ACS ES&T water最新文献

Effect-based methods (EBMs) are bioanalytical tools detecting bioactivity of chemical mixtures on different toxicological end points. EBMs have become increasingly important for water quality assessment and monitoring, particularly in Europe and Australia. To date, their application has not been reported for the assessment of water in Mexico, where tap water is often not consumed as drinking water due to perceived concerns of pollution from the distribution system. In this study, a battery of EBMs was applied to assess the quality of drinking and potable water from Mexico City and surrounding states. The results were compared with international reports and proposed effect-based trigger (EBTs) values. Aryl hydrocarbon receptor bioactivity and androgen receptor (AR) inhibition were detected in tap water and household-filtered water. Estrogen receptor activity was observed in most of the samples, with the highest levels detected in water from the jug container. No bioactivities were detected for AR activity, genotoxicity, or oxidative stress. Although some of the samples were bioactive, the calculated bioanalytical equivalent concentrations (BEQs) were generally below the reported BEQs from other countries and below the proposed EBTs for drinking water. These findings indicate that the tested drinking and potable water sources in the surrounding states of Mexico City are of good quality.

Per- and polyfluoroalkyl substances (PFAS) are pervasive pollutants at historically contaminated sites throughout the United States and beyond. Two such sites in Rhode Island, USA, are textile-mill-associated waste retention ponds known to introduce PFAS contamination to the adjacent river, estuary, and eventually the Atlantic Ocean. Here, we thoroughly investigated the retention ponds as a long-term source of PFAS via water passive sampling, sediment coring, and laboratory-derived partitioning coefficients, K _d, with field sediment and water. Additional studies were performed to assess the mobility and estimate the mass fluxes of PFAS from sediment to water. Retention pond 1 was more contaminated (up to 26 ng/L PFOA in water and 74 ng/g PFTrDA in sediment). Derived log K _d values ranged from 1 to 5 for most PFAS, indicating a shift from relative mobility to high storage potential in sediment. Estimated loss fluxes from the sediment varied between 5 and 228 μg m^-2 year^-1, resulting in desorption times from 3 years for FPeSA to >100 years for FOSA. The combined evidence suggests that this textile mill retention pond, if left untreated, constitutes a source of long-term contamination to the river.

There is a pressing need to understand the pathways of textile fibers as anthropogenic pollutants in the environment. Current efforts to understand textile fiber pollution in waterways have relied on surface-sampling methodologies without consideration for environmental heterogeneity. Moreover, how nonplastic textile fibers behave in the environment is not known. Here, for the first time, we experimentally quantify the role that fiber type (cotton, wool, polyester, and acrylic) and riverbed roughness (flat, fine gravel, and coarse gravel) have on the vertical distribution of transported fibers using an experimental, recirculating flume. Analysis of the vertical profile distributions of 18,793 cotton, wool, polyester, and acrylic fibers indicated that bed substrate significantly altered fiber transport pathways, which was consistent across all tested fiber types. Our findings indicate that surface-only sampling will substantially under-record fiber fluxes, but such biases did not differ between any tested fiber types. Our findings provide key insights into fiber/bed interactions and transport pathways and imply that current monitoring methodologies significantly underestimate lotic (and potentially lentic) populations of fibers. We argue that it is crucial to sample for all fiber types, throughout the water column in all riverbed types, to understand fully the scale of riverine textile fiber pollution.

Selenium (Se) is an essential micronutrient but toxic at high concentrations, posing challenges for water treatment. This study investigated the removal of selenate (SeO₄ ^2-) and selenite (SeO₃ ^2-) using the strong-base anion-exchange resin IRA-900, particularly in the presence of competing sulfate (SO₄ ^2-). The performance of the commercially available resin IRA-900 was systematically investigated. The batch equilibrium behavior was studied in both single- and binary-component systems, and the kinetic behavior was investigated in single-component systems. Results confirmed a selectivity order of SeO₄ ^2- > SO₄ ^2- > SeO₃ ^2-, indicating preferential SeO₄ ^2- removal over competing SO₄ ^2- but lower affinity for SeO₃ ^2-. The maximum total exchange capacity was determined to be 2.04 mequiv/g. Furthermore, SeO₃ ^2- uptake was found to be pH-dependent, whereas SeO₄ ^2- uptake remained stable across a broad pH range. From a modeling perspective, the Law of Mass Action model effectively described equilibrium data, and a transport-reaction modeling framework captured removal kinetics of oxyanions including film and intraparticle diffusion. Finally, X-ray photoelectron spectroscopy confirmed ion exchange between chloride and Se oxyanions as the primary removal mechanism. These findings provide fundamental insights into the removal of Se oxyanions from aqueous solutions by ion exchange.

