"Colloidal Fouling of Porous Membrane Filters: The Effect of Particle Size and Stability

本项目的目的是确定胶体颗粒大小和稳定性对水和废水处理过程中使用的膜性能的影响。虽然已经开发了单独处理传输机制的膜组件中的颗粒传输模型，还没有提出结合这些机制的模型，也没有对这些机制之间的相互作用进行实验评估，以产生胶体可能存在的条件的完整图景。降低跨膜的通量。我们将使用压力场-流动分馏技术研究平板膜组件中布朗扩散、剪切诱导和横向迁移引起的颗粒传输。通过这种方法，颗粒脉冲被引入到多孔通道的入口处。这种理想化的膜组件出口中的颗粒浓度响应使用紫外线吸光度随时间进行监测，并与电传感区和光子相关测量进行对照。颗粒在通道中的保留时间可以与假设单一反向传输模式计算的保留时间进行比较。颗粒大小和透过膜的渗透率会有所不同，以创造有利于通过这些机制进行传输的条件。电动相互作用对反向传输的影响将通过对带电粒子和未带电粒子进行相同的实验来评估。导致该奖项的提案是为了响应NSF 88-99研究启动奖而提交的。拟议的工作可能导致改进膜的工程设计和使用膜处理工业和市政废水的工艺。

The objective of this project is to determine the role of colloid particle size and stability on performance of membranes used in water and wastewater treatment process. While models for particle transport in membrane modules have been developed which treat transport mechanisms individually, no model has yet been proposed which combines these mechanisms nor has the interaction between these mechanisms been evaluated experimentally to produce an complete picture of the conditions under which colloids may reduce the flux across membranes. Particle transport by Brownian diffusion, shear-induced, and lateral migration in a flat plate membrane module will be studies using pressure field-flow fractionation techniques. By this method, a pulse of particles is introduced at the inlet to a porous channel. The particle concentration response in the outlet of this idealized membrane module is monitored over time using UV absorbance and checked against electrical sensing zone and photon correlation measurements. The retention time of particles in the channel can be compared with the retention time calculated assuming a single mode of back-transport. Particle size and permeation rate through the membrane will be varied to produce conditions that favor transport by each of these mechanisms. The effect of electrokinetic interactions on back-transport will be evaluated by performing identical experiments with charged and uncharged particles. The proposal leading to this award was submitted in response to NSF 88-99, Research Initiation Awards. The proposed work may lead to improvements in the Engineering design of membrane and process using membranes for treatment of water and wastewater used industrially and municipally.