demonstration of the proposed work will result in an in situ bioaugmentation technology for treating even the most highly contaminated aquifers. This technology is broadly applicable; chlorinated solvents are common groundwater contaminants at both government and private sites.