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

本研究的最终目标是开发一种工具，以预测通过膜去除致癌性、诱变性和致畸性消毒副产物的致病性病毒和前体，作为降低饮用水中微生物和化学物质风险的一步。提出的工作基于以下假设：1。天然有机物（NOM）的扩散受阻对其在纳滤膜上的运输有重要作用，导致氯化后有毒消毒副产物（DBPs）的形成。病原病毒的扩散在很大程度上有助于它们在微过滤器和超过滤器之间的运输，其对水化学、温度和孔径的依赖可以量化。直接测量膜孔径分布和膜中NOM和病毒的运输参数可以纳入理论模型，以预测它们的去除。尽管早期的研究已经对盐在反渗透中的扩散运输进行了研究，但这项研究将是第一次对NOM在纳滤膜上的扩散进行直接测量。转运的NOM， DBP前体和病毒跨膜将进行实验和理论研究。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进行阻碍传输的数值计算来解释。还将推导出普遍适用的模型（与使用的膜和水源位置无关），用于预测“前体有限”水域（低NOM含量）中三卤甲烷和卤乙酸的形成。

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.