Water scarcity is an escalating global challenge driven by population growth and resource depletion. Conventional fresh water production methods typically require access to liquid water sources, limiting their applicability in remote or arid regions. Water-from-air technologies offer a potential solution but are often hindered by high energy demands and/or climatological conditions. This study introduces clathrate-based desalination of deliquescent salt solutions as a novel approach for atmospheric water harvesting, with potassium acetate selected as the model salt. Potassium acetate deliquesces at a relative humidity as low as 23.3%, producing a concentrated saline solution (17.8 wt% at 90% RH). By exploiting the clathrate creeping phenomenon, where hydrates grow along surfaces, enabling facilitated phase separation, 84% purification of this brine was achieved. Advanced architectures, further enhancing the crucial clathrate creeping potentially lead to further improvements of the obtained results. This process demonstrates the potential of an energy-efficient alternative to existing water-from-air technologies.

As more data on virus concentrations in influent water from wastewater treatment plants (WWTPs) becomes available, establishing best practices for virus measurements, monitoring, and statistical modelling can improve the understanding of virus concentration distributions in wastewater. To support this, we assessed the temporal variability of norovirus, adenovirus, enterovirus, and rotavirus concentrations in influent water across multiple WWTPs in Switzerland, the USA, and Japan. Our findings demonstrate that the lognormal distribution accurately describes temporal variations in concentrations for all viruses at all sites, outperforming the gamma and Weibull distributions, which fail to capture high variability. However, notable differences in variability and uncertainty were observed across systems, underscoring the need for site-specific assessments. Using lognormal parameters, we identified optimal monitoring frequencies that balance cost-effectiveness and precision. For most sites, weekly monitoring was sufficient to estimate the annual average concentration of enteric viruses within a 95% confidence interval of 0.5 log. We further examined the mechanistic basis of the lognormal distribution, highlighting processes that drive its prevalence and shape the behavior of its upper tail. By integrating these insights, this study provides a statistical foundation for optimizing virus monitoring frameworks and informing public health interventions targeting wastewater systems.

This study aimed to investigate the removal efficiency of (psycho)pharmaceuticals by ozonation and granular active carbon (GAC) in wastewater effluent, using risk as the metric for adequate removal instead of aqueous concentrations. Conventionally treated effluent was further treated with ozone or GAC until there was a 25% reduced UVA absorbance, to allow for a direct comparison of the two treatment types. Samples were analysed using Ultra High-Performance Liquid Chromatography-Quadrupole Time of Flight-High Resolution Mass Spectrometry (UHPLC-qTOF-HRMS), where 20 (psycho)pharmaceuticals were quantified, and their risk was assessed using Predicted No Effect Concentrations (PNECs). A further assessment was performed using Quantitative Structural Activity Relationships (QSARs) for both parent compounds and their Oxidation Transformation Products (OTPs) to compare the relative toxicity of new species being formed by the ozone treatment. The total median removal efficiency across all compounds was 60 ± 3% for ozone in terms of concentration, yielding a 73 ± 2% reduction in terms of risk for the parent compounds, while the median removal efficiency for GAC is 57 ± 9% as expressed in concentration, and 46 ± 11% in terms of risk reduction. When factoring in the OTP toxicity, the median risk reduction for ozone flips to -274 ± 124%, indicating that there may be an increase in risk during ozonation. Pearson correlations on molecular descriptors indicated that ozone removal most strongly correlated with the number of activated aromatic rings ( = 0.65), while for GAC the topological polar surface area correlated strongest with removal ( = 0.54), therefore indicating that ozone and GAC target different types of molecules. The study demonstrates the merits of a risk-driven approach over concentration-based removal targets in current legislation, but also highlighted some drawbacks, especially with regards to data gaps and model accuracies.

Quantification of copies of double stranded RNA using RT-PCR methods may require denaturation of the double stranded structure using an initial high temperature incubation followed by rapid cooling, herein called "heat snap". Papers in the literature that report rotavirus RNA concentrations in fecal and environmental samples do not consistently report the use of such a "heat snap". In this study, we quantified rotavirus RNA in diverse environmental samples (wastewater solids, wastewater, and drainage samples) using digital RT-PCR methods with and without a heatsnap. Concentrations were higher in samples by a factor of 125 when a heat snap was applied. This was consistent across sample types, and across laboratories and PCR instrumentation. We recommend a heat snap be used when enumerating double stranded RNA from rotavirus and other double stranded RNA viruses in environmental samples.

