CAREER: Disinfection Using Membranes: Optimizing Virus and Disinfection By-Product Control

这项研究的最终目标是开发工具，以预测通过膜对潜在致癌、致突变和致畸消毒产品的致病病毒和前体的去除，作为降低饮用水中微生物和化学风险的一步。建议的工作基于以下假设：1.天然有机物(NOM)的扩散受阻有助于其跨纳滤膜的传输，从而导致氯化时形成有毒的消毒副产物(DBPs)。致病病毒的扩散在很大程度上促进了它们在微滤器和超滤器之间的传输，其对水化学、温度和孔径大小的依赖可以被量化。NOM和病毒在膜中的膜孔径分布和传输参数的直接测量可以结合到理论模型中来预测它们的去除。尽管早期已经对盐在反渗透中的扩散传输进行了研究，但这项研究将是第一次直接测量NOM在纳滤膜上的扩散。NOM、DBP前体和病毒的跨膜传输将从实验和理论上进行研究。在不同的水化学条件下，这些污染物在膜上的对流和扩散的直接测量将通过对受阻传输进行数值计算来解释。还将推导出普遍适用的模型(与所用的膜和源水位置无关)，以预测“前体受限”(低NOM含量)水域中三卤代甲烷和卤代乙酸的形态。

0134301ChellamThe ultimate goal of this research is to develop tools to predict the removal of pathogenic viruses and precursors to potentially carcinogenic, mutagenic, and teratogenic disinfection by products by membranes as a step towards reducing microbial and chemical risks in drinking water. The proposed work is based on the following hypotheses:1. Hindered diffusion of natural organic matter (NOM) contributes significantly to its transport across nanofiltration membranes leading to formation of toxic disinfection by-products (DBPs) upon chlorination.2. Diffusion of pathogenic viruses contributes substantially to their transport across microfilters and ultrafilters and its dependence on water chemistry, temperature, and pore size can be quantified.3. Direct measurements of membrane pore size distributions and transport parameters of NOM and viruses in membranes can be incorporated into theoretical models to predict their removal.Even though early research had been conducted on diffusive transport of salts across reverse osmosis, this investigation will be the first to perform direct measurements of NOM diffusion across nanofiltration membranes. Transport of NOM, DBP precursors, and viruses across membranes will be investigated experimentally and theoretically. Direct measurements of convection and diffusion of these contaminants across membranes under varying water chemistry conditions will be interpreted by undertaking numerical calculations of hindered transport. Universally applicable models (independent of membrane used and source water location) to predict trihalomethane and haloacetic acid speciation in "precursor-limited" waters (low NOM content) will also be derived.