SARS-CoV-2 in wastewater treatment plants

Abstract

As for the SARS coronavirus in the 2003 epidemic, the presence of SARS-CoV-2 has been demonstrated in faeces and, in some cases, urine of infected people, as well as in wastewater. This paper proposes a critical review of the state of the art regarding studies on the presence of SARS-CoV-2 in wastewater and sewage sludge, the factors affecting its inactivation and the main proposed treatments, with the aim to provide useful information at operative level in order to better and safer manage wastewater and sewage sludge. Given the lack of literature on SARS-CoV-2, studies involving other HCoVs such as SARS-CoV and HCoV-229E have been also considered. In wastewater, the resistance of SARS-CoV has proven to be very limited, especially at temperatures above 20 °C, and the virus has been easily removed with the use of chlorine (> 0.5 mg L-1 for 30 min). For sewage sludge, based on in vitro experiments, it is suggested to increase the retention times before a possible reuse in agriculture only for precautionary purposes, since SARS-CoV-2 is unlikely to occur in the sludge. SARS-CoV-2 in wastewater might track the epidemic trends: although being extremely promising, an effective and wide application of this approach requires a deeper knowledge of the amounts of viruses excreted through the faeces and the actual detectability of viral RNA in sewage.

Big Data Analysis for Effects of the COVID-19 Outbreak on Ambient PM2.5 in Areas that Were Not Locked Down

“…The decline of O3 in the ambient air after lockdown implementation might be mainly due to lower titration O3 by NOx (Bedi et al, 2020;Brimblecombe et al, 2020;Kumari et al, 2020b). At the same time, O3 was significantly increased due to reductions in human and economic activities, traffic restrictions, and decreases in energy consumption during lockdowns for COVID-19 in various countries in comparison to the prelockdown period (Collivignarelli et al, 2020;Dantas et al, 2020;Kerimray et al, 2020;Li et al, 2020aLi et al, , 2020bMahato et al, 2020;Nakada and Urban, 2020;Otmani et al, 2020;Wang et al, 2020c). The improvement of air quality may be associated with the reduced emissions from transportation, which is related to NO2 reductions, and the manufacturing industry, which has been linked to reductions of PM2.5 and CO in China during the COVID-19 outbreak (Wang et al, 2020c).…”

The role of wastewater treatment plants as tools for SARS-CoV-2 early detection and removal

“…It potentially provides real time information on wastewater contaminants [ 72 ] and was first used in 2001 to evaluate illicit drug usage [ 73 ]. More recently, WBE has been proposed for the early detection of viral outbreaks [ [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] , [82] ] as well as for the persistence of viral indicators in the aquatic environment [ 75 , 83 ]. The methods used are high throughput RNA sequencing (RNA-Seq) more commonly than PCR (qRT-PCR) [ 75 , 84 ].…”