UV light-based advanced oxidation processes have shownconsiderablepromise for mitigation of trace organic contaminants (TrOCs). Recentwork has garnered interest in ambient NO3– as a photooxidant within UV treatment processes. This work providesa systematic investigation on the efficacy of NO3– as a photooxidant for removal of aqueous 17β-estradiol (17β-E2)and its metabolites, estrone (E1) and estriol (E3). Results demonstratethat even low (1 mg L–1) concentrations of NO3– enhance degradation of 17β-E2 by>48% during medium-pressure UV (MP UV) treatment in comparisontocontrol conditions, and NO3– concentrations≥5 mg L–1 resulted in >90% removal of17β-E2at fluences ≥1000 mJ cm–2. Three photoproductsconsistent with known nitrogenous byproducts of 17β-E2 werealso observed throughout treatment and found to persist even underhigh (2000 mJ cm–2) fluence conditions. In a municipalwastewater matrix, estrogen removal was improved under high (25 mgL–1) NO3– conditionsas compared to ambient (∼3 mg L–1) levels.This work demonstrates the utility of NO3– as an in situ photooxidant for removal of TrOCssuch as steroid estrogens in real waters and provides an impact tostakeholders interested in leveraging these processes in complex matricessuch as municipal wastewater.

Removal of carcinogenicarsenic (As) from groundwateris essentialfor providing safe drinking water. Arsenate (As­(V)) is more effectivelyremoved in groundwater filters than arsenite (As­(III)), making theoxidation of As­(III) to As­(V) a key step in the treatment process.This study distinguishes between surface-catalytic and biologicalAs­(III) oxidation on natural manganese oxide (MnOx) coated filter sand, since it is unknown which pathway dominatesin filters. The MnOx coated sand was collectedfrom a full-scale groundwater filter and consisted of a mixture ofdifferent abiotically and biologically formed Mn oxides, such as Birnessiteand Todorokite. A lab-scale filter setup was operated with As­(III)-containingwater. Within 3 weeks, a shift from surface-catalytic to biologicalAs­(III) oxidation was observed. Initially, surface-catalytic As­(III)oxidation (kCHEM = 0.318 min–1) was coupled to Mn­(II) release at a ratio of 0.96, approximatingthe stoichiometric ratio of 1. This coupling disappeared over time,indicating the biological nature of the reaction, as confirmed bymicrobial inhibition. An increase in relative abundance of the knownAs-oxidizing families Comamonadaceae, with Polaromonas as the dominant genus, and Microscillaceae were found post experiments. Except for these changes, the microbialcommunity on the sand grains stayed relatively similar prior to andpost experiments. No significant changes in the physical-chemicalproperties of the MnOx coating were foundpost experiments. A first-order biological As­(III) oxidation rateconstant kBIO of 4.64 min–1 was found, yielding a half-life of 9 s. This represents a 14-foldacceleration compared with surface-catalytic oxidation, revealingthat kinetic limitations rather than surface passivation can be attributedto the loss of surface-catalytic oxidation. Our study demonstratesthat biological oxidation of As­(III) can outpace the acknowledgedoxidizing power of MnOx, offering a potentialnew pathway for the development of effective As removal systems.

Monitoring surface water temperature (SWT) in transitionalenvironmentsremains challenging due to the interplay of natural and anthropogenicprocesses, which introduce greater complexity than in open-ocean systems.This study evaluates four SWT products for their ability to capturetemperature dynamics in the Venice Lagoon, a well-monitored coastalsystem. The assessment included (1) output from the hydrodynamic modelSHYFEM (System of Hydrodynamic Finite Element Module), (2) a satellite-basedLevel 4 product from the European Space Agency Climate Change Initiative(ESA CCI), (3) the Landsat 8 Level 2 standard thermal product, and(4) Landsat 8 Level 1 data processed using the Thermal AtmosphericCorrection Tool (TACT). Validation against in situ observations indicatedthat SHYFEM and TACT showed lower bias (−0.48 °C and −0.30°C, respectively) and RMSE (∼1.2 °C) than the otherproducts. SHYFEM effectively reproduced intra-annual SWT trends withcomprehensive temporal coverage, while TACT captured fine-scale spatialfeatures, including thermal anomalies from industrial discharges.Building on this, an integrated product combining SHYFEM and TACTwas developed, providing a more accurate and coherent representationof spatiotemporal SWT dynamics. This transferable framework advancesunderstanding of thermal variability in transitional waters and haspotential to support ecosystem management and climate adaptation strategies.

