Collaborative Research: Shape Effects on Microorganism Removal by Microfiltration and Ultrafiltration Membranes

合作研究：形状对微滤和超滤膜去除微生物的影响

• 批准号: 0966934
• 负责人: Ruth Baltus
• 金额: $ 14.77万
• 依托单位: Clarkson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0966934&HistoricalAwards=false
• 关键词: Collaborative; Research; Shape; Effects; Microorganism

This NSF award by the Chemical and Biological Separations program supports work to examine from both experimental and theoretical viewpoints the effect of microorganism size and shape on membrane rejection. Microfiltration and ultrafiltration membranes are increasingly employed in the food processing, biotechnology, pharmaceutical industries and for environmental separations. These advanced filtration techniques have gained popularity in municipal water and wastewater treatment particularly following the 1993 Cryptosporidium outbreak in Milwaukee, WI. This is the single largest waterborne disease outbreak in the history of the United States resulting in over 400,000 becoming ill and 50 deaths. Even though membranes present a virtually complete barrier to this parasite (conventional filtration techniques do not), viruses and bacteria can pass through them potentially posing human health risks. MF and UF systems are also employed during purification and manufacturing of drugs, juices, milk and other products where sterility is an important consideration.Paradoxically, even though microfiltration and ultrafiltration systems do not generally achieve complete virus and bacteria removal, the factors governing microorganism transport across them are not well understood, particularly for non-spherical organisms. This necessitates conservative membrane design and implementation. Further, previous experimental and theoretical studies of colloid passage across membranes have focused predominantly on spherical particles even though rod-shaped bacteria and non-spherical viruses are frequently encountered in water supplies.In this work comprehensive theoretical and experimental investigations will be performed to delineate hindered transport phenomena contributing to the removal of viruses and bacteria by microfiltration and ultrafiltration membranes. The focus will be on systematically and rigorously determining the influence of microorganism aspect ratio and the importance of axial and rotational Peclet numbers on transport. The filtration of numerous rod-shaped viruses and bacteria across a range of pore sizes and transmembrane pressures will be examined using both track-etched membranes with an idealized pore geometry as well as commercially relevant phase inversion membranes which have a complex porous structure. A rigorous model that incorporates Brownian diffusion and particle alignment with the flow will be developed.Broader impacts of the work lie in (i) training a high school science/math teacher in Clarkson and another at Houston, (ii) communications with industrial scientists at Millipore Corporation, (iii) training students to perform interdisciplinary and collaborative research applying principles from transport phenomena, biotechnology, and environmental engineering, (iv) supporting undergraduates to conduct research through course projects and summer research, and (v) disseminating research results in peer-reviewed publications and conference presentations. We hope to draw participants from a variety of K-12 institutions across Houston and Potsdam, particularly those with historically minority student bodies in several of these activities.

化学和生物分离计划的NSF奖项支持从实验和理论角度研究微生物大小和形状对膜截留率的影响。微滤膜和超滤膜越来越多地用于食品加工、生物技术、制药工业和环境分离。这些先进的过滤技术在市政水和废水处理中得到普及，特别是在1993年威斯康星州密尔沃基的隐孢子虫爆发之后。这是美国历史上最大的一次水传播疾病爆发，导致40多万人患病，50人死亡。尽管膜对这种寄生虫提供了几乎完全的屏障（传统的过滤技术没有），但病毒和细菌可以通过它们，潜在地对人类健康构成风险。MF和UF系统也用于药物、果汁、牛奶和其他产品的纯化和生产，其中无菌性是一个重要的考虑因素。特别是，即使微滤和超滤系统通常不能实现完全的病毒和细菌去除，但控制微生物穿过它们的因素还不清楚，特别是对于非球形生物。这需要保守的膜设计和实施。此外，以前的实验和理论研究胶体通过膜主要集中在球形颗粒，即使棒状细菌和非球形病毒是经常遇到的供水。在这项工作中，将进行全面的理论和实验研究，以描绘阻碍运输现象有助于去除病毒和细菌的微滤和超滤膜。重点将是系统和严格地确定微生物的纵横比的影响和轴向和旋转Peclet数对运输的重要性。将使用具有理想化孔几何形状的径迹蚀刻膜以及具有复杂多孔结构的商业相关相转化膜来检查多种杆状病毒和细菌在一系列孔径和跨膜压力下的过滤。一个严格的模型，结合布朗扩散和粒子排列的流动将被开发。更广泛的影响的工作在于（i）培训高中科学/数学教师在克拉克森和另一个在休斯顿，（ii）通信与工业科学家在密理博公司，（iii）培训学生进行跨学科和合作研究应用原则，从运输现象，生物技术，（iv）支持本科生通过课程项目和暑期研究进行研究，以及（v）在同行评审的出版物和会议报告中传播研究成果。我们希望吸引来自休斯顿和波茨坦的各种K-12机构的参与者，特别是那些在其中几项活动中历史上有少数民族学生的机构。