Sources, fates and treatment strategies of typical viruses in urban sewage collection/treatment systems: A review

Abstract

The ongoing coronavirus pandemic (COVID-19) throughout the world has severely threatened the global economy and public health. Due to receiving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a wide variety of sources (e.g., households, hospitals, slaughterhouses), urban sewage treatment systems are regarded as an important path for the transmission of waterborne viruses. This review presents a quantitative profile of the concentration distribution of typical viruses within wastewater collection systems and evaluates the influence of different characteristics of sewer systems on virus species and concentration. Then, the efficiencies and mechanisms of virus removal in the units of wastewater treatment plants (WWTPs) are summarized and compared, among which the inactivation efficiencies of typical viruses by typical disinfection approaches under varied operational conditions are elucidated. Subsequently, the occurrence and removal of viruses in treated effluent reuse and desalination, as well as that in sewage sludge treatment, are discussed. Potential dissemination of viruses is emphasized by occurrence via aerosolization from toilets, the collection system and WWTP aeration, which might have a vital role in the transmission and spread of viruses. Finally, the frequency and concentration of viruses in reclaimed water, the probability of infection are also reviewed for discussing the potential health risks.

Keywords: Collection systems; Fate; Removal; Virus; WWTP treatment units.

Graphical abstract

Fig. 1

Persistence of typical virus in wastewater at varying temperature , , , , . (SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; SARS-CoV, severe acute respiratory syndrome coronavirus; MNV, Murine Norovirus; MHV, Mouse hepatitis virus; AdV, adenovirus; PV, poliovirus)

Fig. 2

Mechanism and log removal efficiency of different viruses during different WWTP units operation , , , , , , , , , , , , . (SARS-CoV-2, severe acute respiratory syndrome coronavirus2; PyVs, polyomavirus; RoV, rotavirus; NoV GII, norovirus GII; NoV GI, norovirus GI; EV, enterovirus; AdV, adenovirus; HTtV, human torque teno virus; HPyV, Human polyomavirus; PLVs, primate lentivirus; AV, astrovirus; SaV, sapovirus).

Fig. 3

Concentration and positive detection rates of typical viruses in WWTP effluent of (a) American Continent , , , , , , , (b) Europe , , , , , (c) Asia , , , , , , , , , (d) Africa , , , , . (EVs, enterovirus; HAV, hepatitis A virus; HAdV, human adenovirus; JCPyV, JC Polyomavirus; NoV GII, norovirus GII; NoV GI, norovirus GI; RoV, rotavirus; RV-A, rotavirus A; SaVs, sapovirus; HAstV, Human astrovirus; HEV, hepatitis E virus; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; AdV, adenovirus; AiVs, Avian influenza virus; HBoV, Human bocavirus; HPV, Human papillomavirus; HPyV, human polyomavirus; NoV, norovirus).

Fig. 4

Dissemination of virus via aerosol route in the whole process of sewage collection, transmission and treatment , , , . (a) Concentrations of MS2 and Phi6 in aerosols generated in lab-scale models of toilet and converging sewer pipes. (b) Concentrations of typical viruses in aerosols generated from different units of WWTP. (c) Overview of potential virus dissemination via aerosol route during wastewater collection, transmission and treatment. (Different font colors in (a) and column colors in (b) indicate that the data come from different articles) (RoV, rotavirus; AdV, adenovirus; NoV GII, norovirus GII; HAV, hepatitis A virus; NoV GI, norovirus GI.)