Morrison Christina M, Hogard Samantha, Pearce Robert, Gerrity Daniel, von Gunten Urs, Wert Eric C
Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV 89193-9954, USA.
Civil and Environmental Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; Hampton Roads Sanitation District, P.O. Box 5911, Virginia Beach, VA 23471-0911.
Water Res. 2022 May 1;214:118206. doi: 10.1016/j.watres.2022.118206. Epub 2022 Feb 18.
Viruses, Giardia cysts, and Cryptosporidium parvum oocysts are all major causes of waterborne diseases that can be uniquely challenging in terms of inactivation/removal during water and wastewater treatment and water reuse. Ozone is a strong disinfectant that has been both studied and utilized in water treatment for more than a century. Despite the wealth of data examining ozone disinfection, direct comparison of results from different studies is challenging due to the complexity of aqueous ozone chemistry and the variety of the applied approaches. In this systematic review, an analysis of the available ozone disinfection data for viruses, Giardia cysts, and C. parvum oocysts, along with their corresponding surrogates, was performed. It was based on studies implementing procedures which produce reliable and comparable datasets. Datasets were compiled and compared with the current USEPA Ct models for ozone. Additionally, the use of non-pathogenic surrogate organisms for prediction of pathogen inactivation during ozone disinfection was evaluated. Based on second-order inactivation rate constants, it was determined that the inactivation efficiency of ozone decreases in the following order: Viruses >> Giardia cysts > C. parvum oocysts. The USEPA Ct models were found to be accurate to conservative in predicting inactivation of C. parvum oocysts and viruses, respectively, however they overestimate inactivation of Giardia cysts at ozone Ct values greater than ∼1 mg min L. Common surrogates of these pathogens, such as MS2 bacteriophage and Bacillus subtilis spores, were found to exhibit different inactivation kinetics to mammalian viruses and C. parvum oocysts, respectively. The compilation of data highlights the need for further studies on disinfection kinetics and inactivation mechanisms by ozone to better fit inactivation models as well as for proper selection of surrogate organisms.
病毒、贾第虫包囊和隐孢子虫卵囊都是水传播疾病的主要病因，在水和废水处理及水回用过程中的灭活/去除方面具有独特的挑战性。臭氧是一种强大的消毒剂，在水处理中已被研究和应用了一个多世纪。尽管有大量关于臭氧消毒的数据，但由于水相臭氧化学的复杂性和应用方法的多样性，不同研究结果的直接比较具有挑战性。在这项系统评价中，对病毒、贾第虫包囊和隐孢子虫卵囊及其相应替代物的现有臭氧消毒数据进行了分析。该分析基于实施能产生可靠且可比数据集程序的研究。汇编了数据集并与美国环境保护局（USEPA）当前的臭氧Ct模型进行了比较。此外，还评估了使用非致病性替代生物来预测臭氧消毒过程中病原体灭活的情况。根据二级灭活速率常数，确定臭氧的灭活效率按以下顺序降低：病毒>>贾第虫包囊>隐孢子虫卵囊。发现USEPA Ct模型在预测隐孢子虫卵囊和病毒的灭活方面分别准确到保守，但在臭氧Ct值大于约1毫克·分钟/升时，它们高估了贾第虫包囊的灭活情况。这些病原体的常见替代物，如MS2噬菌体和枯草芽孢杆菌孢子，分别被发现对哺乳动物病毒和隐孢子虫卵囊表现出不同的灭活动力学。数据汇编凸显了需要进一步研究臭氧的消毒动力学和灭活机制，以更好地拟合灭活模型以及正确选择替代生物。