Surface water-based utilities increasingly face challengesin drinkingwater production during prolonged droughts and heavy rainfall events.We assessed the impact of climate and hydrological variability ontrihalomethane (THM) levels in two drinking water treatment plantsin Barcelona: one river-based (Llobregat plant) and one reservoir-based(Ter plant). We examined data from 15 years (2010–2024) usinggeneralized additive models (GAMs) to evaluate the change (β)in chloroform, bromodichloromethane, dibromochloromethane, bromoform,and total THMs (THM4), by extreme (≤percentile 10, ≥percentile90) hydrometeorological predictors, including temperature, river flow,or reservoir level relative to normal conditions (P10–P90),and the Standardized Precipitation Evapotranspiration Index (SPEI1). In the Llobregat plant, THMs were unaffected under low river flowevents (≤P10), while THM4 decreased by −1.41 (confidenceinterval (CI) 95%: −2.77, −0.05) during high river flowevents (≥P90), mainly driven by bromoform (β: −2.64,CI 95%: −3.61, −1.67). In the Ter plant, THM4 increasedby 1.64 (CI 95%:0.09, 3.19) and 4.08 (CI 95%:0.83, 7.33), respectively,under high (≥P90) and low (≤P10) reservoir levels. Overall,moderate effects of extreme weather events on THM levels were observed,attributed to climate-resilient water management strategies. Furtherresearch is needed in other settings with diverse water sources andmanagement.

Despite advancesin the removal of pharmaceutical residues fromaqueous effluents, carbamazepine (CBZ) remains challenging due toits persistence. The low removal efficiency of conventional wastewatertreatments reinforces the need to develop innovative approaches, suchas hybrid systems. This study combined photo-Fenton reactions withthe enzyme laccase (Lac) to effectively remove CBZ from aqueous solutionsin batch and continuous-flow regimes. Lac was immobilized on functionalizedmagnetite nanoparticles (MNPs) to improve stability and operationalefficiency. Investigation of the effects of pH, temperature, UVC radiation,and H2O2 dose on Lac activity revealed promisingresults. Immobilized Lac retained 77.7% of its initial activity after60 min of UVC exposure. In contrast, the free enzyme lost its activitywithin 30 min of exposure. In batch mode, the Lac-MNPs/UVC/H2O2 system with 2,2’-azino-bis­(3-ethylbenzothiazoline-6-sulfonicacid) diammonium salt (ABTS) as the inducer degraded 91.9% of CBZin 15 min of reaction at neutral pH. For continuous operation mode,optimization based on a Central Composite Rotatable Design achieved91.1% CBZ removal at 10 min space-time, 20:1 H2O2:CBZ molar ratio, and 30 μmol L–1 ABTS. Thehigh removal efficiency in both batch and continuous modes indicatesthe potential application of the developed hybrid laccase-photo-Fentontreatment for effective CBZ degradation.

To advance a nitrogen circular economy, wastewater treatmentplants(WWTPs) must use technologies that recover waste nitrogen and transformit into valuable products. One emerging option is partition–release–recover(PRR) technology. It transforms waste nitrogen into cyanophycin-accumulatingorganism microbial protein (CAO MP), which can be used as a proteinsource in animal feed. In this study, we perform a life cycle assessmentand techno-economic analysis of a prospective WWTP configuration thatincorporates this technology and assess whether it merits furtherdevelopment. Conventional activated sludge and anaerobic/anoxic/oxicWWTP systems are comparator baseline systems. We compare CAO MP tofive different protein sources (soybean meal, alfalfa feed, fishmeal,cottonseed feed, and dried distiller grain solubles). The PRR approachhas a median GWP that is 1–32% lower than the comparator WWTPsystems. The median levelized cost of wastewater treatment using thePRR technology is 34–58% lower than the A2O configuration.Finally, CAO MP shows substantially lower global warming potentialand water consumption compared to traditional protein sources. Weconclude that the PRR pathway to transform waste nitrogen into CAOMP is a promising pathway toward more sustainable nitrogen recoverytechnology and protein production, warranting further research anddevelopment.