Sequencing batch reactors (SBRs) performing partial nitritation (PN) for treating high-strength ammonium wastewater are known to exhibit elevated levels of nitrous oxide (N₂O) emissions. This study investigated N₂O production and hydroxylamine accumulation in a PN-SBR operated using three distinct strategies. The N₂O emission factor (EF) and net production rate (N2OR) were determined under stable conditions for (i) single feeding with continuous aeration and one microaerobic stage before settling (strategy I), yielding EF = 4.4% and N2OR = 14 mg N g^-1 VSS d^-1; (ii) single feeding with multiple microaerobic stages distributed throughout the cycle (strategy II), yielding EF = 13.5% and N2OR = 85 mg N g^-1 VSS d^-1; and (iii) step feeding with one single microaerobic stage before settling (strategy III), yielding EF = 10% and N2OR = 45 mg N g^-1 VSS d^-1. The distribution of microaerobic stages throughout the cycle (strategy II) promoted the highest hydroxylamine accumulation (0.18 mg N L^-1) during the aerated stage, whereas strategy I showed the lowest accumulation (0.01 mg N L^-1). A strong positive correlation (R ² ≥ 0.9) was observed among the specific ammonium oxidation rate (AOR), specific N2OR, and bulk liquid hydroxylamine concentration during the aerated stages.

Climate change-related increases in organic carbon in surface waters may present challenges in meeting regulatory requirements with regard to drinking water quality. Treatment adaptation that alters natural organic matter (NOM), metal oxides, and water chemistry can have a downstream influence on lead release. We compared the effect of the coagulant and filter type on water quality and lead release in a galvanic lead solder-copper system. Aluminum sulfate (alum), polyaluminum chloride (PACl), anthracite/sand, and granular activated carbon (GAC) were tested in a pilot-scale system. Lead release was evaluated in a bench-scale dump and fill experiment with treated water dosed with 0-2 ppm zinc-orthophosphate. GAC contactors reduced organic carbon in both systems and had a strong protective effect on lead release, likely due to less NOM complexation and improved orthophosphate performance. At equivalent Al doses, organic carbon removal was comparable between PACl and alum, but PACl showed slower GAC exhaustion rates, improving the removal efficiency. PACl was linked with increased galvanic corrosion due to higher CSMR. Zinc-orthophosphate mitigated galvanic corrosion of lead solder. Treatment facilities can decrease lead release by removing NOM, but alternative coagulants that may be considered for enhanced NOM removal can increase the chloride concentration and have detrimental effects as well.

Properly operated and maintained drinking water distribution system (DWDS) storage tanks are crucial for allocating safe drinking water, but varying operational processes and infrequent maintenance can result in water quality degradation, including disinfectant residual loss, sediment accumulation, bacterial growth, and potential contamination. This study assessed how the physical, chemical, and hydraulic characteristics of representative chlorinated DWDS tanks relate to bacterial communities in water and sediment; investigated water quality variation by depth within tanks; and explored the infrastructure and management characteristics influencing bacterial community composition in tanks. Bulk water and sediment samples were collected from seven tanks in a chlorinated DWDS system, and 16S rRNA gene amplicon sequencing was used to characterize the bacterial community. Bulk water and sediment communities were distinct, dominated by Alphaproteobacteria and Gammaproteobacteria, respectively. Spatial variations as a function of distance from the treatment plant, tank-specific characteristics, and sediment accumulation were found to shape bacterial communities within tanks. Total coliforms and Escherichia coli were undetectable in all water samples, but genetic signatures indicated the presence of multiple genera associated with opportunistic pathogens (OPs). This study aims to establish a deeper understanding of the bacterial community within DWDS tanks and the impact that tank conditions and characteristics have on DWDS water quality.

