Mobile water reuse units can be used in off-grid communities or conflict zones to provide sanitation and drinking water during times of need. In this study, a pilot-scale membrane bioreactor (MBR) - air gap membrane distillation (AGMD) system was installed in a CONEX shipping container, tested at one water reclamation facility, and subsequently transported to a second facility with different infrastructure and water quality. The MBR-AGMD treated approximately 1,000 L/day of municipal wastewater and consistently produced high-quality water with low total dissolved solids and only trace levels of organic contaminants. Non-volatile species were reduced by over 99% (2-log(10)). Total coliforms, Escherichia coli, somatic coliphages, and male-specific (F+) coliphages were reduced to levels below the limit of detection (1 Most Probable Number/100 mL) before reaching the MD system, representing reduction values of approximately 6-log(10) and 5-log(10) for bacteria and viruses, respectively. A co-spike test into the MD system was performed with >4-log(10) removals for each virus tested. At the second site, pretreatment requirements were identified, as clogging from high levels of wastewater solids challenged the MBR unit. Additional components, including an external pre-filter tank, were added to increase flexibility for wastewater streams lacking treatment by screens or primary clarification. HIGHLIGHTS center dot A membrane bioreactor-air gap membrane bioreactor (MBR-AGMD) unit was tested for decentralized potable reuse in representative settings. center dot The MBR removed carbon and nitrogen, while the AGMD polished water to potable quality. center dot Fecal indicator microbes decreased to undetectable levels by MBR and UV treatment alone. center dot AGMD added 4.4 LRV for viruses via thermal deactivation and membrane rejection. center dot Pretreatment was required when moving to a site lacking primary sedimentation.

Electronic touchscreens are common in retail food settings, though little is known about their microbial profile. In this study, electronic touchscreens were sampled in retail food establishments in four states spread across the U.S. to assess the prevalence of fecal indicators and microbes. Surface swabs of touchscreens and other high-touch surfaces (ATMs, credit card machines, restroom door handles, and employee phones; n = 175) were collected from grocery and convenience stores, and from quick service and casual dining restaurants. Heterotrophic plate counts (HPCs), coliforms, and Escherichia coli were enumerated using culture methods. Target gene sequences specific to adenoviruses, noroviruses (GI and GII), and human parainfluenza virus type 1 (HPIV-1), as well as Clostridium coccoides (human fecal bacterium) were amplified using molecular methods. Grocery and convenience stores had significantly higher HPC and coliform levels than the other food service establishment types (p < 0.05), while E. coli was not detected. Grocery store touchscreens yielded the highest level of coliforms (1.54 log10 MPN) compared to restroom door handles (0.91 log10 MPN; p < 0.05). Grocery and convenience stores demonstrated the highest detection frequency of C. coccoides, which was identified in 40.6% and 75.8% of samples, respectively. For convenience stores, 88.9% of touchscreens were positive for C. coccoides. Adenovirus was detected in 10.5% of samples, the majority corresponding to touchscreens. The detection of norovirus (GI and GII) and HPIV-1 was relatively low (1.2-1.7%). These results suggest that electronic touchscreen devices are fomite reservoirs and can become contaminated with fecal indicators and viruses during use. Knowledge gaps pertaining to the types and quantities of microbes present on these surfaces can inform future studies and risk models. Touchscreen cleaning and disinfection, plus safe hand hygiene practices after usage, are highly recommended in public settings.

As water utilities implement potable reuse technology, there is a need to understand how to increase public acceptance and trust in public water supplies. The study objective was to use surveys and interviews in a large metropolitan area in Arizona to characterize tap water and advanced purified water acceptability, and factors contributing to (un)acceptability. Participants were recruited through a water utility email listserv for participation in an online REDCap survey and/or 1-hr Zoom interview. Surveys and interviews inquired about perceptions of tap water safety, familiarity with water reuse terms, acceptability of direct potable reuse (called "advanced water purification" in our study for consistency with state messaging), and rationales related to acceptance. Four hundred seventy-nine individuals participated in the survey, and twenty-two individuals participated in the interviews, with roughly comparable demographics for our city of interest but with slightly higher levels of household income and education. Only 36 % of survey respondents use their tap water for drinking water supplies, but (42 %) would be open to drinking advanced purified water. Semi-structured interviews were conducted in 2024 on risk-based thinking to evaluate how advanced purified water may compare to current drinking water safety and analyzed with inductive thematic analysis. Survey and interview participants wanted more reassurances (e.g., third party testing and opportunities for hands-on testing). Water utilities should prioritize transparent communication strategies, including sharing detailed third-party testing data and direct community engagement initiatives, to enhance public acceptance. Utilities can build trust through clear comparisons between advanced purified water and current tap water quality.