-Nitrosodimethylamine (NDMA) is a probable human carcinogen that can be formed in drinking water treatment systems as a byproduct of chloramination and chlorination. Occurrence of NDMA and other -nitrosamines in the United States has been previously assessed using a variety of techniques, but few studies have been able to distinguish between concentrations above and below suggested screening levels (, 0.7 ng L for NDMA). This study evaluated the presence of NDMA and seven other -nitrosamines in two drinking water distribution systems in the northeastern United States ( = 42 locations) and assessed factors influencing its occurrence. NDMA was present in 98% of water samples across both systems (MDL 0.15 ng L) with higher concentrations in the system utilizing chloramination (0.39-1.32 ng L) than the system utilizing chlorination (0.20-0.54 ng L). Samples were collected before and after flushing taps, and higher concentrations of NDMA were observed in samples collected prior to flushing, suggesting increased formation due to temporary stagnation. -Nitrosomorpholine was the only other -nitrosamine detected in samples taken after tap flushing (5% detection rate; MDL 0.21 ng L), though four additional nitrosamines were detected before flushing in at least one sample. Water quality parameters (, chlorine residual, dissolved organic carbon, total dissolved nitrogen, specific UV absorbance, pH, temperature, specific conductance) and other disinfection byproducts (trihalomethanes) were measured to assess correlations with NDMA occurrence, and NDMA concentrations were negatively correlated with residual chlorine in both distribution systems. These observations illustrate the potential prevalence of low-level nitrosamine occurrence in disinfected drinking water and provide a framework for system-specific understanding of NDMA occurrence, which can aid in prioritizing locations where further investigation may be needed to mitigate potential exposure risks.

Water resource recovery facilities (WRRFs) are sinks of legacy and replacement per- and polyfluoroalkyl substances (PFAS). This study evaluates the potential biotransformation, bioaccumulation, and adsorption of PFAS in wastewater sludge. Individual partitioning of parent PFAS and transformation products were measured in aqueous and solid phases of aerobic and anaerobic bacterial cultures for five structurally variable legacy and replacement PFAS using independent tests: perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorobutane sulfonic acid (PFBS), 6:2 fluorotelomer sulfonate (6:2 FTS), and hexafluoropropylene oxide dimer acid (GenX). Anaerobic cultures (anaerobic digestate and dehalogenating KB-1®) showed only adsorption (10.9-38.3%) with no transformation of the parent PFAS, irrespective of structural variances, in 90 days. Aerobic cultures from activated and nitrification sludge resulted in adsorption (26.9 ± 1.2-55.8 ± 1.4%), biotic accumulation (13.35-17.55%), and transformation (28.96-47.87%) of long-chain PFAS in 21 days. Notably, PFOA, PFOS, and 6:2 FTS were rapidly transformed 47.87 ± 1.6%, 28.96 ± 0.6%, and 43.1 ± 1.0%, respectively, after a shift occurred in microbial community structure under batch growth after 6 days, with the generation of shorter-chain compounds (carboxylates and sulfonates) and limited defluorination. Aerobic wastewater microbial communities converged, with , , , , , and positively correlated with PFAS degradation. This study highlights the importance of unit processes and microbial community structure in controlling the fate and transport of select PFAS.