UV light-based advanced oxidation processes have shown considerable promise for mitigation of trace organic contaminants (TrOCs). Recent work has garnered interest in ambient NO₃ ^- as a photooxidant within UV treatment processes. This work provides a 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 demonstrate that even low (1 mg L^-1) concentrations of NO₃ ^- enhance degradation of 17β-E2 by >48% during medium-pressure UV (MP UV) treatment in comparison to control conditions, and NO₃ ^- concentrations ≥5 mg L^-1 resulted in >90% removal of 17β-E2 at fluences ≥1000 mJ cm^-2. Three photoproducts consistent with known nitrogenous byproducts of 17β-E2 were also observed throughout treatment and found to persist even under high (2000 mJ cm^-2) fluence conditions. In a municipal wastewater matrix, estrogen removal was improved under high (25 mg L^-1) NO₃ ^- conditions as compared to ambient (∼3 mg L^-1) levels. This work demonstrates the utility of NO₃ ^- as an in situ photooxidant for removal of TrOCs such as steroid estrogens in real waters and provides an impact to stakeholders interested in leveraging these processes in complex matrices such as municipal wastewater.

Removal of carcinogenic arsenic (As) from groundwater is essential for providing safe drinking water. Arsenate (As-(V)) is more effectively removed in groundwater filters than arsenite (As-(III)), making the oxidation of As-(III) to As-(V) a key step in the treatment process. This study distinguishes between surface-catalytic and biological As-(III) oxidation on natural manganese oxide (MnO _x ) coated filter sand, since it is unknown which pathway dominates in filters. The MnO _x coated sand was collected from a full-scale groundwater filter and consisted of a mixture of different abiotically and biologically formed Mn oxides, such as Birnessite and Todorokite. A lab-scale filter setup was operated with As-(III)-containing water. Within 3 weeks, a shift from surface-catalytic to biological As-(III) oxidation was observed. Initially, surface-catalytic As-(III) oxidation (k _CHEM = 0.318 min^-1) was coupled to Mn-(II) release at a ratio of 0.96, approximating the stoichiometric ratio of 1. This coupling disappeared over time, indicating the biological nature of the reaction, as confirmed by microbial inhibition. An increase in relative abundance of the known As-oxidizing families Comamonadaceae, with Polaromonas as the dominant genus, and Microscillaceae were found post experiments. Except for these changes, the microbial community on the sand grains stayed relatively similar prior to and post experiments. No significant changes in the physical-chemical properties of the MnO _x coating were found post experiments. A first-order biological As-(III) oxidation rate constant k _BIO of 4.64 min^-1 was found, yielding a half-life of 9 s. This represents a 14-fold acceleration compared with surface-catalytic oxidation, revealing that kinetic limitations rather than surface passivation can be attributed to the loss of surface-catalytic oxidation. Our study demonstrates that biological oxidation of As-(III) can outpace the acknowledged oxidizing power of MnO _x , offering a potential new pathway for the development of effective As removal systems.

Monitoring surface water temperature (SWT) in transitional environments remains challenging due to the interplay of natural and anthropogenic processes, which introduce greater complexity than in open-ocean systems. This study evaluates four SWT products for their ability to capture temperature dynamics in the Venice Lagoon, a well-monitored coastal system. The assessment included (1) output from the hydrodynamic model SHYFEM (System of Hydrodynamic Finite Element Module), (2) a satellite-based Level 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 Atmospheric Correction Tool (TACT). Validation against in situ observations indicated that SHYFEM and TACT showed lower bias (-0.48 °C and -0.30 °C, respectively) and RMSE (∼1.2 °C) than the other products. SHYFEM effectively reproduced intra-annual SWT trends with comprehensive temporal coverage, while TACT captured fine-scale spatial features, including thermal anomalies from industrial discharges. Building on this, an integrated product combining SHYFEM and TACT was developed, providing a more accurate and coherent representation of spatiotemporal SWT dynamics. This transferable framework advances understanding of thermal variability in transitional waters and has potential to support ecosystem management and climate adaptation strategies.