Collaborative Research: GOALI: WRF: Securing the Future of Direct and Indirect Potable Reuse ? N-nitrosodimethylamine (NDMA) Formation Pathways and Precursors

合作研究：GOALI：WRF：确保直接和间接饮用水再利用的未来？

• 批准号: 1803955
• 负责人: Megan Plumlee
• 金额: $ 7万
• 依托单位: Orange County Water District
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-15 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1803955&HistoricalAwards=false
• 关键词: Collaborative; Research; GOALI; WRF; Securing

The use of disinfectants during water treatment has effectively eradicated waterborne illness, but these disinfectants form low concentrations of carcinogenic chemical by-products. These by-products tend to form at higher levels in disinfected wastewater, a complication that is usually alleviated by time in rivers, lakes, and aquifers that allows for the degradation of these carcinogenic chemicals. However, this time for degradation is reduced in potable water reuse scenarios, putting the future of potable water reuse technologies at risk. This project will investigate the mechanisms of and potential solutions to the formation of a carcinogenic chemical, N-nitrosodimethylamine (NDMA), during advanced treatment of wastewater targeted for potable reuse. The project will also enhance educational opportunities for students at the college and middle school level, and provide new educational and research infrastructure in a partnership between two industrial partners and a university. If successful, this research can further enable the use of potable water reuse, a valuable technology that could support our nation's water security. N-nitrosodimethylamine (NDMA) is a carcinogenic compound that forms during chloramine disinfection. NDMA precursors that enter drinking water treatment plants are thought to originate in wastewater. Based on ongoing NDMA precursor research, some technologies used in potable reuse systems have been identified as technologies that reduce NDMA occurrence and formation: reverse osmosis (RO), which physically removes precursors, and strong ultraviolet (UV) light, which photolyzes NDMA to nitrite and dimethylamine. While these systems effectively reduce NDMA formation by 90%, NDMA formation still occurs at physiologically relevant concentrations (5 ng/L) in the disinfected water. The sources of these precursors are unknown, but preliminary research indicated that the treatment processes themselves may release a new subset of NDMA precursors into the water. The overarching hypothesis of this research is: Advanced treatment for potable reuse contributes NDMA precursors to the finished water via leaching NDMA precursors from RO and/or transforming unreactive organic matter to NDMA precursors during UV, hydrogen peroxide (UV/peroxide) treatment. The rationale that underlies the research is that NDMA is highly carcinogenic, and while RO and UV/peroxide remove most NDMA precursors, they also change the water chemistry which may cause occurrence of new NDMA precursors. The hypothesis will be tested by pursuing 4 specific aims: 1) Determine the reactivity of known precursors and chemical additions in forming NDMA; 2) Identify UV/peroxide transformation products and kinetics that "up-convert" unreactive organic N to reactive, NDMA precursors; 3) Characterize changes in bulk chemical characteristics of the NDMA precursor pool during advanced water treatment; and 4) Identify operational changes that minimize NDMA formation at pilot-scale. These aims will be investigated using novel mass spectrometric and separations techniques pioneered by members of the research team.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

水处理期间使用消毒剂有效地消除了水传播疾病，但这些消毒剂形成了低浓度的致癌化学副产品。这些副产品倾向于在消毒的废水中以较高的水平形成，这种并发症通常由河流，湖泊和含水层中的时间来缓解，允许这些致癌化学物质降解。 但是，这次降解在饮用水再利用情景中减少，使饮用水再利用技术的未来处于危险之中。该项目将研究在高级处理剂量饮用的废水中，调查了致癌化学化学，N-硝基二甲胺（NDMA）的机制和潜在解决方案。该项目还将为学院和中学阶段的学生提供教育机会，并在两个工业伙伴和一所大学之间的合作伙伴关系中提供新的教育和研究基础设施。如果成功，这项研究可以进一步实现饮用水再利用，这是一种可以支持我们国家水安全的宝贵技术。 N-硝基二甲胺（NDMA）是一种在氯胺消毒过程中形成的致癌化合物。进入饮用水处理厂的NDMA前体被认为起源于废水。基于正在进行的NDMA前体研究，在饮用的重复使用系统中使用的一些技术被确定为减少NDMA的发生和形成的技术：反渗透（RO），可以物理去除前体和强紫外线（UV）光，从而将NDMA转化为NDMA至硝酸盐和Dimethylamine。尽管这些系统有效地将NDMA的形成降低了90％，但在消毒的水中，NDMA的形成仍然存在于生理相关的浓度（5 ng/L）。这些前体的来源尚不清楚，但是初步研究表明，治疗过程本身可能会将新的NDMA前体子集释放到水中。这项研究的总体假设是：饮用可再利用的高级治疗方法通过将NDMA前体从RO和/或转化为/或将不反应性有机物转化为NDMA前体向NDMA前体促进NDMA前体，从而在UV，过氧化氢（UV/Peroxide）治疗过程中为NDMA前体转化为NDMA前体。研究基础的理由是NDMA具有高度致癌性，而RO和UV/UV/过氧化物消除了大多数NDMA前体，但它们也会改变水化学性质，这可能会导致新的NDMA前体发生。该假设将通过追求4个具体目的来检验：1）确定已知前体和化学添加的反应性； 2）确定“向上转化”无反应有机n的紫外/过氧化物转化产物和动力学，以反应性，NDMA前体； 3）表征晚期水处理期间NDMA前体池的散装化学特征的变化； 4）确定操作变化，以最大程度地减少试点尺度的NDMA形成。这些目标将使用研究小组成员开创的新型质谱和分离技术进行调查。该奖项反映了NSF的法定任务，并使用基金会的智力优点和更广泛的影响评估标准，认为值得通过评估来获得支持。