RII Track-4: NSF: Understanding Wildfire Risks to Drinking Water Source Waters: Pyrogenic Changes to Organic Matter and Disinfection By-product Formation

RII Track-4：NSF：了解饮用水源水域的野火风险：有机物的热原变化和消毒副产品的形成

• 批准号: 2229313
• 负责人: David Hanigan
• 金额: $ 24.77万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2229313&HistoricalAwards=false
• 关键词: RII; Track; NSF; Understanding; Wildfire

Wildfires are growing in size, severity, and frequency due to drought, forest management, and climate change. Wildfire mobilizes soil organic matter through partial combustion. This partially combusted organic matter is then transported after precipitation events to downstream drinking water treatment plants. Disinfection is a key component of drinking water treatment and inactivates pathogens. However, the chemicals used for disinfection also react with the diverse organic compounds present in all water sources. Some of these reactions result in the production of carcinogenic disinfection by-products, which have regulatory limits in finished drinking water set by the U.S. Environmental Protection Agency. There is currently conflicting evidence of whether partially combusted soil organic matter causes more or fewer disinfection by-products to form than would otherwise, leaving uncertainty about the future security of water supplies in wildfire-prone regions. The overarching goal of this research is to understand how fire severity affects the formation of disinfection by-products at downstream drinking water treatment plants. To achieve this goal, the PI and a graduate student will travel to and conduct experiments at the University of Colorado-Boulder in collaboration with wildfire and organic matter experts currently serving as faculty.This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows (RII Track-4:NSF) project will provide a fellowship to an Assistant Professor and training for a graduate student at the University of Nevada Reno. This work would be conducted in collaboration with researchers at the University of Colorado-Boulder. The PI and one graduate student will 1) learn new organic matter characterization methods from experts in the field and apply them to Caldor Fire samples collected near the PI’s home institution, and 2) apply the learned skills to samples produced under highly controlled laboratory conditions. Success of the two aims will prove or disprove the overall hypothesis, that moderate wildfire severity results in the greatest production of disinfection by-product precursors, which are destroyed at higher temperatures (e.g., above 350°C). The rationale for the proposed research is that disinfection by-products are hazardous to human health, and mitigating exposure (i.e., meeting regulatory standards) is challenging for drinking water utilities without an understanding of how specific fire conditions affect pyrogenic organic matter mobilization and reactivity. The findings will advance the fundamental knowledge of wildfire impacts on organic matter contained in drinking water source catchments, which is somewhat well understood in terms of material transport, but not well understood in terms of potential oxidation chemistry involving disinfectants and transport of small, drinking-water-regulated, pyrogenic molecules. The findings will also inform scientists, regulators, and local utilities of the potential for regulatory exceedances during and after wildfire events. The collaborative research will ultimately improve the research capacity of the home institution and benefit the State of Nevada, which is the driest state in the nation and subject to both water scarcity and wildfire. A graduate student will also benefit through exposure to subject matter experts, improving their technical and communication skills, and providing networking opportunities. One to two undergraduate students will gain experience in sampling remote areas.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.

由于干旱，森林管理和气候变化，野火的规模，严重程度和频率正在增长。野火通过部分混合物动员土壤有机物。然后在降水事件后将部分燃烧的有机物运输到下游饮用水处理厂。消毒是饮用水处理的关键组成部分，并使病原体失活。但是，用于消毒的化学物质也与所有水源中存在的各种有机化合物反应。其中一些反应导致了致癌消毒副产品的产生，这些副产品在美国环境保护局设定的饮用水中具有监管限制。目前有相互矛盾的证据表明，部分燃烧的土壤有机物是否会导致更多或更少的消毒副产品形成，而不是在其他情况下形成，这使人们对野火易发的地区的供水安全造成了不确定性。这项研究的总体目标是了解火力严重程度如何影响下游饮用水处理厂的消毒副产品的形成。为了实现这一目标，PI和研究生将与目前担任教职员工的Wildfire和有机物专家合作，在科罗拉多大学 - 博尔德大学进行实验。这项研究基础赛道基础-4 EPSCOR研究Fellows（RII Track-4：NSF）项目将为助理教授和研究生提供研究生的研究。这项工作将与科罗拉多大学博尔德大学的研究人员合作进行。 PI和一名研究生将从该领域的专家学习新的有机物表征方法，并将其应用于PI家居附近收集的Caldor消防样本，以及2）将学习的技能应用于在高度控制的实验室条件下生产的样品。这两个目标的成功将证明或反驳总体假设，即现代化的野火严重性导致消毒副产物前体的最大产生，这些副产物前体在较高的温度下（例如350°C以上）被破坏。拟议的研究的理由是，消毒副产品对人类健康有害，缓解暴露（即满足监管标准）对饮用水公用事业构成了挑战，而又不了解特定的火灾状况如何影响热源有机物的动员和反应。这些发现将促进野火对饮用水源流域中包含的有机物的影响的基本知识，这是从材料运输方面得到充分理解的，但就潜在的氧化化学涉及消毒剂和小型饮酒 - 饮酒 - 饮用水调节的，受饮酒 - 受饮酒 - 受到的毒性分子的运输而言，这一点尚未得到充分理解。这些发现还将在野火事件期间和之后向科学家，监管机构和当地公用事业提供可能超出监管的可能性。合作研究最终将提高家庭机构的研究能力，并使内华达州受益，内华达州是全国最干燥的状态，既遭受水的稀缺和野火。研究生还将通过接触主题专家，提高其技术和沟通技巧并提供网络机会来受益。一到两个本科生将获得取样偏远地区的经验。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来评估被认为是宝贵的支持。

项目成果

Wildfire impact on disinfection byproduct precursor loading in mountain streams and rivers

野火对山间溪流和河流中消毒副产物前体负荷的影响

• DOI: 10.1016/j.watres.2023.120474
• 发表时间: 2023
• 期刊: Water Research
• 影响因子: 12.8
• 作者: Hickenbottom, Kenneth;Pagilla, Krishna;Hanigan, David
• 通讯作者: Hanigan, David

Reduction of haloacetonitrile-associated risk by adjustment of distribution system pH

通过调整分配系统 pH 值降低卤代乙腈相关风险

• DOI: 10.1039/d3ew00230f
• 发表时间: 2023
• 期刊: Environmental Science: Water Research & Technology
• 作者: Stewart, Kevin;An, Dong;Hanigan, David
• 通讯作者: Hanigan, David