The persistence of pathogenic microorganisms in treated wastewater effluent makes disinfection crucial to achieve wastewater reuse. Membrane processes such as ultrafiltration and reverse osmosis (RO) have shown promising results for virus and other contaminant removal from treated wastewater effluents for reuse application. However, RO produces a concentrate stream which contains high concentrations of pathogens and contaminants that often requires treatment and volume reduction before disposal. Membrane distillation (MD) is a treatment process that can reduce RO concentrate volume while augmenting the potable water supply. MD is also a dual barrier approach for virus removal as it operates at a high temperature and permeates only the vapor phase through the membrane interface. The effects of temperature on viable virus concentration and membrane rejection of viruses in MD are investigated in this study using two nonenveloped phages frequently used as enteric virus surrogates (MS2 and PhiX174) and an enveloped pathogenic virus (HCoV-229E). At typical MD operating temperatures (greater than 65 °C), viable concentrations of all three viruses were reduced by thermal inactivation by more than 6-log 10 for MS2 and PhiX174 and more than 3-log 10 for HCoV-229E. Also, membrane rejection was greater than 6-log 10 for MS2 and PhiX174 and greater than 2.5-log 10 for HCoV-229E.

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Human pathogenic viruses that are present in bioaerosols released by coughing, sneezing, or breathing can contaminate fomites and other inanimate environmental surfaces. Most are enveloped respiratory viruses that are vulnerable to inactivation by a broad spectrum of antimicrobial actives. Quaternary ammonium compounds are highly diverse in structure and are among the most widely utilized antimicrobial agents. The objective of this study was to evaluate two commercially available, ready-to-use quaternary ammonium compound-based disinfectants (one of which also contains a surface binding agent) for antiviral activity against Influenza A (H1N1), human coronavirus 229E, and SARS-CoV-2 (Washington) following a rigorous procedure of wear and abrasions with regular re-inoculations of virus in the presence of a 6% organic soil load. Formulation TF-A demonstrated variable residual efficacy against the three viruses, achieving log10reductions of 1.62, 3.33, and 0.92, respectively. Formulation TF-B lowered each test virus by greater than 3-log10to non-detectable levels on all carriers in demonstration of residual antiviral activity.

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