Psychopharmaceuticals are an emerging group of hazardous contaminants that pose a risk to the aquatic environment. Yet, modern wastewater treatment plants (WWTPs) do not remove them sufficiently to alleviate these risks. The present study aimed therefore to explore the effectiveness of an alternative nature-based tertiary treatment of WWTP effluent to remove psychopharmaceuticals. To this end, an algae-mussel trophic cascade setup was designed in which algae were grown in effluent over the course of 11 days and subsequently fed to mussels for a further 3 days. Removal of 30 psychopharmaceuticals for each of the treatments (algae, mussels, algae + mussels) was calculated relative to control samples, and removal efficiency was contextualised by performing an indicative risk assessment. Twelve psychopharmaceuticals were quantified during the experiment, with 11 encountered in all treatments. The compounds fell into 3 categories: positive removal (citalopram, lamotrigine, and venlafaxine), negative removal (carbamazepine, gabapentin, and pregabalin), and no significant changes in concentration (amitriptyline, quetiapine, tramadol, fluvoxamine, lidocaine, and ibuprofen). Both positive and negative removals were largely driven by the presence of the algae rather than that of the mussels. Compounds with a low p showed negative removal due to the algal growth induced rise in pH, which was not negated by the mussels at the end of the cascade. Ibuprofen was not removed by any treatment and was also the only compound that represented a substantial risk. The cumulative risks indicated that the algal-mussel cascade actually increased the risk due to the negative removal of compounds present in high concentrations such as carbamazepine. Pregabalin and gabapentin also increased in risk, but did, however, not significantly change the overall risk from the analysed compounds due to their low concentrations. Since the presently designed nature-based treatment could not negate risk, it is not suitable for the removal of psychopharmaceuticals.

The persistence of pharmaceuticals and personal care products (PPCPs) through wastewater treatment and resulting contamination of aquatic environments and drinking water is a pervasive concern, necessitating means of identifying effective treatment strategies for PPCP removal. In this study, we employed machine learning (ML) models to classify 149 PPCPs based on their chemical properties and predict their removal wastewater and water reuse treatment trains. We evaluated two distinct clustering approaches: C1 (clustering based on the most efficient individual treatment process) and C2 (clustering based on the removal pattern of PPCPs across treatments). For this, we grouped PPCPs based on their relative abundances by comparing peak areas measured non-target profiling using ultra-performance liquid chromatography-tandem mass spectrometry through two field-scale treatment trains. The resulting clusters were then classified using Abraham descriptors and log  as input to the three ML models: support vector machines (SVM), logistic regression, and random forest (RF). SVM achieved the highest accuracy, 79.1%, in predicting PPCP removal. Notably, a 58-75% overlap was observed between the ML clusters of PPCPs and the Abraham descriptor and log  clusters of PPCPs, indicating the potential of using Abraham descriptors and log  to predict the fate of PPCPs through various treatment trains. Given the myriad of PPCPs of concern, this approach can supplement information gathered from experimental testing to help optimize the design of wastewater and water reuse treatment trains for PPCP removal.

This study develops quantifiable metrics to describe the resilience of Water Resource Recovery Facilities (WRRFs) under extreme stress events, including those posed by long-term challenges such as climate change and population growth. Resilience is the ability of the WRRFs to withstand adverse events while maintaining compliance or an operational level of service. Existing studies lack standardised resilience measurement methods. In this paper, we propose a resilience metric based on signal temporal logic (STL) to describe acceptable functionality of the WRRFs ( meeting regulatory limits). By using Monte Carlo simulations and scenario optimisation on a model of a WRRF, we determine the maximum stress the WRRF can handle while meeting STL constraints for biochemical oxygen demand (BOD) and chemical oxygen demand (COD) compliance limits. The results are applied to a simple digital model of a facility with 22 components. Importantly, this method can be applied to data that water companies routinely and regularly monitor, and could be incorporated into SCADA systems. In our case studies, we determine threshold stressor values of extreme rainfall that result in a loss of resilience. Our results offer insights into the design of more resilient treatment processes to reduce environmental impacts.

Sub-city, or sub-sewershed, wastewater monitoring for infectious diseases offers a data-driven strategy to inform local public health response and complements city-wide data from centralized wastewater treatment plants. Developing strategies for equitable representation of diverse populations in sub-city wastewater sampling frameworks is complicated by misalignment between demographic data and sampling zones. We address this challenge by: (1) developing a geospatial analysis tool that probabilistically assigns demographic data for subgroups aggregated by race and age from census blocks to sub-city sampling zones; (2) evaluating representativeness of subgroup populations for COVID-19 wastewater-based disease surveillance in Davis, California; and (3) demonstrating scenario planning that prioritizes vulnerable populations. We monitored SARS-CoV-2 in wastewater as a proxy for COVID-19 incidence in Davis (November 2021-September 2022). Daily city-wide sampling and thrice-weekly sub-city sampling from 16 maintenance holes covered nearly the entire city population. Sub-city wastewater data, aggregated as a population-weighted mean, correlated strongly with centralized treatment plant data (Spearman's correlation 0.909). Probabilistic assignment of demographic data can inform decisions when adapting sampling locations to prioritize vulnerable groups. We considered four scenarios that reduced the number of sampling zones from baseline by 25% and 50%, chosen randomly or to prioritize coverage of >65-year-old populations. Prioritizing representation increased coverage of >65-year-olds from 51.1% to 67.2% when removing half the zones, while increasing coverage of Black or African American populations from 67.5% to 76.7%. Downscaling had little effect on correlations between sub-city and centralized data (Spearman's correlations ranged from 0.875 to 0.917), with strongest correlations observed when prioritizing coverage of >65-year-old populations.