The goal of this study was to evaluate if a magnetic water treatment device could be used to mitigate biofilms in water systems. Magnetic treatment was applied to water upstream of a modified Robbins device in which Pseudomonas fluorescence biofilms were formed. Duration of magnetic treatment, system flow rate, and field strength were varied to assess the impacts on the biofilm. A control system was concurrently established in which no magnetic treatment was applied. After treatment, the number of viable cells in the biofilm was reduced by up to 2.46 log10 CFU cm-2 depending on the operational conditions. Increased cell stress, and ultimately death, was observed during treatment as indicated by an elevated AMPi stress index. These results indicate that magnetic water treatment may be an effective technology to decrease the extent of biofilms in water systems and a reduced need for chemical treatment. A mechanism is proposed in which metabolic processes are hindered due to the magnetic field effects on ions in the water. However, a mechanistic investigation remains outside the scope of this study. Future studies should aim to characterize both the impacts of treatment on the matrix and cellular processes to determine a mechanism for the observed effects.

Wastewater treatment plants (WWTPs) provide vital services to the public by removing contaminants from wastewater prior to environmental discharge or reuse for beneficial purposes. WWTP workers occupationally exposed to wastewater can be at risk of respiratory or gastrointestinal diseases. The study objectives were to: (1) quantify pathogens and pathogen indicators in wastewater aerosols near different WWTP processes/unit operations, (2) develop a QMRA model for multi-pathogen and multi-exposure pathway risks, and (3) create a webbased application to perform and communicate risk calculations for wastewater workers. Case studies for seven different WWTP job tasks were performed investigating infection risk across nine different enteric and respiratory pathogens. It was observed that the ingestion risk among job tasks was highest for "walking the WWTP," which involved exposure from splashing, bioaerosols, and hand-to-mouth contact from touching contaminated surfaces. There was also a notable difference in exposure risk during peak (5:00am-9:00am) and non-peak hours (9:00am- 5:00am), with risks during the peak flow hours of the early morning assumed to be 5 times greater than non-peak hours. N95 respirator usage reduced median respiratory risks by 77 %. The developed tool performs multiple QMRA calculations to estimate WWTP workers' infection risks from accidental ingestion or inhalation of wastewater from multiple pathogens and exposure scenarios, which can inform risk management strategies to protect occupational health. However, more data are needed to reduce uncertainty in model estimates, including comparative data for pathogen concentrations in wastewater during peak and non-peak hours. QMRA tools will increase accessibility of risk models for utilization in decision-making.

The ongoing pandemic of Coronavirus disease 2019 (COVID-19) has affected >600 million people with >6 million deaths. Although Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2), the etiologic agent of COVID-19, is transmitted via respiratory droplets or direct contact, isolation of viable SARS-CoV-2 in feces has been reported. Therefore, there is a need for understanding the persistence of SARS-CoV-2 and emerging variants in wastewater. In this study, the survival of SARS-CoV-2 isolate hCoV-19/USA-WA1/2020 was observed in three wastewater matrices - filtered and unfiltered raw wastewater, and secondary effluent. All experiments were conducted within a BSL-3 laboratory at room temperature. The time required for inactivation of 90 % (T90) of SARS-CoV-2 was 10.4, 10.8, and 18.3 h for unfiltered raw, filtered raw, and secondary effluent, respectively. Progressive decline in infectivity of the virus following first order kinetics was noted in these wastewater matrices. To the best of our knowledge, this is the first study to describe the survival of SARS-CoV-2 in secondary effluent.

