ACS ES&T water最新文献

Surface water-based utilities increasingly face challenges in drinking water production during prolonged droughts and heavy rainfall events. We assessed the impact of climate and hydrological variability on trihalomethane (THM) levels in two drinking water treatment plants in Barcelona: one river-based (Llobregat plant) and one reservoir-based (Ter plant). We examined data from 15 years (2010-2024) using generalized additive models (GAMs) to evaluate the change (β) in chloroform, bromodichloromethane, dibromochloromethane, bromoform, and total THMs (THM4), by extreme (≤percentile 10, ≥percentile 90) hydrometeorological predictors, including temperature, river flow, or reservoir level relative to normal conditions (P10-P90), and the Standardized Precipitation Evapotranspiration Index (SPEI 1). In the Llobregat plant, THMs were unaffected under low river flow events (≤P10), while THM4 decreased by -1.41 (confidence interval (CI) 95%: -2.77, -0.05) during high river flow events (≥P90), mainly driven by bromoform (β: -2.64, CI 95%: -3.61, -1.67). In the Ter plant, THM4 increased by 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. Further research is needed in other settings with diverse water sources and management.

Despite advances in the removal of pharmaceutical residues from aqueous effluents, carbamazepine (CBZ) remains challenging due to its persistence. The low removal efficiency of conventional wastewater treatments reinforces the need to develop innovative approaches, such as hybrid systems. This study combined photo-Fenton reactions with the enzyme laccase (Lac) to effectively remove CBZ from aqueous solutions in batch and continuous-flow regimes. Lac was immobilized on functionalized magnetite nanoparticles (MNPs) to improve stability and operational efficiency. Investigation of the effects of pH, temperature, UVC radiation, and H₂O₂ dose on Lac activity revealed promising results. Immobilized Lac retained 77.7% of its initial activity after 60 min of UVC exposure. In contrast, the free enzyme lost its activity within 30 min of exposure. In batch mode, the Lac-MNPs/UVC/H₂O₂ system with 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) as the inducer degraded 91.9% of CBZ in 15 min of reaction at neutral pH. For continuous operation mode, optimization based on a Central Composite Rotatable Design achieved 91.1% CBZ removal at 10 min space-time, 20:1 H₂O₂:CBZ molar ratio, and 30 μmol L^-1 ABTS. The high removal efficiency in both batch and continuous modes indicates the potential application of the developed hybrid laccase-photo-Fenton treatment for effective CBZ degradation.

To advance a nitrogen circular economy, wastewater treatment plants (WWTPs) must use technologies that recover waste nitrogen and transform it into valuable products. One emerging option is partition-release-recover (PRR) technology. It transforms waste nitrogen into cyanophycin-accumulating organism microbial protein (CAO MP), which can be used as a protein source in animal feed. In this study, we perform a life cycle assessment and techno-economic analysis of a prospective WWTP configuration that incorporates this technology and assess whether it merits further development. Conventional activated sludge and anaerobic/anoxic/oxic WWTP systems are comparator baseline systems. We compare CAO MP to five different protein sources (soybean meal, alfalfa feed, fishmeal, cottonseed feed, and dried distiller grain solubles). The PRR approach has a median GWP that is 1-32% lower than the comparator WWTP systems. The median levelized cost of wastewater treatment using the PRR technology is 34-58% lower than the A²O configuration. Finally, CAO MP shows substantially lower global warming potential and water consumption compared to traditional protein sources. We conclude that the PRR pathway to transform waste nitrogen into CAO MP is a promising pathway toward more sustainable nitrogen recovery technology and protein production, warranting further research and development.

