SBIR Phase II: Membrane Hydrogen Dissolution for Bioremediation of High Strength Nitrate Waste

这个小企业创新研究第二阶段项目将扩展第一阶段的研究，检查高硝酸盐负荷的影响，并在饮用水处理场演示该技术，通过处理来自离子交换水处理系统的盐水再生流。这将扩大该技术的利用基础，并增加市场渗透率，因为该技术将补充现有的技术基础，并降低目前采用的去除NO3技术的运营成本。这将带来商业成功的高概率，加上一个大的销售基础，从而允许在补救市场上降低定价。在美国各地，有许多饮用水设施正在努力解决流入水流中溶解硝酸盐浓度过高的问题。目前的去除方法是通过反渗透或离子交换将NO3浓缩成小体积，然后适当地处理这种浓缩流。利用溶解的氢气作为电子供体，可以对废水中回收的NO3进行生物破坏。在反硝化过程中，氢与其他有机电子供体相比具有经济和操作上的优势。限制氢使用的因素是其溶解度低，即现有的商业气体溶解技术无法以安全、经济有效的方式溶解足够的氢。基于膜的气体溶解技术可以安全地为这些过程提供所需的氢气，但是市面上适用于无气泡气体溶解的膜性能较差，容易产生生物污染，或者两者兼而有之。Compact Membrane Systems, Inc.开发了一种用于微孔膜的高透气性全氟聚合物涂层。与微孔疏水膜相比，全氟聚合物涂层的光滑、无孔特性对生物污染具有很高的抵抗力。这种涂层可以消除性能、污染和成本障碍，这些障碍阻碍了膜基气体溶解技术在连续生物过程中的使用。第一阶段的研究确立了概念的可行性，并证明硝酸盐可以在不形成亚硝酸盐的连续模式下有效地修复。

This Small Business Innovation Research Phase II project will expand the Phase I study, examine the effect of high nitrate loading and demonstrate the technology at a drinking water treatment site, by treating the brine regenerant stream from an ion exchange water treatment system. This would broaden utilization base of the technology and allow increased market penetration since the technology will supplement the existing technology base and reduce the operating costs of the currently practiced technologies for NO3 removal. This will lead to both high probability of commercial success plus a large sales base to allow for lower pricing in remediation markets.Across the United States there are a number of drinking water facilities that are wrestling with the problem of high concentrations of dissolved nitrates in their influent water streams. The present methods of removal resort to concentrating the NO3 into a small volume by means of reverse osmosis or ion exchange and then disposing off this concentrated stream, appropriately. The recovered NO3 in such a waste stream can be destroyed biologically using dissolved hydrogen gas as the electron donor. Hydrogen offers several economic and operational advantages over other organic electron donors in denitrification. The factor limiting hydrogen use is its low solubility, i.e. existing commercial gas-dissolution technologies cannot dissolve sufficient hydrogen in a safe, cost effective manner. Membrane-based gas-dissolution technologies can potentially supply the hydrogen required for these processes safely, but commercially available membrane suitable for bubble-free gas-dissolution have poor performance, biological fouling, or both. Compact Membrane Systems, Inc., has developed a highly gas permeable perfluoropolymer coating for microporous membranes. The smooth, non-porous nature of the perfluoropolymer coating is highly resistant to biological fouling, especially compared to microporous hydrophobic membranes. This coating could remove the performance, fouling, and cost barriers that preclude the use of membrane-based gas dissolution technologies in continuous biological processes. The Phase I study established concept feasibility and demonstrated that nitrates could effectively remediate without the formation of nitrites in a continuous mode.