Microfiltration (MF) has been widely adopted as an advanced treatment process to reduce suspended solids and turbidity in treated wastewater effluents designated for potable reuse. Although microfilter pores are much larger than viruses, the addition of a coagulant upstream of a microfilter system can achieve stable virus removal. Ceramic membranes have a narrow pore size distribution to achieve the high removal of contaminants. This study aims to evaluate virus log reduction using bench-scale coagulation and ceramic membrane MF. To investigate the effects of differences in net surface hydrophobicity, 18 sewage-derived F-specific RNA phages (FRNAPHs) were used for batch hydrophobicity and coagulation-MF tests. The capability of bench-scale coagulation and ceramic membrane MF under continuous automated long-term operation was tested to remove the lab reference strain MS2 and three selected FRNAPH isolates which varied by surface property. Median virus log reduction values (LRVs) exceeding 6.2 were obtained for all three isolates and MS2. Although coagulation and hydrophobicity were positively correlated, the virus isolate demonstrating the lowest level of hydrophobicity and coagulation (genogroup I) still exhibited a high LRV. Thus, coagulation and ceramic membrane MF systems may serve as viable options for virus removal during water reclamation and advanced treatment.

Membrane distillation (MD) is a thermally-driven process that can treat high concentration streams and provide a dual barrier for rejection and reduction of pathogens. Thus, MD has potential applications in treating concen-trated wastewater brines for enhancing water recovery and potable water reuse. In bench-scale studies, it was demonstrated that MD can provide high rejection of MS2 and PhiX174 bacteriophage viruses, and when oper-ating at temperatures greater than 55 degrees C, can reduce virus levels in the concentrate. However, bench-scale MD results cannot directly be used to predict pilot-scale contaminant rejection and removal of viruses because of the lower water flux and higher transmembrane hydraulic pressure difference in pilot-scale systems. Thus far, virus rejection and removal have not been quantified in pilot-scale MD systems. In this work, the rejection of MS2 and PhiX174 at low (40 degrees C) and high (70 degrees C) inlet temperatures is quantified in a pilot-scale air-gap MD system using tertiary treated wastewater. Both viruses were detected in the distillate which suggests the presence of pore flow; the virus rejection at a hot inlet temperature of 40 degrees C for MS2 and PhiX174 were 1.6-log10 and 3.1-log10, respectively. At 70 degrees C, virus concentrations in the brine decreased and were below the detection limit (1 PFU per 100 mL) after 4.5 h, however, viruses were also detected in the distillate in that duration. Results demonstrate that virus rejection is lower in pilot-scale experiments because of increased pore flow that is not captured in bench-scale experiments.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is present in both respiratory secretions and feces, creating its potential for transmission by swimming pools. Recreational water activity is known to be at increased risk of respiratory infections and respiratory viruses have caused been detected and have caused outbreaks in swimming pools. However, little is known regarding the chlorine inactivation of SARS-CoV-2 in water typical of swimming pools in the USA. In this study, the inactivation of SARS-CoV-2 Isolate hCoV-19/USA-WA1/2020 was observed in water by chlorination. All experiments were conducted within a BSL-3 laboratory at room temperature. Our results show that the virus was reduced by 3.5 log (> 99.9%) after 30 s of 2.05-mg/L free chlorine contact and greater than 4.17 log (limit of detection) (> 99.99%) within 2 min.

Concerns of fecal-aerosol transmission of coronavirus disease 2019 (COVID-2019) coupled with increased transmissibility and disease severity of Delta and Omicron variants of concern (VOC) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), suggest studies on survival of VOC in wastewater are warranted. To the best of our knowledge, this is the first study to investigate the survivability of Delta and Omicron VOC in filtered and unfiltered raw wastewater, and secondary effluent at room temperature (23 °C). The time required for 90 % inactivation (T90) of Delta and Omicron VOC in unfiltered raw wastewater was calculated as 17.7 and 15.3 h, respectively. Rapid inactivation of VOC in wastewater and inability to isolate SARS-CoV-2 in wastewater suggest risks from fecal-aerosol transmission are low. Nevertheless, high transmissibility of VOC cautions overruling fecal-aerosol transmission of COVID-19. Future studies on survival of SARS-CoV-2 in wastewater should attempt viral culture by spiking feces collected from COVID-19 infected patients into wastewater to match the real-world scenario.

