JHU/MWH Alliance, Johns Hopkins University, Baltimore, MD 21205, United States.
Department of Environmental Health and Engineering, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, United States.
J Environ Manage. 2018 Sep 1;221:1-9. doi: 10.1016/j.jenvman.2018.04.064. Epub 2018 May 26.
Peracetic acid (PAA) is a strong oxidant/bactericide that has been applied in various industries (e.g., food processing, pharmaceuticals, medical device sterilization, etc.) as a disinfectant. There is increasing interest in using PAA for wastewater disinfection because it does not form halogenated byproducts, and no post-treatment quenching is required. Previous studies have demonstrated good efficiency in controlling bacteria in wastewater, but limited information is available for viruses, especially those hosted by mammals (e.g., norovirus). Therefore, a study on the infectivity reduction of murine norovirus (MNV) was undertaken to evaluate the disinfection efficacy of PAA or UV alone and in combination with UV irradiation in undisinfected secondary effluent from a municipal wastewater reclamation facility (MWW) and phosphate buffer solution (PBS) at pH 7. Experiments employing MS2 bacteriophage were also performed in parallel for comparison purposes. MS2 infectivity reduction was found to be lower than MNV infectivity reduction for each condition studied - PAA, PAA + UV, and UV disinfection. These data suggest that MS2 may not be an appropriate surrogate to accurately predict the reduction of MNV infectivity. UV irradiation, in a dose range of 5-250 mJ/cm, provided linear log inactivation (-log (N/N)) with a regression slope (cmmJ) of 0.031-0.034 and 0.165-0.202 for MS2 and MNV, respectively. UV irradiation provided similar inactivation for MS2 and MNV in both suspensions (PBS or MWW). Low infectivity reduction of MS2 was observed when PAA was used alone at a practical dose of 1.5 mg/L and below. A greater reduction of both MNV and MS2 was observed in PAA disinfection experiments using PBS as the microbial suspension medium, than in secondary effluent. Similar results were observed in PAA + UV experiments, in which greater synergistic effects were found in PBS than in MWW. Results of OH radical formation experiments suggest the presence of radical scavengers in MWW, which resulted in less opportunity for MNV and MS2 to encounter OHradicals. This study also demonstrated that the type of water can have a substantial impact on wastewater disinfection when employing PAA or PAA + UV treatment due to the matrix effect and the presence of radical scavengers, respectively. The results from this study could be employed to aid in the conceptual design of PAA and UV disinfection facilities, especially when norovirus is the organism of concern.
过氧乙酸（PAA）是一种强氧化剂/杀菌剂，已在食品加工、制药、医疗器械消毒等各个行业中用作消毒剂。由于它不会形成卤代副产物，也不需要后处理淬灭，因此人们对使用 PAA 进行废水消毒的兴趣日益增加。先前的研究已经证明了它在控制废水中细菌方面的高效率，但有关病毒的信息有限，尤其是那些由哺乳动物携带的病毒（例如诺如病毒）。因此，进行了一项关于鼠诺如病毒（MNV）感染性降低的研究，以评估 PAA 或 UV 单独以及与市政废水再生设施（MWW）未消毒的二级出水和 pH 值为 7 的磷酸盐缓冲溶液（PBS）中的 UV 照射组合的消毒效果。同时还平行进行了 MS2 噬菌体的实验，以进行比较。研究发现，对于每种研究条件（PAA、PAA+UV 和 UV 消毒），MS2 的感染性降低均低于 MNV 的感染性降低。这些数据表明，MS2 可能不是准确预测 MNV 感染性降低的合适替代物。在 5-250 mJ/cm 的剂量范围内，紫外线照射提供了与 MS2 和 MNV 分别为 0.031-0.034 和 0.165-0.202 的回归斜率（cmmJ）呈线性对数灭活（-log（N/N））。紫外线照射在 PBS 或 MWW 两种悬浮液中均为 MS2 和 MNV 提供了相似的灭活效果。当在 1.5 mg/L 及以下的实际剂量下单独使用 PAA 时，观察到 MS2 的感染性降低很小。在使用 PBS 作为微生物悬浮液介质的 PAA 消毒实验中，观察到 MNV 和 MS2 的降低幅度更大，而在二级出水中则降低幅度较小。在 PAA+UV 实验中也观察到了相似的结果，其中在 PBS 中发现了更大的协同作用，而在 MWW 中则较小。自由基形成实验的结果表明，MWW 中存在自由基清除剂，这使得 MNV 和 MS2 遇到 OH 自由基的机会减少。这项研究还表明，由于基质效应和自由基清除剂的存在，当使用 PAA 或 PAA+UV 处理时，水的类型会对废水消毒产生重大影响。本研究的结果可用于辅助 PAA 和 UV 消毒设施的概念设计，特别是当诺如病毒是关注的生物体时。
