Abstract:
Water disinfection during drinking water production is one of the most important processes to ensure safe drinking water, which is gaining even more importance due to the increasing impact of climate change. With specific reaction partners, chemical oxidants can form secondary oxidants, which can cause additional damage to bacteria. Cases in point are chlorine dioxide which forms free available chlorine (e.g., in the reaction with phenol) and ozone which can form hydroxyl radicals (e.g., during the reaction with natural organic matter). The present work reviews the complex interplay of all these reactive species which can occur in disinfection processes and their potential to affect disinfection processes. A quantitative overview of their disinfection strength based on inactivation kinetics and typical exposures is provided. By unifying the current data for different oxidants it was observable that cultivated wild strains (e.g., from wastewater treatment plants) are in general more resistant towards chemical oxidants compared to lab-cultivated strains from the same bacterium. Furthermore, it could be shown that for selective strains chlorine dioxide is the strongest disinfectant (highest maximum inactivation), however as a broadband disinfectant ozone showed the highest strength (highest average inactivation). Details in inactivation mechanisms regarding possible target structures and reaction mechanisms are provided. Thereby the formation of secondary oxidants and their role in inactivation of pathogens is decently discussed. Eventually, possible defense responses of bacteria and additional effects which can occur in vivo are discussed.
摘要:
饮用水生产过程中的水消毒是确保饮用水安全的最重要过程之一,由于气候变化的影响越来越大,这一点变得越来越重要。有了特定的反应伙伴,化学氧化剂可以形成次级氧化剂,这会对细菌造成额外的伤害。合适的例子是形成游离有效氯的二氧化氯(例如,在与苯酚的反应中)和可以形成羟基的臭氧(例如,在与天然有机物反应期间)。本工作回顾了在消毒过程中可能发生的所有这些反应性物种的复杂相互作用及其影响消毒过程的潜力。提供了基于灭活动力学和典型暴露的消毒强度的定量概述。通过统一不同氧化剂的当前数据,可以观察到培养的野生菌株(例如,与来自同一细菌的实验室培养菌株相比,来自废水处理厂的菌株)通常对化学氧化剂更具抵抗力。此外,可以证明,对于选择性菌株,二氧化氯是最强的消毒剂(最高的最大灭活),然而,作为宽带消毒剂,臭氧显示出最高的强度(最高的平均灭活)。提供了关于可能的靶结构和反应机制的失活机制的细节。因此,有针对性地讨论了次级氧化剂的形成及其在病原体灭活中的作用。最终,讨论了细菌可能的防御反应以及可能在体内发生的其他作用。