CAREER: Membrane Processes for DBP Precursor Control: Effects of Colloid Stability and Membrane Surface Chemistry on Flux and Rejection

9984709 Kilduff在世界范围内，合成聚合物膜在水处理中的应用越来越多，特别是在去除消毒副产物（DBP）前体以及病原生物和病毒方面。微孔材料容易受到有机大分子和其他胶体的污染，这种污染往往控制着市政和工业应用中膜处理的效率、可靠性和成本。本研究的目标是：(1)了解膜过滤系统中有机大分子与其他天然有机和无机胶体之间的相互作用，以及胶体稳定性如何影响膜过程的性能；(2)了解膜通量和排斥与膜表面化学的关系，并确定紫外线光电化的效果，以生产更耐污染的过滤膜。将需要分馏和表征，以确定非均质环境胶体混合物组分的组成和反应性。混合物的分离将在大小的基础上进行，使用过滤和化学功能，使用吸附色谱和溶剂沉淀。将评估单个有机物分离物和胶体混合物对膜性能（污染、排斥和清洁）的影响。混合物将包括有机物组分和亚微米无机胶体（粘土、二氧化硅和氧化铁）。利用原子力和共聚焦显微镜，将污垢与胶体稳定性和污垢层形态有关。减轻污垢效应的策略将集中在调整表面化学以减少有机分子和胶体的结合。聚合物膜的表面将通过UV辐射进行修饰（使其更亲水），然后进行单体接枝和随后的聚合。评估单体类型、反应时间和紫外线辐射强度的影响。通过扫描电子显微镜、电子能谱、接触角、衰减全反射红外光谱、原子力显微镜和污染电位等方法对接收膜和污染膜进行表征。教育计划的中心是开发一门新的膜工艺课程，学生不仅要学习工艺基础知识，还要学习污垢如何导致处理系统表现出随时间变化的性能，以及如何将准确的参数估计纳入设计过程以提高工艺可靠性。＊＊＊

9984709 Kilduff The use of synthetic polymer membranes in water treatment is increasing worldwide, especially for the removal of disinfection by-product (DBP) precursors and of pathogenic organisms and viruses. The microporous materials are vulnerable to fouling by organic macromolecules and other colloids and this fouling often contols the efficiency, reliability and costs of membrane processes in municipal and industrial applications. The goals of this research are to: (1) understand the interactions between organic macromolecules and other natural organic and inorganic colloids in membrane filtration systems and how colloid stability influences the performance of membrane processes and (2) understand how membrane flux and rejection are related to membrane surface chemistry and identify the efficacy of UV photomodification to produce filtration membranes more resistant to fouling. Fractionation and characterization will be required to identify the composition and reactivity of components of heterogeneous environmental colloid mixtures. Separation of mixtures will be done on the basis of size, using filtration, and chemical functionality, using adsorption chromatography and solvent precipitation. The effects of individual organic matter isolates and of colloid mixtures on membrane performance (fouling, rejection and cleaning) will be evaluated. Mixtures will include organic matter fractions and sub-micron inorganic colloids (clays, silica and iron oxides). Fouling will be related to colloid stability and fouling layer morphology using atomic force and confocal microscopy. Strategies to mitigate fouling effects will focus on tailoring surface chemistry to reduce the binding of organic molecules and colloids. The surfaces of polymeric membranes will be modified (made more hydrophilic) by UV radiation followed by monomer grafting and subsequent polymerization. Effects of monomer type, reaction time and UV radiation intensity will be evaluated. As-received and fouled membranes will be characterized by scanning electron microscopy, electron spectroscopy, contact angle, attenuated total reflection infrared spectroscopy, atomic force microscopy and fouling potential in bench-scale test cells.The education plan centers around the development of a new Membrane Processes course from which students will learn not only process fundamentals but also how fouling can cause treatment systems to exhibit time-dependent performance, and how to incorporate accurate parameter estimation into the design process to improve process reliability. ***