Exposure to fecally contaminated drinking water contributes to the global disease burden, especially in sub-Saharan Africa (SSA). We used cross-sectional data and elimination regression analysis to examine factors influencing contamination in household drinking water samples from 4,499 rural households in nine countries in SSA (Malawi, Mozambique, and Zambia in Southern Africa; Ghana, Mali, and Niger in Western Africa; and Kenya, Rwanda, and Tanzania in Eastern Africa). The proportion of household water samples containing was 71%, ranging from 45% (Malawi) to 89% (Tanzania). Pooled and multi-country predictive logistic regression models showed that using an unimproved-type water source, the absence of a community water committee, and domestic animal ownership were significantly associated with household drinking water contamination. Household water treatment and storage practices, sanitation and hygiene practices, and payment for drinking water were not significantly associated with contamination in any model. The season was a significant predictor of in the pooled model; samples collected in the rainy season were 2.3 [2.0, 2.7] times as likely to be contaminated with . Practitioners and policymakers should prioritize implementing piped on-plot water services, establishing effective local water source management structures, and incorporating animal husbandry practices into water, sanitation, and hygiene interventions.

Premise plumbing water quality degradation has led to negative health impacts from pathogen outbreaks (e.g., and non-tuberculous mycobacteria), as well as chronic effects from exposure to heavy metals or disinfection by-products (DBP). Common water quality management interventions include flushing, heat shock (thermal disinfection), supplemental disinfection (shock or super chlorination), and water heater temperature setpoint change. In this study, a - colonized Leadership in Energy and Environmental Design (LEED) certified building was monitored to study health-relevant water quality changes before and after three controlled management interventions: (1) flushing at several points throughout the building; (2) changing the water heater set point; and (3) a combination of interventions (1) and (2) by flushing during a period of elevated water heater set point (incompletely performed due to operational issues). Microbial (culturable the gene, and cATP) and physico-chemical (pH, temperature, conductivity, disinfectant residual, disinfection by-products (DBPs; total trihalomethanes, TTHM), and heavy metals) water quality were monitored alongside building occupancy as approximated using Wi-Fi logins. Flushing alone resulted in a significant decrease in cATP and concentrations ( = 0.018 and 0.019, respectively) and a significant increase in chlorine concentrations ( = 0.002) as well as iron and DBP levels ( = 0.002). Copper concentrations increased during the water heater temperature setpoint increase alone to 140°F during December 2022 ( = 0.01). During the flushing and elevated temperature in parts of the building in February 2023, there was a significant increase in chlorine concentrations ( = 0.002) and iron ( = 0.002) but no significant decrease in concentrations in the drinking water samples ( = 0.27). This study demonstrated the potential impacts of short term or incompletely implemented interventions which in this case were not sufficient to holistically improve water quality. As implementing interventions is logistically- and time-intensive, more effective and holistic approaches are needed for informing preventative and corrective actions that are beneficial for multiple water quality and sustainability goals.

