UV-based and Ion Exchange Technologies for Drinking Water Treatment Applications

天然有机物质（NOM）和硝酸盐是地表水中引起关注并影响处理过程的成分。NOM是氯化消毒副产物的主要前体。此外，它还会造成膜污染，降低水的美观性，导致水的生物稳定性恶化。在基于紫外线（UV）的高级氧化工艺（AOPs）用于地表水去除微污染物的过程中，NOM清除羟基自由基并屏蔽紫外线，从而降低了所应用处理的整体效果。原水中的硝酸盐是一种阴离子，如果超过规定，就会引起健康问题。此外，在某些uv基AOPs的应用过程中，硝酸盐可以转化为亚硝酸盐（更严重的健康问题）。因此，改善基于uv的AOPs上游的水质是人们感兴趣的，并可能导致性能的提高和能耗的降低。******离子交换（IEX）处理工艺可以作为处理流程中的主要屏障，同时去除NOM和硝酸盐。IEX的应用有可能改善水质，经过进一步处理的AOPs用于去除微量浓度的微污染物。也就是说，研究表明，无机阴离子的存在会干扰NOM的去除，从而降低了IEX过程的总体效果。******拟议研究计划的主要目标是开发和解决将IEX和基于uv的AOPs应用于水处理的基本挑战。将特别强调开发和评价流化床IEX反应器及其与uv基AOPs的组合。此外，本提案旨在解决与IEX和基于uv的AOPs对水质影响有关的一些基础和工程问题。这些总体目标将通过关注三个具体和非常重要的子目标来实现：开发和研究流化床IEX工艺，并评估各种设计标准***2。通过改善上游水质，考察IEX工艺对uv基AOPs去除模型微污染物效果的影响***3。研究了IEX和UV-AOPs组合的整个水质剖面。研究了IEX和UV-AOP联合处理过程中含氮副产物的命运。******以上每个子目标都将通过广泛的实验室实验以及建模和理论分析来实现。所有这些都将导致有效技术的发展，将大大有助于改善加拿大的健康、生活质量和环境。它将对工程界和科学界产生有益的影响，因为它代表了开发和应用这种综合技术的基本途径

Natural organic matter (NOM) and nitrate are among the constituents of surface water causing concern and affecting treatment processes. NOM is known as a primary precursor for chlorinated disinfection by-products. Also, it causes membrane fouling, reduces the aesthetic quality of water, and leads to deterioration of biological stability of water. Under the application of ultraviolet (UV)-based advanced oxidation processes (AOPs) to surface water for the removal of micropollutants, NOM scavenges hydroxyl radicals and screens UV, thereby reduces the overall efficacy of the treatment applied. Nitrate in raw water is an anion of health concern if it exceeds the regulations. Moreover, nitrate can be converted to nitrite (a more serious health concern) during the application of certain UV-based AOPs. Therefore, improving the water quality upstream of the UV-based AOPs is of interest and could lead to improved performance and reduced energy consumption.******Ion Exchange (IEX) treatment process could be utilized as the primary barrier in a treatment train to remove NOM and nitrate simultaneously. The application of IEX has the potential to improve water quality undergoing further treatment with AOPs used for the removal of trace concentration of micropollutants. That said, studies have shown the presence of inorganic anions to interfere with NOM removal, thus reducing the overall efficacy of the IEX process.******The main objective of the proposed research program is to develop and address fundamental challenges of applying IEX as well as UV-based AOPs to water treatment. Special emphasis will be given to developing and evaluating fluidized bed IEX reactors along with their combinations with UV-based AOPs. In addition, this proposal intends to address some fundamental and engineering issues related to the impact of IEX and UV-based AOPs on water quality. These overall goals will be achieved by focusing on three specific and highly important sub-objectives:***1. Develop and study fluidized bed IEX process and evaluate various design criteria***2. Investigate the impact of IEX process on the efficacy of UV-based AOPs at removing model micropollutants by improving the upstream water quality***3. Study the profile of water quality throughout the combined IEX and UV-AOPs ***4. Study the fate of nitrogenated byproducts during the combined IEX and UV-AOP treatments.******Each of the above sub-objectives will be achieved through extensive laboratory experiments along with modeling and theoretical analysis. All these will lead to the development of efficient technologies will contribute significantly to improving health, quality of life, and the environment in Canada. It will have beneficial impacts among the engineering and scientific communities, since it represents a fundamental approach to the development and application of such integrated technology.**