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.

当有害藻类在包括湖泊、河流和河口在内的地表水系统中生长失控时，就会发生有害藻华(HAB)。这会导致水中氧气水平的大幅下降和有毒化学物质的释放，这些化学物质通常被称为氰基毒素。这些毒素会导致鱼类、动物和人类的疾病和死亡。赤潮在世界各地的发生频率和严重程度都在增加，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赤潮。然而，传统的饮用水处理工艺(混凝、絮凝、沉淀和氯化)不能完全去除氰化毒素(降至联邦和州政府机构认为有毒的浓度以下)，特别是在大规模的HAB活动期间。这一合作研究项目的首要目标是评估和优化一种新的水处理工艺的性能，该工艺将紫外线与氯(UV/氯)相结合，以分解饮用水中存在的氰基毒素。该项目的成功完成将通过发展新的基础知识造福社会，这将导致一种新的水处理技术(紫外线/氯)，以将氰基毒素去除到安全水平，同时最大限度地减少有毒消毒副产品(DBPs)的形成。将通过外展和教育活动进一步造福社会，包括1)与饮用水处理专业人员和相关利益攸关方举办讲习班和互动，2)课程开发，3)指导三名博士生。蓝藻毒素是由蓝藻在有害藻华期间释放的一种毒素，在美国和世界范围内是对人类和生态系统健康的主要威胁。各种水处理技术，包括颗粒活性碳吸附、膜过滤、氯化、臭氧氧化和高级氧化工艺(AOPS)，已显示出去除或降解氰基毒素的潜力。然而，在治疗过程中可能会发生细胞溶解，从而增加对经处理的饮用水中毒素的暴露。此外，当氯等消毒剂与氰基毒素和/或藻类/浮游有机物反应时，可能会产生有毒的消毒副产物(DBP)。因此，迫切需要对水处理过程中氰化毒素的降解进行详细和仔细的检查，以确保公众的安全饮用水。本项目的总体目标是评估UV/氯处理对饮用水水源中氰基毒素的降解效果，并阐明在相关工艺和环境条件下DBP的形成和毒性机理。为了推进这些目标，合作研究小组建议1)调查两种常见的氰基毒素(微囊藻毒素和柱状精液蛋白)以及一组70个相关的DBPs(包括受监管和优先考虑的未受监管的DBPs)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、卤化物的存在以及溶液pH)对降解效率的作用；3)利用转录组学方法确定包括DBPs在内的转化产物的反应动力学、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UV/氯水处理过程的新基础知识，可以有效地将饮用水水源中的氰基毒素去除到安全水平，同时将有毒DBPS的形成降至最低。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。