Collaborative Research: Coupled effects of particle shape/flexibility and pore morphology on membrane rejection: theory and experiment

合作研究：颗粒形状/柔韧性和孔形态对膜排斥的耦合影响：理论与实验

• 批准号: 1605088
• 负责人: Shankar Chellam
• 金额: $ 16.02万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1605088&HistoricalAwards=false
• 关键词: Collaborative; Research; Coupled; effects; particle

Proposal Numbers: 1604715 (Lead)/1605088 PIs: Baltus, R.E./Chellam, S.Collaborative Research: Coupled effects of particle shape/flexibility and pore morphology on membrane rejection: theory and experimentThe motivation for this research lies in the fact that by the year 2025, nearly 2 billion people are projected to live in areas of water scarcity. These drivers point to the need for advanced water and wastewater treatment technologies to alleviate ever-increasing water demand. Low-pressure liquid-solid membrane separation technologies such as microfiltration and ultrafiltration directly remove difficult-to disinfect parasites such as Giardia and Cryptosporidium, along with most bacteria, turbidity, and other colloidal materials. However, micro- and ultrafilters are not effective in removing viruses and some bacteria. The overall goal of this research is to examine the impact of non-ideal pore geometry and particle shape and flexibility on microbial rejection by porous membranes. This collaborative research project will perform both mathematical modeling and experimental work to quantitatively examine complex systems that more closely represent real-world separations. Results generated from this project will be important for the optimal design of micro- and ultrafiltration systems and for practical applications related to water and wastewater treatment and food, biotechnological, and pharmaceutical operations. Educational broader impacts include the development of science outreach activities geared towards elementary, middle, and high schools in neighboring communities in College Station, TX and Potsdam, NY to attract underrepresented minorities into STEM fields. Currently available membrane system design strategies are based on simple pore geometries and microbial shapes. Consequently, they cannot fully explain incomplete microbial removal observed in practice. This collaborative project will generate fundamental knowledge to characterize the hindered convection of tailed viruses, filamentous viruses, deformable bacteria, and rigid synthetic nanorods across porous membranes with tortuous interconnected pore networks. The project tightly integrates the experimental and theoretical efforts. The project will focus on separations of tailed and flexible viral and bacterial particles using low-pressure membranes with capillary pores as well as membrane systems with complex pore morphology. One example of the technological impact of this research is that it is addressing the difficulty in removing tailed viruses that are among the most abundant organisms in the environment and have been shown to penetrate so-called sterile filters. The research will examine whether flexible particles will be able to navigate around pore bends and whether bacteria that lack rigid cell walls can squeeze through pores. To theoretically examine particle shape and flexibility, detailed models of particle transport in a single cylindrical pore will be developed. Specifically, the physics of the non-spherical shape and flexibility of the viruses and bacteria will be incorporated. Experiments to validate these model predictions will be performed using track-etched membranes. To examine effects of membrane morphology including pore interconnectivity, 2D permeation measurements will be performed and interpreted using models developed to describe these systems. This project will generate a quantitative understanding of the role of complex pore geometries and microbial characteristics that govern rejection of microorganism from porous membranes. Incorporating such considerations will improve existing filtration models to more accurately describe rejection in real-world membrane separations.

项目项目号：1604715 (Lead)/1605088 PIs: Baltus， R.E./Chellam, s .合作研究：颗粒形状/柔韧性和孔隙形态对膜截流的耦合影响：理论与实验。本研究的动机在于，到2025年，预计将有近20亿人生活在缺水地区。这些驱动因素表明，需要先进的水和废水处理技术来缓解不断增长的用水需求。微滤和超滤等低压液固膜分离技术直接去除贾第鞭毛虫和隐孢子虫等难以消毒的寄生虫，以及大多数细菌、浊度和其他胶体物质。然而，微过滤器和超过滤器在去除病毒和某些细菌方面并不有效。本研究的总体目标是研究非理想孔隙几何形状和颗粒形状以及弹性对多孔膜微生物排斥的影响。这个合作研究项目将执行数学建模和实验工作，以定量地检查更接近代表现实世界分离的复杂系统。该项目产生的结果将对微滤和超滤系统的优化设计以及与水和废水处理、食品、生物技术和制药操作相关的实际应用具有重要意义。更广泛的教育影响包括发展面向德克萨斯州大学城和纽约州波茨坦邻近社区的小学、初中和高中的科学推广活动，以吸引代表性不足的少数民族进入STEM领域。目前可用的膜系统设计策略是基于简单的孔隙几何形状和微生物形状。因此，它们不能完全解释在实践中观察到的不完全的微生物去除。该合作项目将产生基础知识，以表征尾状病毒、丝状病毒、可变形细菌和刚性合成纳米棒在具有弯曲互连孔网络的多孔膜上的受阻对流。该项目将实验与理论紧密结合。该项目将专注于使用带有毛细管孔的低压膜以及具有复杂孔形态的膜系统分离尾部和柔性病毒和细菌颗粒。这项研究的技术影响的一个例子是，它解决了去除尾状病毒的困难，尾状病毒是环境中最丰富的生物体之一，已被证明可以穿透所谓的无菌过滤器。这项研究将检验柔性颗粒是否能够绕过孔隙弯曲，以及缺乏刚性细胞壁的细菌是否能够挤过孔隙。为了从理论上检验颗粒形状和柔韧性，将开发单个圆柱形孔隙中颗粒运输的详细模型。具体来说，将结合病毒和细菌的非球形和灵活性的物理特性。验证这些模型预测的实验将使用轨迹蚀刻膜进行。为了检查膜形态的影响，包括孔隙互连性，将进行二维渗透测量，并使用用于描述这些系统的模型进行解释。该项目将对复杂孔隙几何形状和微生物特性的作用产生定量的理解，这些特性控制着多孔膜对微生物的排斥。结合这些考虑将改进现有的过滤模型，以更准确地描述真实膜分离中的排斥。