Photolysis of free chlorine to hydroxyl radical by sunlight and ultraviolet irradiation for enhanced disinfection of chlorine-resistant waterborne pathogens

阳光和紫外线照射将游离氯光解为羟基自由基，增强耐氯水生病原体的消毒

• 批准号: 1236303
• 负责人: Michael Dodd
• 金额: $ 35.41万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1236303&HistoricalAwards=false
• 关键词: Photolysis; free; chlorine; hydroxyl; radical

1236303DoddFree available chlorine (FAC) remains the most widely used disinfectant in drinking water practice worldwide. It is cheap, easily utilized as a disinfectant, portable, and in general highly effective for achieving the inactivation of a wide variety of waterborne microbial pathogens. However, it is known to be relatively ineffective as a primary disinfectant of such important pathogenic agents as Cryptosporidium parvum, Mycobacterium avium, and Giardia lamblia, This has led to widespread adoption of more effective, but often substantially more capital-, equipment-, and energy-intensive alternative disinfectants such as UV light and ozone. Recent findings suggest that inactivation of chlorine-recalcitrant microbial pathogens may actually be achievable at considerably lower expense by utilizing sunlight or monochromatic UV light to photolyze FAC to such highly-reactive oxidant species as hydroxyl radical, atomic oxygen, and ozone during conventional chlorination. In such an approach, FAC and photochemically-generated oxidants may act in tandem to yield substantially greater inactivation of various waterborne pathogens than would be achievable using chlorine alone. This investigation will utilize a combination of chemical and microbiological tools to quantify inactivation of chlorine-resistant viral, bacterial, and protozoan pathogens during conventional chlorination processes enhanced by FAC photolysis. The primary objective of this work will be to evaluate the use of sunlight for photochemical enhancement of chlorination processes. However, the investigation will also focus on potential applications of monochromatic and polychromatic UV light sources, on account of their growing frequency of application in drinking water treatment. The project team will develop and optimize experimental and analytical procedures for quantifying pathogen inactivation during photochemically-enhanced chlorination by first utilizing two common surrogates for waterborne pathogens B. subtilis spores and MS2 bacteriophage, followed by the chlorine-resistant human pathogens M. avium, Coxsackievirus B5 (CVB5), and C. parvum. These procedures will subsequently be utilized to examine the influence of such critical parameters as pH, water temperature, alkalinity, and matrix oxidant demand on inactivation efficiency for each pathogen under simulated sunlight, natural sunlight, and various artificial UV light sources in buffered laboratory reagent water systems, as well as in real water matrixes acquired from municipal water utilities in the Puget Sound region. Particular emphasis will be placed on development of kinetic models for pathogen inactivation that take into account measured water quality parameters and spectral irradiance data. Finally, formation potentials of organic and inorganic DBPs likely to be generated during application of photochemically-enhanced chlorination (e.g., trihalomethanes, haloacetic acids, ClO3-, ClO4-, and BrO3-) will be quantified under a variety of scenarios relevant to full-scale application. In addition to establishing a theoretical framework for modeling chlorine-resistant pathogen inactivation during photochemically-enhanced chlorination, this project will provide an extensive dataset for M. avium, CVB5, and C. parvum inactivation under a wide variety of conditions applicable to full-scale water treatment (including variable irradiation wavelength, intensity, temperature, pH, and alkalinity). This research could support the photochemical augmentation of conventional drinking water chlorination processes at full-scale, with minimal equipment and process retrofit. Application of such an approach could have substantial benefits over existing alternatives to chlorine-based disinfection processes. First, chlorination is used in the vast majority of water treatment facilities. Second, utilization of solar radiation in particular as a light source could net significant cost and energy savings in comparison to processes utilizing ozone or artificial UV light. In addition, if a UV process is already in place at a facility, that process could quite easily be adapted for photochemically-enhanced chlorination simply by dosing FAC upstream of the UV reactor(s). Furthermore, sunlight-enhanced chlorination could prove exceptionally useful for ensuring disinfection of chlorine-resistant pathogens during point-of-use applications in developed and developing societies, on account of its expected low costs and ease of implementation.