Orthophosphate (PO) is a commonly used corrosion control treatment to reduce lead (Pb) concentrations in drinking water. PO reduces Pb concentrations by forming relatively insoluble lead phosphate (Pb-PO) minerals. In some cases, however, Pb-PO minerals have been observed to form nanoparticles, and if suspended in water, these nanoparticles can be mobile and reach consumer taps. Although recent research on Pb-PO particles has been performed, there remains a need to improve our understanding of the nature of Pb-PO nanoparticles. For that reason, Pb precipitation experiments were conducted to generate Pb-PO nanoparticles in bench scale studies for analysis. The study objective was to observe how pH, dissolved inorganic carbon (DIC), and PO impacted the properties of Pb-PO particles. Specifically, particle size, surface charge, mineralogy, and solubility were analysed. Hydrocerussite was precipitated when no PO was present, hydroxypyromorphite (Pb(PO)OH) nanoparticles (<100 nm diameter) were precipitated when excess PO relative to Pb necessary to completely precipitate the mineral was present, and a mixture of the two minerals was precipitated when an insufficient amount of PO was present. Hydroxypyromorphite particles were less soluble than hydrocerussite by up to two orders of magnitude. The estimated of 10 in this work closely aligned with previous estimates that ranged from 10 to 10. Hydroxypyromorphite particles would not settle in water which was likely due to their small size and high negative charge. The mobility and size of these particles indicates that there are potential implications for such particulate Pb to remain suspended in water and thus be present in the tap water.

Selenium (Se) is an essential micronutrient for many living organisms particularly due to its unique redox properties. We recently found that the sulfur (S) analog for dimethyl selenide (DMSe), dimethyl sulfide (DMS), reacts fast with the marine oxidant hypobromous acid (HOBr) which likely serves as a sink of marine DMS. Here we investigated the reactivity of HOBr with dimethyl selenide and dimethyl diselenide (DMDSe), which are the main volatile Se compounds biogenically produced in marine waters. In addition, the reactivity of HOBr with further organic Se compounds was tested, , SeMet (as -acetylated-SeMet), and selenocystine (SeCys as -acetylated-SeCys), as well as the phenyl-analogs of DMSe and DMDSe, respectively, diphenyl selenide (DPSe) and diphenyl diselenide (DPDSe). Apparent second-order rate constants at pH 8 for the reactions of HOBr with the studied Se compounds were (7.1 ± 0.7) × 10 M s for DMSe, (4.3 ± 0.4) × 10 M s for DMDSe, (2.8 ± 0.3) × 10 M s for SeMet, (3.8 ± 0.2) × 10 M s for SeCys, (3.5 ± 0.1) × 10 M s for DPSe, and (8.0 ± 0.4) × 10 M s for DPDSe, indicating a very high reactivity of all selected Se compounds with HOBr. The reactivity between HOBr and DMSe is lower than for DMS and therefore this reaction is likely not relevant for marine DMSe abatement. However, the high reactivity of SeMet with HOBr suggests that SeMet may act as a relevant quencher of HOBr.

Electrochemical wastewater treatment is a promising technique to remove recalcitrant pollutants from wastewater. However, the complexity of elucidating the underlying degradation mechanisms hinders its optimisation not only from a techno-economic perspective, as it is desirable to maximise removal efficiencies at low energy and chemical requirements, but also in environmental terms, as the generation of toxic by-products is an ongoing challenge. In this work, we propose a novel combined experimental and computational approach to (i) estimate the contribution of radical and non-radical mechanisms as well as their synergistic effects during electrochemical oxidation and (ii) identify the optimal conditions that promote specific degradation pathways. As a case study, the distribution of the degradation mechanisms involved in the removal of benzoic acid (BA) boron-doped diamond (BDD) anodes was elucidated and analysed as a function of several operating parameters, , the initial sulfate and nitrate content of the wastewater and the current applied. Subsequently, a multivariate optimisation study was conducted, where the influence of the electrode nature was investigated for two commercial BDD electrodes and a customised silver-decorated BDD electrode. Optimal conditions were identified for each degradation mechanism as well as for the overall BA degradation rate constant. BDD selection was found to be the most influential factor favouring any mechanism (, 52-85% contribution), given that properties such as its boron doping and the presence of electrodeposited silver could dramatically affect the reactions taking place. In particular, decorating the BDD surface with silver microparticles significantly enhanced BA degradation sulfate radicals, whereas direct oxidation, reactive oxygen species and radical synergistic effects were promoted when using a commercial BDD material with higher boron content and on a silicon substrate. Consequently, by simplifying the identification and quantification of underlying mechanisms, our approach facilitates the elucidation of the most suitable degradation route for a given electrochemical wastewater treatment together with its optimal operating conditions.

