Coronavirus disease 2019 (COVID-19) and its spread prevention actions (SPAs) have affected a large number of human activities globally in 2020-2021. Temporary lockdowns, stay-at-home policies, movement restrictions, and personal health care actions have relatively changed the daily life routine in urban areas which can eventually affect the characteristics of municipal wastewater (MW). This study evaluates the performance of wastewater treatment plants (WWTPs) during COVID-19 pandemic and related SPAs. This evaluation also considers MW variations in quality and quantity and compares the performance of WWTPs (2020) with earlier data (2015–2019). For this purpose, 23 WWTPs located in Isfahan province, Iran, were chosen as the study area and classified based on their locations, biological treatment unit, and capacities. Results indicate that the inflow of WWTPs increased 20 % on average during SPAs, while the concentrations of COD and BOD in MW decreased 23 and 16 %, respectively. Nevertheless, the performance of WWTPs remained rather constant. It is concluded that increasing the dilute domestic proportion of MW, particularly in smaller communities, as a matter of COVID-19 SPAs could not impose adverse impacts on wastewater treatment operations and pollution removal. Different types of secondary treatment units, such as activated sludge, stabilization pond, and aerated lagoon showed stable performances. However, disinfection was enhanced in WWTPs in order to reduce the probability of viral transmission via wastewater for reuse. This study also recommends that the characteristics of MW, and not treated wastewater, can be used as an indicator for coordinating SPAs in similar epidemics. This notification can be helpful for the management of WWTPs and risk control in urban areas.

2019 年冠状病毒病（COVID-19）及其传播预防行动（SPA）在 2020-2021 年影响了全球大量人类活动。临时封锁、居家政策、行动限制和个人医疗保健行动相对改变了城市地区的日常生活习惯，最终会影响城市废水（MW）的特性。本研究评估了 COVID-19 大流行期间废水处理厂 (WWTP) 和相关 SPA 的性能。该评估还考虑了MW在质量和数量上的变化，并将污水处理厂的性能（2020年）与早期数据（2015-2019年）进行了比较。为此，选择位于伊朗伊斯法罕省的 23 个污水处理厂作为研究区域，并根据其位置、生物处理单元和容量进行分类。结果表明，SPA 期间污水处理厂的进水量平均增加了 20%，而 MW 中的 COD 和 BOD 浓度分别下降了 23% 和 16%。尽管如此，污水处理厂的绩效仍然相当稳定。结论是，由于 COVID-19 SPA 的问题，增加兆瓦的稀释家庭比例，特别是在较小的社区，不会对废水处理操作和污染清除产生不利影响。活性污泥、稳定池、曝气池等不同类型的二级处理装置性能稳定。然而，污水处理厂加强了消毒，以减少通过废水再利用传播病毒的可能性。这项研究还建议，MW 的特征（而不是未经处理的废水）可以用作在类似流行病中协调 SPA 的指标。 该通知对于城市污水处理厂的管理和风险控制具有重要意义。