Background: Hand hygiene is critical to lower the potential for the spread of SARS-CoV-2 and other infectious agents by direct contact. When running water and soap are not available for hand hygiene, ethanol-based hand sanitizers are currently the recommended standard of care [1e3]. Though recently published data showed comparable in vitro effectiveness of benzalkonium chloride (BAK)-based and ethanol-based hand sanitizers against SARS-CoV-2 virus, a paucity of peer-reviewed data on the effectiveness of these formulations against other types of infective coronaviruses remains. This work assessed human coronavirus HCoV-229E (genus Alphacoronavirus) concurrently with SARS-CoV-2, Isolate USA-WA1/2020 (genus Betacoronavirus) to fill this gap.Methods: The test was conducted according to EN14476:2013-A2:2019 [EN14476] Quan-titative Suspension Test for the Evaluation of Virucidal Activity in the Medical Area [4]. Two BAK-based hand sanitizers, five ethanol-based hand sanitizers, and an 80% ethanol reference formulation were tested for antiviral activity against SARS-CoV-2 and HCoV-229E at 15-and 30-second contact times.Results: Both SARS-CoV-2 and HCoV-229E were reduced by greater than 4.00-log10 within 15 seconds of contact. Virus decay constants (k) following first-order kinetics were similar for BAK and ethanol-based formulations against both test viruses. The SARS-CoV-2 results reported herein mirrored previous data reported by Herdt et al. (2021). Conclusion: BAK and ethanol hand sanitizer formulations inactivate SARS-CoV-2 and HCoV-229E at similar rates. This data supports previously published effectiveness data for both chemistries and indicates that additional coronavirus strains and variants would demon-strate similar inactivation trends.& COPY; 2023 The Authors. Published by Elsevier Ltd on behalf of The Healthcare Infection Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Membrane distillation (MD) is a desalination technology with promising applications in treating brines generated by reverse osmosis. Theoretically, MD can achieve 100% rejection of non-volatile contaminants such as organic and inorganic solutes and pathogens because only the vapor phase permeates through the membrane. However, polymeric membranes are subject to a wide distribution of pore sizes that may result in pore flow or liquid flux through even a new membrane resulting in poor contaminant rejection. In pilot-scale MD systems, a larger membrane area increases the hydraulic pressure in the flow channel and the transmembrane hydraulic pressure difference, thus increasing the probability of pore flow of non-volatile contaminants through the membrane and providing enhanced resolution of contaminant detection. This work reports membrane rejection of organic and inorganic non-volatile solutes in a pilot-scale air-gap MD (AGMD) element and quantifies, for the first time, transport of non-volatile solutes through the membrane because of pore flow. Pathogen rejection in the pilotscale MD system was also measured using enteric virus surrogates MS2 and PhiX174 as tracers. Organic and inorganic solutes and both viruses were detected in the distillate, suggesting the presence of pore flow. No difference between organic and inorganic solute rejection was observed, and both decreased (from 2.5-log10 to 1.5-log10) with an increase in air-gap vacuum (from 50 to 500 mbar). At 50 mbar and low evaporator inlet temperature (40 degrees C), virus rejection (2.4 -log10) was higher than organic and inorganic solute rejection (1.7log10).

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 log 10 reductions of 1.62, 3.33, and 0.92, respectively. Formulation TF-B lowered each test virus by greater than 3-log 10 to non-detectable levels on all carriers in demonstration of residual antiviral activity.

Propolis is a resinous substance collected by bees (Apis mellifera). It is used for its biological properties. This natural product is available as a safe therapeutic option. Herein, we report the antiviral effects of brown propolis extract from Mexico and green and red propolis extracts from Brazil, as well as their phenolic compounds (quercetin, caffeic acid, and rutin) in preventing infection of MRC-5 cells by HCoV-229E. Normal human fibroblast lung cells (MRC-5) were used to determine the cytotoxicity of the compounds. All samples studied showed antiviral activity. Green and brown propolis extracts, and quercetin exhibited the best EC50 values with values of 19.080, 11.240, and 77.208 mu g/mL against HCoV-229E, respectively, and with TC50 of 62.19, 29.192, and 298 mu g/mL on MRC-5 cells, respectively. These results are the first in vitro study of the effects of propolis on HCoV-229E and provide the basis for the development of natural formulations against other coronavirus strains.

