Investigation on the electrodes applied in the locally enhanced electric field treatment (LEEFT) for water disinfection

水消毒局部增强电场处理（LEEFT）电极的研究

• 批准号: 2203162
• 负责人: Xing Xie
• 金额: $ 40万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2203162&HistoricalAwards=false
• 关键词: Investigation; electrodes; applied; locally; enhanced

Water disinfection is essential for the protection of public health. Chemical oxidants such as chlorine, chloramine, ozone, and hydrogen peroxide are widely utilized in water treatment as disinfectants to deactivate water-borne pathogens from drinking water sources. Unfortunately, these chemical oxidants can also react with organic contaminants and dissolved organic matter to generate various disinfection byproducts such as trihalomethanes and N-nitroso-dimethylamine which can adversely impact human health due to their toxicity. Locally enhanced electric field treatment (LEEFT) has emerged as a promising disinfection process that can deactivate water-borne pathogens without using chemicals. During water disinfection by LEEFT, a device with two parallel plate electrodes is utilized to generate a strong electric field that can deactivate microbial pathogens by disrupting their cell membranes as the water flows through the device. Although high water disinfection efficiencies have been demonstrated using lab scale LEEFT devices, electrode durability remains a critical and unresolved challenge limiting device lifespans to only a few days. The overarching goal of this project is to improve the durability and lifespan of LEEFT electrodes to enable their utilization in water disinfection. To advance this goal, the Principal Investigators propose to study the process and mechanisms of erosion of LEEFT electrodes with the aim of identifying effective solutions for improving their durability and lifespans. The successful completion of this research will benefit society through the generation of new fundamental knowledge and more durable electrodes materials to advance the development and implementation of LEEFT-based water disinfection systems. Additional benefits to society will be achieved through student education and training including the mentoring of a graduate student at Georgia Tech. Locally enhanced electric field treatment (LEEFT) has emerged as a promising physical disinfection process that utilizes a device with two parallel plate electrodes to generate a strong electric field that can deactivate water-borne microbial pathogens. The electrodes of current LEEFT devices are typically functionalized with nanostructures (e.g., nanowires) to enhance the electric field while reducing the operational voltage required to achieve the target extents and rates of pathogen deactivation. The goals of this project are to 1) investigate the process and mechanisms of erosion of nanowire-functionalized LEET electrodes and 2) identify and evaluate effective solutions for improving electrode durability. To advance these goals, the Principal Investigators (PIs) propose to (1) fabricate and characterize a series of new nanowire-functionalized LEET electrodes and (2) carry out a systematic investigation of the durability of these electrodes when there are exposed to different electrochemical and hydraulic conditions using a combination of imaging and analytic tools to visualize and quantify electrode erosion and transformations including scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). To identify effective solutions for improving electrode durability, the PIs propose to explore several strategies including 1) the fabrication of LEET nanowire electrodes using precursor materials that are less soluble in acids or bind more strongly to the electrode substrates and 2) the coating of LEET nanowire electrodes with thin protective layers. The successful completion of this research has the potential for transformative impact through the generation of new fundamental knowledge and more durable electrode materials to advance the development of next generation high-performance LEEFT systems for water disinfection. To implement the education and outreach activities of the project, the PIs plan to integrate the findings from this research into existing environmental engineering course modules at Georgia Tech. In addition, the PI plans to leverage the GIFT (Georgia Intern Fellowship for Teachers) program at Georgia Tech to provide research training to a local K-12 teacher.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.

水消毒对保护公众健康至关重要。化学氧化剂如氯、氯胺、臭氧和过氧化氢在水处理中被广泛用作消毒剂以灭活来自饮用水源的水传播病原体。不幸的是，这些化学氧化剂也可以与有机污染物和溶解的有机物质反应，产生各种消毒副产物，如三卤甲烷和N-亚硝基二甲胺，由于它们的毒性，这些副产物可以对人类健康产生不利影响。 局部增强电场处理（LEEFT）已成为一种有前途的消毒过程，可以灭活水传播的病原体，而不使用化学品。在通过LEEFT进行水消毒期间，利用具有两个平行板电极的装置来产生强电场，该强电场可以通过在水流过装置时破坏微生物病原体的细胞膜来灭活微生物病原体。尽管已经使用实验室规模的LEEFT设备证明了高的水消毒效率，但电极耐用性仍然是一个关键且未解决的挑战，将设备寿命限制为仅几天。该项目的总体目标是提高LEEFT电极的耐用性和寿命，使其能够用于水消毒。为了推进这一目标，主要研究人员建议研究LEEFT电极的侵蚀过程和机制，旨在确定提高其耐用性和寿命的有效解决方案。 这项研究的成功完成将通过产生新的基础知识和更耐用的电极材料来促进基于LEEFT的水消毒系统的开发和实施，从而造福社会。通过学生教育和培训，包括指导格鲁吉亚理工学院的一名研究生，将为社会带来更多好处。局部增强电场处理（LEEFT）已经成为一种有前途的物理消毒过程，其利用具有两个平行板电极的装置来产生可以使水传播的微生物病原体失活的强电场。当前LEEFT装置的电极通常用纳米结构（例如，纳米线）以增强电场，同时降低实现病原体灭活的目标程度和速率所需的操作电压。该项目的目标是1）研究烧蚀官能化LEET电极的过程和机制，2）识别和评估改善电极耐久性的有效解决方案。为了推进这些目标，主要研究者（PI）建议（1）制造和表征一系列新的具有纳米线功能的LEET电极，以及（2）当暴露于不同的电化学和水力条件时，使用成像和分析工具的组合对这些电极的耐久性进行系统的研究，以可视化和量化电极侵蚀和转化，包括扫描电子显微镜（SEM）与能量色散谱（EDS）、透射电子显微镜（TEM）、X射线衍射（XRD）和X射线光电子能谱（XPS）。为了确定提高电极耐久性的有效解决方案，PI建议探索几种策略，包括1）使用在酸中不太可溶或更强地结合到电极基底的前体材料制造LEET纳米线电极，以及2）用薄保护层涂覆LEET纳米线电极。这项研究的成功完成有可能通过产生新的基础知识和更耐用的电极材料来推动下一代高性能LEEFT水消毒系统的开发。为了实施该项目的教育和推广活动，PI计划将这项研究的结果整合到格鲁吉亚理工学院现有的环境工程课程模块中。此外，PI计划利用GIFT（格鲁吉亚教师实习奖学金）计划在格鲁吉亚技术提供研究培训，以当地K-12教师。该奖项反映了NSF的法定使命，并已被认为是值得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的支持。