Abstract：
Fecal shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by infected persons into wastewater was documented early during the COVID-19 pandemic, thereby stimulating inquiries into the effectiveness of municipal wastewater treatment processes for the reduction of infectious viruses. In wastewater treatment plants, free chlorine has traditionally been the disinfectant utilized due to its low cost and high efficacy. However, regulations limiting disinfection by-products have prompted a shift to chloramination in many areas of the United States. While studies regarding the effectiveness of free chlorine against many viral agents are abundant, the efficacy of monochloramine (NH2Cl) has been less well researched. This study aimed to determine the effectiveness of pre-formed monochloramine for disinfection of human coronavirus 229E (HCoV-229E) in both phosphate-buffered saline (PBS) and reclaimed water from a water reclamation plant in Tucson, Arizona. Reclaimed water was sampled over the course of six months (August 2020 to November 2020), and dosed with monochloramine at 3 mg/L. An additional 1 mg/L free ammonia was added to simulate the operational conditions of the treatment plant. Viability was determined using MRC-5 host cell monolayers, using the TCID50 assay method. An average Ct99.9 (concentration of disinfectant multiplied by the contact time to achieve a 99.9 % reduction of the target organism) of 176 mg*min/L monochloramine was determined. No significant difference in inactivation rate was observed between the dosed reclaimed water and phosphate buffered saline (PBS). These data indicate that monochloramine is an effective disinfectant for coronaviruses. They also indicate that the water matrix type did not significantly impact the disinfection efficacy of monochloramine against HCoV-229E in reclaimed wastewater compared to PBS.
摘要：
在COVID-19大流行期间，有记录称，感染者将严重急性呼吸道综合症冠状病毒2（SARS-CoV-2）排泄到废水中，从而激发了对市政污水处理过程的有效性的调查，以减少传染性病毒。在污水处理厂，游离氯由于其低成本和高功效而传统上一直是使用的消毒剂。然而,限制消毒副产品的法规促使美国许多地区转向氯胺化。虽然关于游离氯对抗许多病毒剂的有效性的研究是丰富的，一氯胺（NH2Cl）的功效研究较少。这项研究旨在确定预先形成的一氯胺在磷酸盐缓冲盐水（PBS）和来自图森水再生厂的再生水中对人冠状病毒229E（HCoV-229E）进行消毒的有效性，亚利桑那.回收水的采样时间为六个月(2020年8月至2020年11月)，并以3mg/L的剂量加入一氯胺。添加额外的lmg/L游离氨以模拟处理设备的操作条件。使用MRC-5宿主细胞单层确定活力，使用TCID50测定方法。测定176mg*min/L一氯胺的平均Ct99.9(消毒剂的浓度乘以实现目标生物体减少99.9%的接触时间)。在给药的再生水和磷酸盐缓冲盐水(PBS)之间没有观察到失活速率的显著差异。这些数据表明一氯胺是冠状病毒的有效消毒剂。它们还表明,与PBS相比,水基质类型不显著影响单氯胺对再生废水中的HCoV-229E的消毒效力。