Onsite non-potable water reuse systems (ONWS) are decentralized systems that treat and repurpose locally collected waters ( greywater or combined wastewater) for uses such as irrigation and flushing toilets. To ensure that treatment is meeting risk benchmarks, it is necessary to monitor the efficacy of pathogen removal. However, accurate assessment of pathogen reduction is hampered by their sporadic and low occurrence rates in source waters and concentrations in treated water that are generally below measurement detection limits. An alternative metric for evaluation of onsite water treatment is log reduction of a more abundant organism that can serve as a surrogate for the pathogen removal. Viruses endogenous to the decentralized system could serve as monitoring surrogates to verify that treatment meets the relevant viral log reduction targets. This study assesses eight candidate PCR targets representing potential monitoring surrogates from different viral classes to determine whether they could be used to verify the efficacy of treatment in onsite non-potable water reuse systems. Candidates tested include markers for (formerly CrAssphage), Pepper Mild Mottle Virus (PMMoV), Microviridae, and T4 Coliphage. We quantified these targets in untreated influent wastewater at three onsite non-potable water reuse systems, two that use greywater and one that uses combined wastewater. We also confirmed, using amplicon sequencing, that the widely used and PMMoV primers correctly target their respective regions of interest, and found sequence diversity within the amplicons including in the probe binding region. Ultimately, we found that the surrogates assessed are not abundant enough for end uses with higher exposure use and concomitant greater removal requirements (, indoor non-potable uses), but may be effective for end uses where exposure risk is lower (, irrigation).

This study characterized (BG) as a Sterne (BAS) surrogate for wastewater treatment-related studies of UV inactivation, adsorption onto powdered activated carbon (PAC), and bioaerosol emission. The inactivation of BG was faster than that of BAS in DI water (pseudo first-order rate constants of 0.065 and 0.016 min respectively) and in PBS solution (0.030 and 0.005 min respectively). BG was also removed more quickly than BAS by PAC adsorption in DI (0.07 and 0.05 min respectively) and in PBS (0.09 and 0.04 min respectively). In DI, BG aggregated more ( < 0.05) than BAS when the pH was 7 or greater but there were no statistically significant differences in NaCl solution. Spore aggregation was also studied with extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) models. Less than 1% of all spores were released as bioaerosols, and there was no significant difference ( > 0.05) in emission between BG and BAS. To the author's knowledge, this study is the first to demonstrate that BG is a suitable surrogate for BAS for bioaerosol emissions, but a poor surrogate for both UV inactivation and PAC adsorption. These results can be used to understand the ability of BAS to act as a surrogate for BA Ames because of its genetic and morphological similarities with BAS.

Bioelectrochemical systems (BESs) such as microbial fuel cells (MFCs) present numerous benefits for the removal and recovery of heavy metals from industrial and municipal wastewater. This study evaluated the life cycle environmental impact of simultaneous hexavalent chromium (Cr(vi)) removal and bioelectricity generation in a dual chamber MFC. Results indicate a global warming potential (GWP) of -0.44 kg carbon dioxide (CO)-eq. per kg of chromium recovered, representing a total saving of up to 97% in comparison with existing technologies for the treatment of Cr(vi) laden wastewater. The observed savings in GWP (kg CO-eq.) reduced to 61.8% with the removal of the allocated credits from the MFC system's life cycle. Of all the various sub-systems considered within the chromium waste treatment plant, the MFC unit and the chromium metal recovery unit had the largest impact in terms of GWP (kg CO-eq.), non-renewable energy use (NREU) (MJ primary), and mineral extraction (MJ surplus). A statistical analysis of the results showed that an increase in chemical oxygen demand (COD) was associated with a reduction in GWP (kg CO-eq.), NREU (MJ primary), and terrestrial ecotoxicity (kg triethylene glycol equivalents into soil (TEG soil)-eq.). The life cycle assessment (LCA) output showed a high sensitivity to changes in the materials and construction processes of MFC reactors, indicating the need for further research into sustainable materials for MFC reactor construction. The observed interaction effects of process variables also suggest the need for combined optimization of these variables. Analysis with other types of metals is also important to further demonstrate the practical viability of metal removal through MFCs.