Freshwater salinization is a threat to biodiversity conservation. Winter road deicing salt use is a dominant driver of freshwater salinization in north temperate regions that experience winter temperatures below 0 °C. In Canada, the identification and management of areas vulnerable to road salt contamination is the least-complied-with tenet of the Canadian Code of Practice for the Environmental Management of Road Salts. To aid delineation of salt vulnerable areas, we developed and applied a framework for identifying dominant road salt loading source areas relative to aquatic species at risk critical habitat. We estimated per-event road salt loading at the subwatershed scale from roads and parking areas to determine contributions from different land-use classes and road types. We spatially focused on a watershed containing Redside Dace (Clinostomus elongatus), a fish species listed as federally and provincially endangered in Canada and Ontario, respectively. Applying uncertainty analysis, we found that cumulative road salt inputs on parking areas dominated total subwatershed-scale inputs. We recommend enhanced management of smaller-scale private road salt use, as the cumulative effect of smaller-scale salt use can be the largest source of watershed road salt loading. Furthermore, we emphasize the need to include critical habitat explicitly in salt vulnerable area delineations.

Persistent sanitation gaps in limited-resource ruralcommunitiesacross the United States continue to hinder progress toward nationalsustainable development goals. Addressing these communities’wastewater needs has led to a substantial rise in decentralized wastewatersystems (DWSs). However, the ongoing nationwide workforce crisis threatensthe effectiveness of these systems’ management, including operationand maintenance (O&M). Current literature narrowly frames workforcechallenges as labor shortages, overlooking critical and deeper systemicissues. Consequently, policy-informed environmental workforce strategiesremain a pressing national need. Here, we develop an integrated cross-pathwayapproach for achieving sustainable decentralized wastewater workforcedevelopment by investigating the root causes of both shortages andshortcomings that emerge across four interconnected career pathways:academic, regulatory, professional, and skilled trade. Through theoreticalthematic analysis of 30 semistructured interviews with stakeholdersacross rural Alabama’s Black Belt, we uncover how misalignedexpectations, disconnected responsibilities, and siloed institutionscollectively erode the capacity of the DWS workforce. Our findingshighlight targeted policy interventions, including state administrativecode reforms to promote performance-based regulation, mandate proactiveO&M, and strengthen state-led, community-driven engagement. Byexposing how fragmented career pathways undermine effective DWS governancein limited-resource rural communities, this work joins ongoing effortsto address complex environmental problems and advance sustainabledevelopment.

Growing concern over plastic pollution has intensifiedresearchon biodegradable alternatives, such as polyhydroxybutyrate (PHB),a biopolymer produced by cyanobacteria. Despite their sustainabilityadvantages, photoautotrophic PHB production remains limited, and cultivationstrategies need optimization. In this study, five cyanobacterial strainswere isolated from environmental microbiome cultures to evaluate theirPHB production potential. The goal was to identify the most productivestrains and optimal conditions for polymer synthesis. Cultures weregrown in modified BG11 media (without nitrogen, phosphorus, or inorganiccarbon) and in a secondary effluent from treated urban wastewater,both supplemented with acetate (0, 0.6, or 4 g/L) and incubated for7 days in darkness. The biomass remained stable in most strains butdeclined to 0.28 g/L in the secondary effluent, except for one Leptolyngbya sp. strain that increased the biomass withacetate. The highest PHB yield per acetate consumed was achieved by Synechocystis sp. from an agricultural pond, reaching 3.1%dry cell weight in modified BG11 with 0.6 g/L acetate. In the secondaryeffluent, the maximum PHB content reached 2.9% in another Leptolyngbya sp. strain with 4 g/L acetate. These findingshighlight strain-specific responses and the potential of wastewater-basedcultivation for sustainable bioplastic production.

Antimicrobial resistance (AMR) is a global health challenge,andmonitoring different demographic populations can improve our understandingof its spread and prevalence in urban settlements. This study appliesbuilding-level wastewater-based epidemiology (WBE) to analyze theresistome and mobilome of age-segregated populations from an elementaryschool (School), a university residence (UnivRes), and an elderlycare facility (ElderlyRes) all located in Girona (Catalonia, Spain).Metagenomic analyses were subsequently conducted to investigate differencesin bacterial communities, antibiotic resistance genes (ARGs), andmobile genetic elements (MGEs). The results revealed age-linked variationsin the relative abundance and diversity of ARGs. The wastewater collectedat the School exhibited the highest abundance of ARGs, while the ElderlyResshowed the highest diversity. Furthermore, sequences affiliated withbacterial pathogens were more prevalent in samples from both the Schooland the ElderlyRes, emphasizing potential public health implications.Among the 12 bacterial genera most strongly correlated with ARGs (Pearson R > 0.7), 11 were identified as members of the gut microbiota,underscoring their predominant role as reservoirs of resistance comparedto bacteria of environmental origin. By integrating localized wastewatersampling with metagenomics, our study uncovers demographic-specificresistome patterns, delivering actionable evidence to strengthen AMRsurveillance and intervention strategies in urban populations.