1236303Dodd 游离有效氯 (FAC) 仍然是全球饮用水实践中使用最广泛的消毒剂。它价格便宜，易于用作消毒剂，便于携带，并且通常对于灭活多种水传播微生物病原体非常有效。然而，众所周知，它作为主要病原体（如小隐孢子虫、鸟分枝杆菌和蓝氏贾第鞭毛虫）的主要消毒剂相对无效。这导致广泛采用更有效但通常需要更多资金、设备和技术的消毒剂。能源密集型替代消毒剂，例如紫外线和臭氧。最近的研究结果表明，在传统氯化过程中，利用太阳光或单色紫外光将 FAC 光解为羟基自由基、原子氧和臭氧等高反应性氧化剂，实际上可以以相当低的成本实现对氯顽固微生物病原体的灭活。在这种方法中，FAC 和光化学产生的氧化剂可以协同作用，对各种水传播病原体产生比单独使用氯更大的灭活效果。这项研究将结合化学和微生物工具来量化 FAC 光解增强的传统氯化过程中耐氯病毒、细菌和原生动物病原体的灭活情况。这项工作的主要目标是评估利用阳光来增强氯化过程的光化学作用。然而，由于单色和多色紫外光源在饮用水处理中的应用越来越频繁，该研究还将重点关注单色和多色紫外光源的潜在应用。该项目团队将开发和优化实验和分析程序，用于量化光化学强化氯化过程中病原体的灭活，首先利用两种常见的水源病原体枯草芽孢杆菌孢子和MS2噬菌体替代品，然后使用耐氯人类病原体鸟支原体、柯萨奇病毒B5 (CVB5) 和小小念珠菌。随后将利用这些程序来检查 pH、水温、碱度和基质氧化剂需求等关键参数对缓冲实验室试剂水中的模拟阳光、自然阳光和各种人造紫外光源下每种病原体灭活效率的影响系统，以及从普吉特海湾地区市政供水公司获得的真实水矩阵。将特别强调开发病原体灭活动力学模型，该模型考虑到测量的水质参数和光谱辐照度数据。最后，在光化学强化氯化过程中可能产生的有机和无机 DBP（例如三卤甲烷、卤乙酸、ClO3-、ClO4- 和 BrO3-）的形成潜力将在与全光相关的各种情景下进行量化。规模应用。除了建立光化学强化氯化过程中耐氯病原体灭活模型的理论框架外，该项目还将提供适用于全尺寸的各种条件下的鸟分枝杆菌、CVB5 和微小念珠菌灭活的广泛数据集。水处理（包括可变照射波长、强度、温度、pH 值和碱度）。这项研究可以支持传统饮用水氯化过程的光化学增强，只需最少的设备和工艺改造。与现有的氯消毒工艺替代方案相比，应用这种方法可能具有显着的优势。首先，绝大多数水处理设施都采用氯化法。其次，与利用臭氧或人造紫外线的工艺相比，特别是利用太阳辐射作为光源可以显着节省成本和能源。此外，如果设施中已采用紫外线工艺，则只需在紫外线反应器上游添加 FAC，即可轻松地将该工艺适用于光化学强化氯化。此外，由于其预期的低成本和易于实施，阳光强化氯化对于确保在发达国家和发展中国家的使用点应用期间对耐氯病原体的消毒特别有用。

项目成果

Characterization of disinfection byproduct formation and associated changes to dissolved organic matter during solar photolysis of free available chlorine

游离有效氯的太阳光解过程中消毒副产物形成和溶解有机物相关变化的表征

• DOI: 10.1016/j.watres.2018.09.022
• 发表时间: 2018
• 期刊: Water Research
• 影响因子: 12.8
• 作者: Tessora R Young;Wentao Li;Alan Guo;Gregory V Korshin;Michael C Dodd
• 通讯作者: Michael C Dodd

Enhanced Inactivation of Bacillus subtilis Spores during Solar Photolysis of Free Available Chlorine

• DOI: 10.1021/es401906x
• 发表时间: 2013-11-19
• 期刊: ENVIRONMENTAL SCIENCE & TECHNOLOGY
• 影响因子: 11.4
• 作者: Forsyth, Jenna E.;Zhou, Peiran;Dodd, Michael C.
• 通讯作者: Dodd, Michael C.

Enhanced Inactivation of Cryptosporidium parvum Oocysts during Solar Photolysis of Free Available Chlorine

• DOI: 10.1021/ez500270u
• 发表时间: 2014-10
• 期刊: Environmental Science and Technology Letters
• 影响因子: 10.9
• 作者: Peiran Zhou;G. Giovanni;J. Meschke;Michael C. Dodd

Rapid determination of trace haloacetic acids in water and wastewater using non-suppressed ion chromatography with electrospray ionization-tandem mass spectrometry

使用非抑制离子色谱电喷雾电离串联质谱快速测定水和废水中的痕量卤乙酸

• DOI: 10.1016/j.scitotenv.2020.142297
• 发表时间: 2021-02-01
• 期刊: SCIENCE OF THE TOTAL ENVIRONMENT
• 影响因子: 9.8
• 作者: Cheng, Shi;Wu, Ya-Ping;Li, Ai-Min
• 通讯作者: Li, Ai-Min