Persistent sanitation gaps in limited-resource rural communities across the United States continue to hinder progress toward national sustainable development goals. Addressing these communities' wastewater needs has led to a substantial rise in decentralized wastewater systems (DWSs). However, the ongoing nationwide workforce crisis threatens the effectiveness of these systems' management, including operation and maintenance (O&M). Current literature narrowly frames workforce challenges as labor shortages, overlooking critical and deeper systemic issues. Consequently, policy-informed environmental workforce strategies remain a pressing national need. Here, we develop an integrated cross-pathway approach for achieving sustainable decentralized wastewater workforce development by investigating the root causes of both shortages and shortcomings that emerge across four interconnected career pathways: academic, regulatory, professional, and skilled trade. Through theoretical thematic analysis of 30 semistructured interviews with stakeholders across rural Alabama's Black Belt, we uncover how misaligned expectations, disconnected responsibilities, and siloed institutions collectively erode the capacity of the DWS workforce. Our findings highlight targeted policy interventions, including state administrative code reforms to promote performance-based regulation, mandate proactive O&M, and strengthen state-led, community-driven engagement. By exposing how fragmented career pathways undermine effective DWS governance in limited-resource rural communities, this work joins ongoing efforts to address complex environmental problems and advance sustainable development.

The release of anabaenopeptins (APs) into source freshwater from cyanobacteria harmful algal blooms (cHABs) has raised concerns due to their reported abundance and inhibitory activity toward carboxypeptidases (CP). This study aimed to determine if chlorination, a widely used drinking water treatment, of AP-A, AP-B, and AP-679 inactivates their ability to inhibit carboxypeptidases A (CPA) and B (CPB). Each chlorinate treated AP's degradation by-products (DBPs) were analyzed via high-resolution mass spectrometry (HRMS) to track structural changes. This analysis suggested that site-specific chlorination begins with tyrosine residues. The resulting DBPs for each AP were then tested with standard enzyme assays to observe inhibitory changes to CPA and CPB. It was observed that AP-B DBPs retained potent inhibition of CPB. The lack of chlorine efficacy in inactivating AP-B is attributed to the ureido group arginine being unaffected by chlorination. As cHABs continue to pose global risks to drinking water supplies, further research is needed on AP inactivation, AP removal by drinking water treatment processes, and the impact of CP inhibition on human health.

Antimicrobial resistance (AMR) is a global health challenge, and monitoring different demographic populations can improve our understanding of its spread and prevalence in urban settlements. This study applies building-level wastewater-based epidemiology (WBE) to analyze the resistome and mobilome of age-segregated populations from an elementary school (School), a university residence (UnivRes), and an elderly care facility (ElderlyRes) all located in Girona (Catalonia, Spain). Metagenomic analyses were subsequently conducted to investigate differences in bacterial communities, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs). The results revealed age-linked variations in the relative abundance and diversity of ARGs. The wastewater collected at the School exhibited the highest abundance of ARGs, while the ElderlyRes showed the highest diversity. Furthermore, sequences affiliated with bacterial pathogens were more prevalent in samples from both the School and 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 compared to bacteria of environmental origin. By integrating localized wastewater sampling with metagenomics, our study uncovers demographic-specific resistome patterns, delivering actionable evidence to strengthen AMR surveillance and intervention strategies in urban populations.

Growing concern over plastic pollution has intensified research on biodegradable alternatives, such as polyhydroxybutyrate (PHB), a biopolymer produced by cyanobacteria. Despite their sustainability advantages, photoautotrophic PHB production remains limited, and cultivation strategies need optimization. In this study, five cyanobacterial strains were isolated from environmental microbiome cultures to evaluate their PHB production potential. The goal was to identify the most productive strains and optimal conditions for polymer synthesis. Cultures were grown in modified BG11 media (without nitrogen, phosphorus, or inorganic carbon) and in a secondary effluent from treated urban wastewater, both supplemented with acetate (0, 0.6, or 4 g/L) and incubated for 7 days in darkness. The biomass remained stable in most strains but declined to 0.28 g/L in the secondary effluent, except for one Leptolyngbya sp. strain that increased the biomass with acetate. 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 secondary effluent, the maximum PHB content reached 2.9% in another Leptolyngbya sp. strain with 4 g/L acetate. These findings highlight strain-specific responses and the potential of wastewater-based cultivation for sustainable bioplastic production.