Continued improvements in drinking-water quality characterization and treatment/distribution infrastructure are required to address the expanding number of documented environmental contaminants. To better understand the variability in contaminant exposures from the drinking water resource (surface and groundwater), through the distribution process, to the point-of-use (tapwater), in 2019 a synoptic assessment of broad chemical exposures was conducted in system-specific source waters, finished drinking water and service-area tapwater from 10 drinking water treatment facilities in the greater Minneapolis/St. Paul area of Minnesota, United States. Source water, finished water (collected pre-distribution in the treatment facility), and tapwater samples were analyzed for 465 unique organic compounds, 34 inorganic constituents, and 3 field parameters as well as estrogen, androgen, and glucocorticoid bioactivities. Mixtures of organic and inorganic contaminants were prevalent in source water, finished water, and tapwater samples, indicating the continued need for broad assessments of mixed contaminant exposures to characterize potential drinking-water human health outcomes. Contaminant concentrations were similar among drinking water sources and no exceedances of Environmental Protection Agency maximum contaminant level(s) (MCL) were observed in any treated sample (finished water or tapwater) in this study. No treated sample contained estrogenic, androgenic, or glucocorticoid activity at concentrations that may cause adverse human health effects. However, there were multiple exceedances of non-enforceable MCL goal(s) (MCLG), and other health advisories combined with frequent exceedances of benchmark-based hazard indices in both finished water and tapwater samples. These results indicate that exposure to contaminant mixtures is a potential public health concern underscoring our continued efforts to assess contaminant mixture exposures at the drinking-water point of consumption using a broad analytical scope.

In December 2019, SARS-CoV-2, the virus that causes coronavirus disease 2019, was first reported and subsequently triggered a global pandemic. Wastewater monitoring, a strategy for quantifying viral gene concentrations from wastewater influents within a community, has served as an early warning and management tool for the spread of SARS-CoV-2 in a community. Ohio built a collaborative statewide wastewater monitoring network that is supported by eight labs (university, government, and commercial laboratories) with unique sample processing workflows. Consequently, we sought to characterize the variability in wastewater monitoring results for network labs. Across seven trials between October 2020 and November 2021, eight participating labs successfully quantified two SARS-CoV-2 RNA targets and human fecal indicator virus targets in wastewater sample aliquots with reproducible results, although recovery efficiencies of spiked surrogates ranged from 3 to 75%. When SARS-CoV-2 gene fragment concentrations were adjusted for recovery efficiency and flow, the proportion of variance between laboratories was minimized, serving as the best model to account for between-lab variance. Another adjustment factor (alone and in different combinations with the above factors) considered to account for sample and measurement variability includes fecal marker normalization. Genetic quantification variability can be attributed to many factors, including the methods, individual samples, and water quality parameters. In addition, statistically significant correlations were observed between SARS-CoV-2 RNA and COVID-19 case numbers, supporting the notion that wastewater surveillance continues to serve as an effective monitoring tool. This study serves as a real-time example of multi-laboratory collaboration for public health preparedness for infectious diseases.

Microplastics in the aquatic system are among the many inevitable consequences of plastic pollution, which has cascading environmental and public health impacts. Our study aimed at analyzing surface interactions and leachate production of six microplastics under ultraviolet (UV) irradiation. Leachate production was analyzed for the dissolved organic content (DOC), UV, and fluorescence through excitation emission (EEM) to determine the kinetics and mechanisms involved in the release of organic matter by UV irradiation. The results suggested there was a clear trend of organic matter being released from the surface of the six microplastics caused by UV irradiation based on DOC, UV absorbance, and EEM intensity increasing with time. Polystyrene had the greatest and fastest increase in DOC concentrations, followed by the resin coated polystyrene. Experiments conducted at different temperatures indicated the endothermic nature of these leaching mechanisms. The differences in leachate formation for different polymers were attributed to their chemical makeup and their potency to interact with UV. The aged microplastic samples were analyzed by Fourier-transform infrared spectroscopy (FT-IR), Raman, and X-ray photoelectron spectroscopy (XPS), to determine the surface changes with respect to leachate formation. Results indicated that all microplastics had increasing carbonyl indices when aged by UV with polystyrene being the greatest. These findings affirm that the leachate formation is an interfacial interaction and could be a significant source of organic compound influx to natural waters due to the extremely abundant occurrence of microplastics and their large surface areas.