Impact of wastewater particles on ultraviolet and chlorine disinfection and public health

保护公众健康是污水处理设施的首要目标，消毒是控制病原体的最重要过程。以前的研究已经证明，废水颗粒的存在会影响消毒过程，大肠菌群是最常用的指示微生物，与颗粒相关，在处理厂应用的典型和高得多的消毒剂量下存活。这是麻烦的，因为通过消毒过程与颗粒相关的大肠菌群的存活可能表明其他更具抗性的健康相关微生物的存活，并且可能对公共健康构成威胁。本研究的主要目的是确定在何种程度上微生物与颗粒相关联，它们如何分布在絮凝体结构内，以及它们的空间分布如何影响它们对氯和紫外线辐射消毒的反应。另一个目标是确定紫外线和氯可以渗透到絮凝物结构中多远，并能够将颗粒相关的微生物杀灭。该研究将采用分子方法的组合，包括荧光原位杂交（FISH），间接免疫荧光，和单叠氮乙锭（EMA）染色与激光细胞术相结合，以提供有关紫外线和氯消毒后颗粒相关微生物的数量，分布，身份和活力的信息。该研究将提高对污水处理厂消毒过程中病原体命运和存活的理解。获得的知识将有利于监管机构，公用事业和顾问，并将有助于改善现有和未来消毒过程的性能和设计。这些知识有助于为废水处理设施运营商提供改进的过程控制，以实现消毒目标的一致性，并且是保护公众健康的第一步。

Protecting public health is a primary objective of wastewater treatment facilities, and disinfection is the most important process to control pathogens. Previous research has documented that presence of wastewater particulates affect the disinfection process, and coliform bacteria, the most commonly used indicator microorganism, associated with particles survive typical and much higher doses of disinfection applied in treatment plants. This is troublesome because the survival of particle-associated coliform through a disinfection process may indicate the survival of other more resistant health related microorganisms and may pose a threat to public health. The main objective of this research is to determine to what extent microorganisms are associated with particles, how they are distributed within the floc structure, and how their spatial distribution influences their response to disinfection by chlorine and UV radiation. Another objective is to determine how far into the floc structure UV and chlorine can penetrate and be able to inactivate particle-associated microorganisms. The research will employ a combination of molecular methods, including fluorescence in situ hybridization (FISH), indirect immunofluorescence, and ethidium monoazide (EMA) staining coupled with laser cytometry to provide information on the number, distribution, identity, and viability of particle-associated microorganisms after UV and chlorine disinfection. The study will improve the understanding of the fate and survival of pathogens through a disinfection process in a wastewater treatment plant. The acquired knowledge will benefit regulators, utilities, and consultants, and will help to improve the performance and design of existing and future disinfection processes. This knowledge is useful to provide wastewater facility operators with improved process controls, for consistency in meeting disinfection targets, and is the first step in protecting public health.