SGER: Reactive Saturation Behavior and Oxidant Induced Coagulation of Pathogenic Mycobacterial and Bacterial Spores

SGER：病原分枝杆菌和细菌孢子的反应饱和行为和氧化剂诱导凝固

• 批准号: 0229220
• 负责人: Mark Hernandez
• 金额: $ 5.46万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0229220&HistoricalAwards=false
• 关键词: SGER; Reactive; Saturation; Behavior; Oxidant

0229220 Hernandez The last several decades, numerous disinfection studies have been executed to determine the inactivation response of many different types of microorganisms exposed to various disinfectants. EPA's current disinfection standards, which regulate the performance of public water treatment systems, have been built upon such studies (AWWA, 1999). Of notable concern in the water treatment field is the fact that current federal disinfection standards are generalized criteria that must be applied to a wide range of source waters, each with their own characteristics. While both the scientific and regulatory communities clearly recognize that disinfection performance can be significantly impacted by source water characteristics, only recently have disinfection studies been chartered (Dow, 2001) to determine the impact of common water quality parameters (e.g. turbidity and natural organic matter (NOM) content) on the inactivation of "emerging" bacterial pathogens, bacterial spores, and protozoan (oo)cysts by ozone. The main engineering "process" variables affecting the disinfection performance of water treatment works are disinfectant dose, mixing regime, and residence (contact) time - these parameters form the basis of the modern "CT" concept, which was first introduced by Chick and Watson (Gyurek and Finch, 1998) nearly a century ago. The CT concept was originally derived from observations of vegetative bacterial cells (i.e. not spores) and has been widely accepted as a robust engineering tool for disinfection system designs. Over the last generation, conventional CT disinfection models used for chlorine have been extended to include O3. The engineering of ozone (O3) disinfection systems for public water supplies has received increasing scientific and regulatory attention because of the potential for chlorine to form by-products, which present significant human health risks. While ozone is gaining popularity in full-scale disinfection applications, its germicidal abilities have been studied for many years. O3 appears to be more effective than chlorine-based disinfectants against the most oxidant-resistant microorganism physiologies - bacterial spores and protozoan (oo)cysts. However, ozone is extremely reactive and the kinetics of ozone-associated disinfection reactions is so rapid, that understanding ozone inactivation mechanisms with different microorganisms is extremely challenging (Elovitz et al., 2000). Ozone can induce the aggregation of organic particulate matter (Chandrakanth, 1996), but because of culturing artifacts, its potential for inducing coagulation of bacteria, has not been documented. Motivation and Research Needs. Modern disinfection engineering remains rooted in a CT response model that is predominantly based on the observations of culturing dispersed vegetative bacterial cells from synthetic waters. While conventional CT models have extended some reasonable protection for water supplies using chlorine, their predictive capacity needs to be more comprehensive in order to leverage the disinfection capabilities and advantages of ozone. Projected increases for ozone use provide motivation to study its coagulation effects and disinfection efficacy against emerging pathogens, with a focus on its inactivation mechanisms against resilient physiologies.

0229220埃尔南德斯在过去的几十年里，已经进行了大量的消毒研究，以确定暴露于各种消毒剂的许多不同类型的微生物的灭活反应。美国环保署目前的消毒标准，规范公共水处理系统的性能，已经建立在这些研究（AWWA，1999年）。在水处理领域值得注意的是，目前的联邦消毒标准是通用的标准，必须适用于各种各样的源沃茨，每一种都有自己的特点。虽然科学界和监管界都清楚地认识到消毒性能会受到水源特性的显著影响，但直到最近才批准了消毒研究（Dow，2001年），以确定常见水质参数的影响（例如浊度和天然有机物（NOM）含量）对“新兴”细菌病原体、细菌孢子、和原生动物（oo）包囊。影响水处理厂消毒性能的主要工程“过程”变量是消毒剂剂量、混合制度和停留（接触）时间-这些参数构成了现代“CT”概念的基础，该概念由Chick和沃森（Gyurek和Finch，1998）在近世纪前首次引入。CT概念最初来源于对营养细菌细胞（即非孢子）的观察，并已被广泛接受为消毒系统设计的强大工程工具。在上一代中，用于氯的传统CT消毒模型已扩展到包括O3。臭氧（O3）消毒系统的公共供水工程受到越来越多的科学和监管关注，因为氯形成副产品的可能性，这对人类健康构成重大风险。虽然臭氧在全面消毒应用中越来越受欢迎，但其杀菌能力已研究多年。O3似乎比氯基消毒剂更有效地对抗最耐氧化剂的微生物生理-细菌孢子和原生动物（oo）包囊。然而，臭氧具有极强的反应性，并且臭氧相关的消毒反应的动力学是如此迅速，以至于理解不同微生物的臭氧灭活机制是极其具有挑战性的（Elovitz等人，2000年）。臭氧可以诱导有机颗粒物的聚集（Chandrakanth，1996），但由于人工培养，其诱导细菌凝结的潜力尚未被记录。动机和研究需求。现代消毒工程仍然植根于CT响应模型，该模型主要基于从合成沃茨水中培养分散的营养细菌细胞的观察结果。虽然传统的CT模型已经为使用氯的供水提供了一些合理的保护，但它们的预测能力需要更全面，以便利用臭氧的消毒能力和优势。预计臭氧使用量的增加为研究其对新出现的病原体的凝血效果和消毒效果提供了动力，重点是其对弹性生理学的灭活机制。