Performance of wastewater reclamation systems in enteric virus removal

Where do we stand to oversee the coronaviruses in aqueous and aerosol environment? Characteristics of transmission and possible curb strategies

“…The enteric viruses, norovirus, and adenoviruses are commonly waterborne non-enveloped viruses and are normally used as surrogates for treatment performance evaluations in the aquatic environment [103] , [104] , [105] , [106] . Based on the collective data, the level of virus removal in secondary treatment has a variable feature between less than 1 log unit to greater than 4 log units, depending on the treatment process used and the virus types [107] , [108] , [109] , [110] . The mechanism of remove viruses in activated sludge is mainly attributed to sludge flocs adsorption and subsequent separation in secondary clarifiers [108] .…”

“…Regardless of the process applied, disinfection highly depends on wastewater physicochemical properties and operational conditions, especially the product of disinfectant concentration and contact time (CT value). A number of studies have been carried out and have demonstrated that the reduction in non-enveloped viruses, such as human adenovirus (HAdV), enterovirus (EV), in effluent treated with UV or chemical disinfection is more effective, with 0.1 to 5 log units, and point out coronaviruses are more sensitive to UV than non-enveloped viruses [107] , [109] , [112] , [113] . For the inactivation of coronaviruses in wastewater, a study to explore the inactivation of SARS virus in municipal wastewater by chlorine and chlorine dioxide showed that the chlorine dosage of 20 mg L -1 , a contact time of over 1 minute, and free chlorine residual of > 0.4 mg L -1 were found to complete coronaviruses inactivation, while chlorine dioxide needs to be using a dose of 40 mg L -1 with a required contact time of >5 minutes to achieve the same effect [58] .…”

“…As the advanced treatment process, reclaimed water is similar to that of ordinary DWTPs, the possible prevention and control strategies for the water-related virus in DWTPs are suitable for reclaimed water management [107] , [128] . Based on the data during the outbreak of SARS and MERS, most DWTPs systems that meet the virus removal/inactivation regulations are effective for coronaviruses control.…”

Water reclamation and reuse

“…The removal of three species of human viral pathogens in reclaimed water from four WRRFs in São Paulo (MSP), Brazil, was evaluated (Prado et al, 2019). Of the four WRRFs, the membrane bioreactor (MBR)/RO systems as part of tertiary treatment demonstrated the highest virus removal efficiencies (2.3-2.9 log 10 ).…”

Disinfection and antimicrobial processes

“…The occurrence of viruses in urban wastewaters and the efficacy of treatment systems in handling them also received research attention in 2019. Prado et al (2019) evaluated the distribution and viral burden of human adenovirus (HAdV), Species A rotaviruses (RVA), and JC polyomavirus (JCV) in urban wastewaters, secondary effluents and reuse water produced by four large wastewater treatment plants in metropolitan São Paulo (MSP), Brazil. The article concluded that, as compared with JCV, HAdV was found to be a more relevant viral indicator to assess human fecal pollution in the reuse water samples due to its greater persistence in different wastewater treatment stages and disinfection processes.…”