Ultraviolet C light-emitting diodes (UV C LEDs) have demonstrated effectiveness in disinfection applications and proven suitability at scale for disinfection of municipal wastewater and drinking water. Technological advances in materials design and electrical efficiency have made high-intensity light delivery by UV C LEDs a reality and now poise these traditionally disinfection systems to serve a dual purpose for targeted remediation of trace organic contaminants (TrOCs). This work investigated the effectiveness of UV C light emission tailoring on the photodegradation dynamics of select TrOCs. Degradation kinetics and quantum yields of target compounds under 275 nm irradiation were governed by molar absorbance and chemical structure, and kinetics followed estrone (E1) > tryptophan > caffeine ≈ pCBA > urea. Secondary experiments compared the efficacy of a 275 nm UV LED and a medium-pressure mercury vapor (MP UV) system for photodegradation of two steroid estrogens, E1 and 17β-estradiol (17β-E2). Use of the 275 nm UV LED system substantially reduced fluence requirements and, in the case of 17β-E2, energy requirements, to achieve 90% degradation of the target compounds. Liquid chromatography-tandem mass spectrometry analysis of an E1 photodegradation product showed that the UV C LED system was more effective in eliminating both E1 and its associated photoproduct as compared to the MP UV system. This work demonstrates the effective use of UV LEDs for tailored photolysis of TrOCs and provides evidence for their use potential in applications outside of water disinfection.

Per-and polyfluoroalkyl substances (PFAS) present significant challenges for remediation due to their persistence in nature. Activated carbon is a widely used adsorbent for removing PFAS. In this study, three forms of activated carbon, granular activated carbon (GAC), powdered activated carbon (PAC), and ball-milled colloidal activated carbon (CAC_BM), are compared for their effectiveness in removing short and long-chain PFAS. Physical modification through ball-milling process enhanced the adsorptive properties of activated carbon, resulting in smaller particle size (d ₅₀ = 0.318 μm), increased surface area (968.59 m² g^-1), and improved suspension stability compared to conventional GAC and PAC. Kinetic experiments showed that CAC_BM demonstrated superior removal efficiencies of long-chain PFAS (up to 89% for perfluorooctanesulfonic acid (PFOS) and 73% for perfluorooctanoic acid (PFOA)), and moderate removal of short-chain PFAS (55% for perfluorobutanesulfonic acid (PFBS) and 30% for perfluorobutanoic acid (PFBA)). The pseudo-first-order model adequately described adsorption trends; however, the pseudo-second-order model provided a better fit, with intraparticle diffusion identified as the rate-limiting step. Isotherm studies indicated that PFAS adsorption aligned well with the Freundlich model. Competitive adsorption experiments revealed a hierarchical pattern. Overall, the study demonstrates CAC_BM as a promising adsorbent for remediation of PFAS-contaminated water systems.

Microplastic pollution has been found to negatively impact water quality and ecosystem health in numerous riverine environments at different spatial and temporal scales. However, many of the underlying principles controlling microplastic transport and retention mechanisms are still poorly understood. Here, we study the deposition behavior of nylon fibers and fragments (small and large) in flow-controlled stream flume experiments with gravel or mixed sediment. We use a stochastic modeling approach and Latin hypercube sampling to optimize the parameters describing microplastic deposition and resuspension and relate deposition rates to settling rates calculated using Stoke's law. Our experiments show that lower streamflow velocity leads to faster microplastic deposition, an effect that is shape-dependent and more pronounced for fibers. In experiments with similar flow velocity, large fragments were more quickly deposited in flumes containing gravel compared to mixed sediment. Stoke's settling rates and model-based deposition rates can differ by several orders of magnitude, especially for fibers. For our flume experiments, these differences are attributed to transitional and turbulent flow near the streambed. Results emphasize that microplastic net deposition and near-bed transport cannot be well described by Stoke's law. Results will further our understanding of microplastic fate and transport in riverine environments.