High-salinity mine water generated during membrane concentration of mine water contains structurally stable complex organic matter that resists removal and mineralization by conventional advanced oxidation processes, ultimately producing low-value by-product salts that hinder the resource utilization pathway. Leveraging the ultraviolet sensitivity of inherent chromophore groups and conjugated structures, this study developed an ultraviolet-activated assisted electrochemical process. By harnessing ultraviolet/oxidant synergies, this approach achieves ~89.9% total organic carbon removal, with minimal performance decay over 1000 hours. Combined with ultraviolet-visible spectroscopy, fluorescence excitation-emission-matrix spectroscopy, fourier transform ion cyclotron resonance mass spectrometer, and model contaminant experiments, this study elucidates an ultraviolet activation and radical attack synergistic mechanism driving organic mineralization. The direct integration of purified brine with bipolar membrane electrodialysis successfully produces acid, high-purity alkali (>99%), and reusable water, thereby closing the loop of impurities removal and resource recovery. This integrated system offers a strong strategy for high-value resource recovery and sustainable mine water management.

Abstract. The surface microlayer (SML), the uppermost ∼ 1 mm water layer at the air-water interface, plays a critical role in mediating Earth system processes, yet current knowledge of its composition and organic matter enrichment remains scattered across disciplines. Here, we present the first known meta-analysis of SML studies that quantitatively assesses the distributional characteristics of selected organic compounds, including organic carbon and nitrogen, amino acids, fatty acids, transparent exopolymer particles, carbohydrates, lipids and proteins, through probability density estimates, central tendency metrics and correlation analyses. Our results confirm a preferential enrichment of nitrogen-enriched, particulate organic matter in the SML, while also highlighting the significance of surfactant-specific factors that govern selective enrichment in the SML. We find that enrichment patterns can vary systematically with environmental and methodological conditions, underscoring the need to account for such influences when interpreting observations and developing SML-based models. We provide the full range of typical EF values for the studied compounds, offering a clear reference for assessing whether new measurements are typical or extreme. While delving into the ability of EFs to reflect organic matter partitioning in the SML, we also critically examine their limitations in capturing trophic variability and suggest that EF-based assessments be complemented with metrics that remove background variability from underlying water concentrations, enabling more accurate interpretations of true SML enrichment and informing future modelling efforts. Additionally, our meta-analysis demonstrates that logarithmic data transformations and robust central tendency estimates outperform traditional linear-scale approaches, providing more accurate and reliable SML enrichment estimates.

Polyamide 6,6 (PA66) is a key engineering polymer, whose unique mechanical properties arise from strong interchain hydrogen bonding. However, its hygroscopic nature makes it highly sensitive to water uptake, which markedly alters its thermomechanical behavior. Contrary to traditional experimental approaches, this study uses atomistic molecular dynamics (MD) simulations to investigate the role of water in modifying the glass transition temperature (Tg) and the viscoelastic response of amorphous PA66. Simulations capture a nonmonotonic dependence of Tg on water content. At low water concentrations, isolated water molecules bind to amide groups and restrict chain mobility, while beyond ∼2.5 wt %, water clustering disrupts the hydrogen-bond network and causes a pronounced Tg depression. Analysis of amide-group fluctuations reveals a master correlation between local segmental dynamics and bulk density, verifying the known temperature-humidity equivalence in terms of density variation. The computed Young's modulus exhibits systematic softening with increasing temperature and water content, consistent with experimental trends, albeit a more pronounced impact of water at low temperatures. Time-temperature superposition behavior is observed for both dry and hydrated systems. This work provides molecular-scale information on the hygromechanical coupling in PA66 and demonstrates the ability of MD simulations to predict water-induced transitions that govern the macroscopic behavior of polyamides.

Selenium is a critical trace element for equine health, involved in metabolic processes and antioxidant defense. However, imbalances in selenium intake can lead to health issues such as deficiency or toxicity. This article examines two different cases: five mares displaying reported clinical signs of interrupted ovarian activity, polyuria/polydipsia and weight loss, and a Quarter Horse stallion with reported neurological clinical signs. The mares were housed in the same stable and fed the same hay and pasture but received concentrates with varying selenium levels. Blood tests indicated elevated plasmatic selenium levels, suggesting selenium imbalances. Clinical signs were resolved by implementing an exclusion diet, and all mares resumed breeding within 3 months. In the second case, a 9-year-old Quarter Horse stallion presented with neurological clinical signs (tremors and shivering) and was referred for nutritional consultation. Plasma selenium levels confirmed selenium deficiency, as indicated by the referring clinician. The horse's diet was balanced and adjusted as required, and an initial supplement of selenium and vitamin E was added. After 28 days, with follow-up evaluations, the horse's selenium status improved, and the supplement was reduced. This underscores the importance of managing selenium intake carefully, considering environmental factors, the form of selenium supplementation and long-term health to ensure optimal health in horses. Selenium content in concentrates, forages and water should be carefully considered in all cases of suspected selenium imbalances, ensuring optimal selenium inclusion levels that do not exceed the established limits.

