A Novel Nanocomposite Photocatalyst for Water Treatment

描述（由申请人提供）：安全饮用水的供应是一个重要的健康问题。将水氯化作为一种标准的水处理方法，大大减少了水传播疾病的数量。然而，消毒副产物（DBPs）是由氯与溶解在水中的天然有机物（NOM）、溴化物和碘化物之间的反应形成的。长期接触dbp会增加患癌症和其他不良健康影响的风险。因此，美国环境保护署（EPA）对饮用水中的某些dbp实施了严格的限制。替代消毒剂的使用越来越受欢迎，因为它们降低了受管制dbp的水平。然而，它们会形成高水平的新dbp和/或不受调控的dbp，其中一些dbp比受调控的dbp更具细胞毒性和基因毒性。类似的情况也发生在饮用水公用事业公司利用受废水污染的水源来满足人口增长对饮用水的需求时。饮用水消毒的这些变化正在产生大量新出现的高毒性dbp，引起人们的关注，因为EPA监管的dbp不一定是毒性最大或最常见的dbp。水厂在消毒前减少水源水中NOM的方法在技术上是不合理的，因为它需要一个新的水处理厂，建设和运营成本都很高。因此，迫切需要在饮用水使用点（POU）消除dbp的新方法。在目前的第二期拨款期间，正在开发一种新的光催化氧化系统，用于污水处理厂的水处理。目的是提供一种独特的、安全的、低成本的消费设备，旨在有效地消除水消耗位置的dbp和微生物。我们的光催化系统已经成功地处理了含有调控DBPs的水样。此外，该POU系统通过降解低于EPA水平的微生物和DBPs，大大改善了饮用水质量。为了解决与新兴dbp相关的日益增加的关注，我们请求为本次修订申请提供资金，以扩大当前II期拨款的具体目标、研究设计和方法的范围，通过使用Lynntech的光催化系统对有毒、不受管制的新兴dbp进行破坏研究。如果我们的产品取得成功，我们不仅将有助于解决严重的健康威胁（通过使dbp无害（不依赖于水处理厂使用的消毒剂）和提供安全、清洁的饮用水），而且还将有助于美国经济：通过获得扩大当前赠款目标所必需的美国技术，以及通过雇用、培训和支持人员开展工作以实现修订应用程序的目标。此外，Lynntech的产品将销售到美国的医院和学校，并通过正常的商业化渠道销售到美国家庭。

DESCRIPTION (provided by applicant): The availability of safe drinking water is an important health concern. The introduction of water chlorination as a standard water treatment has resulted in a significant decrease in the number of waterborne diseases. However disinfection byproducts (DBPs) are formed by the reactions between chlorine and the natural organic matter (NOM), bromide, and iodide dissolved in water. Long-term exposure to DBPs increases the risk of cancer and other adverse health effect. As a consequence, the U.S. Environmental Protection Agency (EPA) has implemented stringent limits for some DBPs in drinking water. The use of alternative disinfectants is gaining popularity since they lower the levels of regulated DBPs. However, they form high levels of new and/or unregulated DBPs, some of which are more cytotoxic and genotoxic than regulated DBPs. Similar situation occurs when drinking water utilities exploit the use of source waters impaired by wastewater effluents beyond pristine water supplies to accommodate drinking water needs of population growth. These changes to drinking water disinfection are creating a host of emerging, highly toxic DBPs, raising concern because EPA's regulated DBPs are not necessarily the most toxic or common DBPs. And water plant approaches to reduce NOM in source water prior to disinfection are not technically sound because it requires a new water treatment plant that is costly to construct and operate. Thus, new methods to eliminate DBPs in drinking water at the point-of-use (POU) are strongly needed. During the current Phase II grant, a new photocatalytic oxidation system for POU water treatment is being developed. The aim is to provide a unique, safe, low-cost consumer device designed to effectively eliminate DBPs and microorganisms at the location where water is consumed. Our photocatalytic system has successfully treated water samples containing regulated DBPs. In addition, this POU system considerably improves drinking water quality by degrading both microorganisms and DBPs well bellow EPA levels. To address raising concern related to emerging DBPs, we request funding for this Revision Application to expand the scope of the specific aims, research design, and methods of the current Phase II grant by carrying out studies in the destruction of toxic, unregulated, emerging DBPs using Lynntech's photocatalytic system. If our product is successful, we will contribute not only to solve a serious health threat (by rendering DBPs harmless (independent of the disinfecting agent used by the water treatment plant) and providing safe, clean drinking water), but also by helping the American economy: by acquiring Amercican technology essential to expand the goals of the current grant and by hiring, training, and supporting personnel to carry out work to accomplish the Revision Application goals. In addition, Lynntech's product will be sold to American hospitals and schools, and through normal channels of commercialization, it will be sold to American households. PUBLIC HEALTH RELEVANCE: While it is vitally important to disinfect drinking water, as thousands of people died from waterborne illnesses before disinfection practices were started in the early 1900s, it is also important to minimize the exposure to disinfection byproducts (DBPs), which are formed by the reactions between the disinfecting agent and the natural organic matter (NOM), bromide, and iodide dissolved in water. Long-term exposure to DBPs increases the risk of cancer and other adverse health effect. The goal of this Competitive Revision Application is to support the expansion of the Phase II scope (that demonstrated Lynntech's POU photocatalytic system successful destruction of regulated DBPs) by demonstrating the effective destruction of toxic, emerging, unregulated DBPs, some of which are more cytotoxic and genotoxic than EPA's regulated DBPs.