ACS ES&T water最新文献

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.

Cyanobacterial harmful algal blooms (CyanoHABs) pose global risks to public health, ecosystems, and economies. Despite advancements in satellite remote sensing, monitoring gaps persist, particularly in smaller, remote, and resource-limited regions, where CyanoHABs often remain undetected. Satellite-based methods, though effective for large-scale monitoring, suffer from a low spatial resolution, cloud cover, and reliance on in situ validation data. Traditional in situ monitoring equipment, including high-precision spectroradiometers, is costly and logistically challenging, further exacerbating global monitoring inequities. Cyanosense 2.0 (CS2.0) is a low-cost system for real-time in situ CyanoHAB detection and satellite validation designed to address these monitoring voids. CS2.0 integrates two hyperspectral Hamamatsu spectrometers and a microcontroller system, recording Remote Sensing Reflectance (R_rs) with high agreement to industry-grade instruments (R ² = 0.86, Normalized Root Mean Squared Error (NRMSE) = 9.82%), at a fraction of the cost (∼$1300). During field validation in multiple CyanoHAB-prone U.S. lakes, CS2.0 showed a strong performance when tested for widely used satellite-based CyanoHAB models and indices (R ² = 0.74-0.83; NRMSE = 13%-18%). The system's weatherproof design supports long-term autonomous deployments, making it functional in remote environments. As a scalable and accessible solution, CS2.0 holds the potential to democratize CyanoHAB monitoring and improve global water quality assessments, especially in under-represented regions.

Understanding the environmental impacts and economic costs of treatment technologies is essential for developing sustainable strategies for managing per- and polyfluoroalkyl substances (PFASs). This study focuses on the treatment of PFAS-contaminated landfill leachate using foam fractionation (FF) technology. A parametrized life cycle assessment and life cycle costing analysis were conducted to evaluate the performance of one-stage and three-stage FF systems. Full-scale operational data and EPA design models were used to assess environmental and economic impacts based on a functional unit of treating 1000 m³ of PFAS-contaminated landfill leachate. The global warming potential was estimated at 818 kg CO₂ eq for the one-stage system with 20% foam fraction, 357 kg CO₂ eq for the one-stage system with 1% foam fraction, and 402 kg CO₂ eq for the three-stage system with 1% foam fraction. Life cycle costs were estimated at $77.4 and $110.6 per functional unit for the one-stage and three-stage systems, respectively, using the net present value method. Sensitivity and scale-up analyses were also performed to evaluate the influence of operational parameters and system configurations on both environmental and economic outcomes.

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.