Antimicrobial surfaces and coatings have been available for many decades and have largely been designed to kill or prevent the growth of bacteria and fungi. Antiviral coatings have become of particular interest more recently during the COVID-19 pandemic as they are designed to act as continuously active disinfectants. The most studied antiviral coatings have been metal-based or are comprised of silane quaternary ammonium formulations. Copper and silver interact directly with proteins and nucleic acids, and influence the production of reactive free radicals. Titanium dioxide acts as a photocatalyst in the presence of water and oxygen to produce free radicals in the presence of UV light or visible light when alloyed with copper or silver. Silane quaternary ammonium formulations can be applied to surfaces using sprays or wipes, and are particularly effective against enveloped viruses. Continuously active disinfectants offer an extra barrier against fomite-mediated transmission of respiratory and enteric viruses to reduce exposure between routine disinfection and cleaning events. To take advantage of this technology, testing methods need to be standardized and the benefits quantified in terms of reduction of virus transmission.

Germicidal ultraviolet (UV) devices have been widely used for pathogen disinfection in water, air, and on food and surfaces. Emerging UV technologies, like the krypton chloride (KrCl*) excimer emitting at 222 nm, are rapidly gaining popularity due to their minimal adverse effects on skin and eyes compared with conventional UV lamps emitting at 254 nm, opening opportunities for UV disinfection in occupied public spaces. In this study, inactivation of seven bacteria and five viruses, including waterborne, foodborne and respiratory pathogens, was determined in a thin‐film aqueous solution using a filtered KrCl* excimer emitting primarily at 222 nm. Our results show that the KrCl* excimer can effectively inactivate all tested bacteria and viruses, with most microorganisms achieving more than 4‐log (99.99%) reduction with a UV dose of 10 mJ cm−2. Compared with conventional UV lamps, the KrCl* excimer lamp exhibited better disinfection performance for viruses but was slightly less effective for bacteria. The relationships between UV sensitivities at 222 and 254 nm for bacteria and viruses were evaluated using regression analysis, resulting in factors that could be used to estimate the KrCl* excimer disinfection performance from well‐documented UV kinetics using conventional 254 nm UV lamps. This study provides fundamental information for pathogen disinfection when employing KrCl* excimers.

Chlorination is the most common form of water disinfection for recreational swimming pools and represents a major cost for many large-scale operations. Reducing the chlorine demand in a system may alleviate these costs by decreasing the amount of chlorine required to maintain a target disinfection residual. While magnetic water treatment is common for removal of pipe scale, impacts on chlorine demand have not been evaluated. The application of a commercial magnetic treatment device significantly (p < 0.05) reduced the chlorine demand by 13.8 % within 24 h, due to a reduction of monochloramine (NH2Cl), when applied to a simulated pool system. Subsequent breakpoint chlorination through the addition of calcium hypochlorite (CaOCl2) resulted in a 30.8 % increase in free chlorine concentration. Additionally, a 1-h exposure to the magnetic field resulted in a 6.1 % reduction in monochloramine compared to the control, demonstrating that transient flow-through treatment can yield a reduced yet still significant effect. Mechanistically this effect could be due to the magnetic field effects (MFE) influencing the electron configuration of compounds in the system, thus altering reaction equilibria to favor more volatile chloramine species. This treatment is potentially a cost-effective method to improve the efficiency of chlorination via the demonstrated reduction of chlorine demand.

Respiratory viruses can be transmitted by fomite contact, but no data currently exist on the transfer of enveloped viruses. The transfer efficiency of human coronavirus from various hard surfaces ranged from 0.46% to 49.0%. This information can be used to model the fomite transmission of enveloped viruses.

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-log10 for MS2 and PhiX174 and more than 3-log10 for HCoV-229E. Also, membrane rejection was greater than 6-log10 for MS2 and PhiX174 and greater than 2.5-log10 for HCoV-229E.