Mechanisms of Concentration Polarization and Cake Formation in Crossflow Membrane Filtration of Aqueous Colloidal Particles

水性胶体颗粒错流膜过滤中浓度极化和滤饼形成机制

• 批准号: 0114527
• 负责人: Menachem Elimelech
• 金额: $ 27.47万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-15 至 2004-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0114527&HistoricalAwards=false
• 关键词: Mechanisms; Concentration; Polarization; Cake; Formation

0114527 Elimelech The objective of this research is to provide a comprehensive microscopic-level understanding of the thermodynamics and micro-hydrodynamics of concentration polarization and cake formation in crossflow membrane filtration. A major emphasis will be placed on the identification of the transition point from a disordered liquid-like phase in the concentration polarization layer to an ordered solid-like cake layer. The research will involve the following tasks: 1) Prediction of the equilibrium structure of a colloidal dispersion, 2) Evaluation of the osmotic pressure, sedimentation coefficient and diffusion coefficient, 3) Prediction of the liquid-solid transition point in colloidal systems under crossflow membrane filtration conditions, 4) Prediction of the extent of concentration polarization and/or cake formation and the resulting permeate flux decline behavior, 5) Selection of a model experimental system for validation of the theory and 6) Experimental validation of the above theoretical approach using model colloidal dispersions at various background electrolyte concentrations, particle concentrations, pH, crossflow velocities and operating pressures. This research is expected to lead to a sound theoretical basis for quantification of permeate flux decline behavior in crossflow membrane filtration of colloidal dispersions. These results will become increasingly important as membrane processes, particularly nanofiltration and ultrafiltration, become more viable for treatment of natural and waste waters because these technologies offer a comprehensive approach to meeting multiple water quality objectives for a myriad of dissolved and colloidal contaminants. ***

0114527消除这项研究的目的是提供对浓度极化和跨流膜过滤中浓度极化和蛋糕形成的热力学和微动力学的全面理解。 将重点放在从浓度极化层中液体样相位到有序的固体样蛋糕层的过渡点的鉴定。该研究将涉及以下任务：1）预测胶体分散的平衡结构，2）评估渗透压，沉降系数和扩散系数，3）液体固相物过渡点在胶体过渡系统中预测跨流膜过渡条件下的液体固体过渡点的预测，或者允许浓度范围的行为和/////或/或/或/或）。一个模型实验系统，用于验证理论和6）在各种背景电解质浓度，颗粒浓度，pH，跨流速和操作压力下使用模型胶体分散的上述理论方法的实验验证。预计这项研究将导致一个合理的理论基础，以量化胶体分散体的跨流膜过滤中的渗透渗透率下降行为。 随着膜过程，尤其是纳米过滤和超滤，这些结果将变得越来越重要，因为这些技术提供了一种全面的方法来治疗天然和废水，以实现多种溶解和胶体污染物的多种水质目标。 ***