Reactive Membrane Technology for Water Treatment

水处理反应膜技术

• 批准号: 0403581
• 负责人: Richard Lueptow
• 金额: --
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-11-15 至 2009-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0403581&HistoricalAwards=false
• 关键词: Reactive; Membrane; Technology; Water; Treatment

0403581LueptowIn response to both legislative and health related events, low-pressure membrane filtration (LPMF) is an emerging technology that is showing accelerated growth in the drinking water industry. There are a number of advantages to LPMF relative to conventional treatment such as superior treated water quality, little need for chemical additives, low energy requirements, and a compact, modular system. Yet, a major limitation associated with LPMF is its ineffectiveness in altering organic quality or quantity. Another problem common to all membrane systems, albeit in varying degrees, is fouling related to particle, organic, and microbial deposition at the membrane surface. We propose to create a novel reactive membrane system by coupling TiO2 photocatalysis and rotating ceramic membrane filtration. The principle of this process is that robust water treatment is achieved by integrating the physical separation of particles and chemical oxidation of organic and microbial constituents in combination with physical and chemical control of surface fouling. The proposed research is based on the activation of TiO2 nanoparticles by UV light to produce HO. and other reactive species (e.g., H2O2) at or near the rotating membrane surface. These highly oxidizing radials are also highly reactive with dissolved organic compounds and microorganisms so they will act to minimize biological and chemical fouling. Furthermore, the centrifugal instabilities and high shear created by the rotation of the cylindrical membrane significantly reduce concentration polarization and particle deposition at the membrane surface and also create optimal mass transfer conditions to promote high rates of photocatalytic reaction. The project involves three principal research tasks: 1) synthesis of reactive membranes and construction of prototype reactive rotating membrane systems; 2) characterization and selection of an optimum reactive membrane system for particle filtration, organic degradation, micropollutant destruction, microbial disinfection, and fouling control based on model water tests; and 3) testing reactive membrane performance using real waters, with special attention to determining how disinfection byproduct formation potential is modified by treatment. By rigorously comparing the performance of the reactive membrane prototypes to reference systems reflecting the individual action of either photocatalysis or rotating filtration, we will determine under what conditions the coupling of photocatalysis and membrane filtration causes a deterioration in intrinsic properties. In this way, we will also determine the synergistic interactions that result in high removals of particles and microorganisms, oxidative transformation of organic compounds, and effective control of surface fouling. Model water tests will be used to select a set of reactive membrane prototypes for testing with real surface waters. This research will have a profound impact on the growth of the low-pressure membrane industry and promote an expansion in its application beyond drinking water treatment to water reuse, advanced wastewater treatment, and industrial water processing. The advantages of the reactive membrane system over conventional membranes are reduced pre/post-treatment and cleaning requirements and greater production of higher quality filtrate. These advantages should offset any additional costs related to manufacturing and operating the system. The broader impact of this research is that it provides a technologically reliable way to use water having low organic and microbiological quality as a drinking water source, which is critical in many parts of the world and the U.S. where fresh water quality is seriously degraded. The research program integrates fluid mechanics, environmental chemistry, material synthesis, and photochemistry to provide a superb interdisciplinary research program for two doctoral candidates.

作为对立法和健康相关事件的回应，低压膜过滤(LPMF)是一项新兴技术，在饮用水行业显示出加速增长的趋势。与常规处理相比，LPMF具有许多优点，如处理后的水质优良，几乎不需要化学添加剂，能耗低，系统紧凑，模块化。然而，与LPMF相关的一个主要限制是它在改变有机质量或数量方面的无效。所有膜系统的另一个共同问题是与膜表面的颗粒、有机和微生物沉积有关的污染，尽管程度不同。我们提出通过将TiO2光催化和旋转陶瓷膜过滤相结合来创建一种新型的反应膜体系。该工艺的原理是，通过将颗粒的物理分离、有机和微生物成分的化学氧化与表面污垢的物理和化学控制相结合，实现坚固的水处理。拟议的研究是基于紫外光激活纳米二氧化钛产生HO。以及在旋转膜表面或其附近的其他活性物种(例如，过氧化氢)。这些高度氧化的放射物也与溶解的有机化合物和微生物高度反应，因此它们将采取行动，最大限度地减少生物和化学污染。此外，圆柱膜的旋转产生的离心不稳定性和高剪切显著地减少了浓差极化和膜表面的颗粒沉积，并创造了最佳的传质条件以促进高速率的光催化反应。该项目涉及三项主要研究任务：1)反应膜的合成和反应旋转膜系统原型的构建；2)基于模型水试验，表征和选择用于颗粒过滤、有机降解、微污染物破坏、微生物消毒和污染控制的最佳反应膜系统；3)使用真实水测试反应膜的性能，特别注意确定处理如何改变消毒副产物的形成潜力。通过将反应膜原型的性能与反映光催化或旋转过滤单独作用的参比系统进行严格的比较，我们将确定在什么条件下光催化和膜过滤的耦合会导致固有性能的恶化。通过这种方式，我们还将确定导致颗粒和微生物的高去除、有机化合物的氧化转化和有效控制表面污垢的协同作用。模型水试验将被用来选择一套反应性膜原型，用于用真实的地表水进行测试。这项研究将对低压膜行业的发展产生深远的影响，并推动其应用范围从饮用水处理扩大到水回用、深度废水处理和工业水处理。与传统膜相比，反应膜系统的优点是减少了前/后处理和清洗要求，并产生了更高质量的滤液。这些优势应该会抵消与制造和运营该系统相关的任何额外成本。这项研究的更广泛影响是，它提供了一种在技术上可靠的方式，将有机和微生物质量较低的水用作饮用水水源，这在世界许多地区和淡水质量严重恶化的美国至关重要。该研究计划整合了流体力学、环境化学、材料合成和光化学，为两名博士生提供了一流的跨学科研究计划。