Collaborative Research: Treatment of Cyanotoxins by UV/Chlorine: Optimizing Removal While Developing Strategies to Minimize Disinfection Byproducts and Toxicity

合作研究：紫外线/氯处理蓝藻毒素：优化去除同时制定尽量减少消毒副产物和毒性的策略

• 批准号: 2042035
• 负责人: Bryan Brooks
• 金额: $ 12万
• 依托单位: Baylor University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2042035&HistoricalAwards=false
• 关键词: Collaborative; Research; Treatment; Cyanotoxins; UV

Harmful algal blooms (HABs) occur when harmful algae grow out of control in surface water systems including lakes, rivers, and estuaries. This causes a large decrease in oxygen levels in the water and the release of toxic chemicals commonly referred to as cyanotoxins. These toxins can cause illness and death in fish, animals, and humans. HABs are increasing in frequency and severity throughout the world and are often triggered by excessive nutrients (phosphorus and nitrogen). In recent years, severe HABs have occurred in more than 20 states throughout the United States. However, traditional drinking water treatment processes (coagulation, flocculation, sedimentation, and chlorination) cannot fully remove cyanotoxins (to below the concentrations considered as toxic by federal and state agencies) especially during massive HAB events. The overarching goal of this collaborative research project is to evaluate and optimize the performance of a new water treatment process that combines UV light with chlorine (UV/chlorine) to break down cyanotoxins present in drinking water. The successful completion of this project will benefit society through the development of new fundamental knowledge that could lead to a new water treatment technology (UV/Chlorine) for the removal cyanotoxins to safe levels while minimizing the formation of toxic disinfection by-products (DBPs). Further benefits to society will be achieved through outreach and educational activities including 1) workshops and interactions with drinking water treatment professionals and relevant stakeholders, 2) course development, and 3) the mentoring of three doctoral students. Cyanotoxins, released by cyanobacteria during harmful algae blooms (HABs), are major threats to human and ecosystem health in the United Stated and worldwide. Various water treatment technologies, including sorption with granular activated carbon, membrane filtration, chlorination, ozonation, and advanced oxidation processes (AOPs), have shown potential to remove or degrade cyanotoxins. However, cellular lysis can occur during treatment thus increasing exposure to toxins from treated drinking water. In addition, toxic disinfection by-products (DBPs) might be generated when disinfectants such as chlorine react with cyanotoxins and/or algal/planktonic organic matter. Thus, a detailed and careful examination of cyanotoxin degradation during water treatment is critically needed to ensure safe drinking water for the public. The overarching goals of this project are to evaluate the performance of UV/chlorine treatment to degrade cyanotoxins in drinking water sources and elucidate the mechanisms of DBP formation and toxicity under relevant process and environmental conditions. To advance these goals, the collaborative research team proposes to 1) investigate the degradation of two common classes of cyanotoxins (microcystins and cylindrospermopsin) along with a group of 70 related DBPs (including regulated and priority unregulated DBPs); 2) evaluate the role of process conditions (i.e., radiation dose and wavelength, chlorine dose) and water quality parameters (algal organic matter, presence of halides, and solution pH) on degradation efficiency, and 3) determine the reaction kinetics, formation pathways of transformation products including DBPs, and their potential toxicity to human and ecosystems using transcriptomics. The successful completion of this project has potential for transformative impact through the development of new fundamental knowledge about the UV/Chlorine water treatment process that could lead to the effective removal cyanotoxins from drinking water sources to safe levels while minimizing the formation of toxic DBPs.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.

当湖泊、河流和河口等地表水系统中有害藻类生长失控时，就会发生有害藻华 (HAB)。这会导致水中的氧气含量大幅下降，并释放出通常被称为蓝藻毒素的有毒化学物质。这些毒素会导致鱼类、动物和人类患病和死亡。全世界范围内HAB的发生频率和严重程度都在增加，并且通常是由过量的营养物质（磷和氮）引发的。近年来，美国20多个州发生了严重的HAB。然而，传统的饮用水处理工艺（混凝、絮凝、沉淀和氯化）无法完全去除蓝藻毒素（低于联邦和州机构认为有毒的浓度），尤其是在大规模 HAB 事件期间。该合作研究项目的总体目标是评估和优化新型水处理工艺的性能，该工艺将紫外线与氯（UV/氯）相结合，分解饮用水中存在的蓝藻毒素。该项目的成功完成将通过开发新的基础知识造福社会，这些知识可能会产生新的水处理技术（紫外线/氯），将蓝藻毒素去除到安全水平，同时最大限度地减少有毒消毒副产物（DBP）的形成。将通过外展和教育活动实现进一步的社会效益，包括 1) 研讨会以及与饮用水处理专业人员和相关利益相关者的互动，2) 课程开发，以及 3) 对三名博士生的指导。 蓝藻在有害藻华 (HAB) 期间释放的蓝藻毒素是对美国和全世界人类和生态系统健康的主要威胁。各种水处理技术，包括颗粒活性炭吸附、膜过滤、氯化、臭氧化和高级氧化工艺 (AOP)，已显示出去除或降解蓝藻毒素的潜力。然而，在治疗过程中可能会发生细胞溶解，从而增加接触经过处理的饮用水中的毒素。此外，当氯等消毒剂与蓝藻毒素和/或藻类/浮游有机物发生反应时，可能会产生有毒消毒副产物（DBP）。因此，迫切需要对水处理过程中蓝藻毒素的降解进行详细而仔细的检查，以确保公众的安全饮用水。该项目的总体目标是评估紫外线/氯处理降解饮用水源中蓝藻毒素的性能，并阐明相关工艺和环境条件下 DBP 形成和毒性的机制。为了推进这些目标，合作研究团队建议 1) 研究两类常见的蓝藻毒素（微囊藻毒素和柱藻毒素）以及 70 种相关 DBP（包括受监管和优先不受监管的 DBP）的降解情况； 2) 评估工艺条件（即辐射剂量和波长、氯剂量）和水质参数（藻类有机物、卤化物的存在和溶液 pH 值）对降解效率的作用，以及 3) 使用转录组学确定反应动力学、包括 DBP 在内的转化产物的形成途径及其对人类和生态系统的潜在毒性。该项目的成功完成具有潜在的变革性影响，通过开发有关紫外线/氯水处理过程的新基础知识，可以有效地将饮用水源中的蓝藻毒素去除到安全水平，同时最大限度地减少有毒 DBP 的形成。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。