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.

在水处理过程中使用消毒剂可以有效消除水传播疾病，但这些消毒剂会形成低浓度的致癌化学副产品。这些副产物往往在消毒废水中形成较高水平，这种复杂情况通常会随着河流、湖泊和含水层中这些致癌化学物质降解的时间而缓解。 然而，在饮用水回用场景中，降解时间会减少，从而使饮用水回用技术的未来面临风险。该项目将研究在饮用水回用废水深度处理过程中致癌化学物质 N-亚硝基二甲胺 (NDMA) 的形成机制和潜在解决方案。该项目还将增加大学和初中学生的教育机会，并通过两个工业合作伙伴和一所大学之间的合作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，这是一项可以支持我国水安全的宝贵技术。 N-亚硝基二甲胺 (NDMA) 是一种致癌化合物，在氯胺消毒过程中形成。进入饮用水处理厂的 NDMA 前体被认为源自废水。根据正在进行的 NDMA 前体研究，饮用水再利用系统中使用的一些技术已被确定为可减少 NDMA 出现和形成的技术：反渗透 (RO)（物理去除前体）和强紫外线 (UV)（将 NDMA 光解为亚硝酸盐）和二甲胺。虽然这些系统有效地将 NDMA 形成减少了 90%，但消毒水中的 NDMA 形成仍以生理相关浓度 (5 ng/L) 发生。这些前体的来源尚不清楚，但初步研究表明，处理过程本身可能会向水中释放新的 NDMA 前体子集。这项研究的总体假设是：饮用水再利用的高级处理通过从 RO 中浸出 NDMA 前体和/或在紫外线、过氧化氢 (UV/过氧化物) 处理过程中将不反应的有机物转化为 NDMA 前体，从而为成品水提供 NDMA 前体。该研究的基本原理是 NDMA 具有高度致癌性，虽然 RO 和 UV/过氧化物去除了大多数 NDMA 前体，但它们也改变了水的化学性质，可能导致新的 NDMA 前体的出现。该假设将通过追求 4 个具体目标进行检验：1）确定已知前体和化学添加物在形成 NDMA 时的反应性； 2) 确定UV/过氧化物转化产物和将非反应性有机N“上转换”为反应性NDMA前体的动力学； 3）表征高级水处理过程中NDMA前体池的大量化学特性的变化； 4) 确定可最大限度减少试点规模 NDMA 形成的运营变化。这些目标将使用研究团队成员首创的新型质谱和分离技术进行研究。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。