Positive vegetation response to nitrogen enrichment offsets salt marsh cover decline without altering dissolved carbon concentration in sediment pore water.

Fluorescence sensing mechanism of contaminant Cu2+ in water by up-converting nanoparticles.

Dietary metal(loid)s exposure and their health risks to patients with gastric precancerous lesions and gastric cancer in Anhui Province, Eastern China.

New concept of spectroscopic detection of the cationic porphyrin via its spontaneous aggregation at Au@thermoresponsive polymer core@shell nanocomposites.

Implementation of an easy and cost-effective method for POCIS in situ calibration using o-DGT for pharmaceutical compounds.

Effects of carbamazepine on visual function in early life stage fish.

The distribution of the 129I radioisotope concentration in surface waters across Romania

Multi-step forecasting of chlorophyll-a concentration in coastal waters through Wavelet Dense Attention Transformer model.

A stratified multimedia model for neonicotinoid fate analysis: Application to imidacloprid in the Yangtze River Basin.

Relationship between microplastics and heavy metals in Tam Giang-Cau Hai lagoon sediments.

Limited bioconcentration of water-associated pharmaceutical active compounds through short-term exposure in signal crayfish (Pacifastacus leniusculus).

Water is a basic need of living things that is very important to maintain its quality so that it does not cause problems. The method that can be used to improve water quality is to carry out the coagulation method using moringa seed coagulant (moringa oleifera) and alum which has been proven to be able to improve the quality of water. Both coagulants can reduce the following parameters, turbidity by reducing TSD, neutralizing pH, reducing dissolved metal levels, color, and reducing microorganisms contained in it such as E-coli bacteria and total coliform. The results of this study indicate that the two coagulants can reduce the parameter values of TDS, turbidity, iron content, E-coli, color, and pH in the sample water to be below the maximum limit or in accordance with drinking water quality standards, but the nitrate parameter is not yet below the maximum level. The optimum concentration to improve the quality of well water into drinking water is 2.5 ppm with an optimum residence time of 4 weeks.

Urban rivers often contain a complex mixture of contaminants including per- and polyfluoroalkyl substances (PFAS), metals, and various salts. This study aimed to investigate the sediment–water partitioning characteristics of PFAS in urban rivers and analyze the hydrochemical causes of this specific feature. We sampled paired water and sediment samples from urban rivers in a reclaimed water irrigation area in Beijing City. The average total PFAS concentrations in the river water and sediment were 28.44 ± 16.37 ng/L and 6.41 ± 4.20 ng/g dw, respectively. Short-chain PFAS from C4 to C6 and PFCA congeners dominated in the water, while long-chain PFAS above C8 and PFSA congeners dominated in the sediment. The average sediment–water ratio (Log Kd) of PFAS at each site showed an increasing trend with chain length, and was generally higher than that observed in seawater, natural rivers, and lakes, indicating a specific sediment–water partitioning behavior of PFAS in urban rivers. This difference is likely due to the distinct hydrochemical characteristics of the urban rivers, where elevated TDS, the presence of surfactants, and the coexistence of multiple heavy metal ions collectively promote PFAS adsorption onto suspended particulate matter and enhance their accumulation in sediments through sedimentation.

Background: As climate change, industrial activities and urbanization alter water sources, ongoing mineral analysis becomes vital for sustainable water management and regulatory compliance. This study was done to apply the technique of atomic absorption spectroscopy in determining mineral content in water from different sources. It emphasized how natural and anthropogenic factors influence water quality, impacting both ecosystem and human safety. Methods: The study was done to measure mineral content of water from different sources with the help of flame atomic absorption spectroscopy (AAS). We took water samples from urban tap- water, local well-water and a spring-water. With the help of AAS calcium, magnesium, iron, sodium, potassium and zinc levels were measures in water samples. In order to verify the reliability of the method, the reference sample was determined. The accuracy of the calibration curve was evaluated by an independent calibration verification. Results: Magnesium and calcium were found predominantly in spring water, while zinc and iron were absent, which suggested that mineral profile of natural groundwater is influenced by geological and environmental conditions specific to location. The presence of zinc and iron in tap and well water is attributed to the plumbing materials or environmental factors influencing water supplies. Conclusions: Understanding mineral dynamics in water helps to protect public health and preserve environmental integrity in a rapidly changing world. This work shows that AAS technique is highly sensitive, specific and affordable method for detecting trace and toxic elements, which implements AAS as indispensable tool in modern laboratories and research centres.

Lake Tana, Ethiopia's largest natural lake and the headwater of the Blue Nile, provides critical ecosystem services and socio-economic benefits. However, rapid agricultural expansion in the Lake Tana sub-basin has led to increased pesticide use, which raises serious environmental concerns. This systematic review synthesi zes information on agricultural pesticide use, their residues in fish, water, and sediments, and the associated ecological and human health risks. A total of 66 active ingredients were identified across 13 districts, with the highest pesticide use reported in Libokemkem, Fogera, and Gondar Zuria. Pesticide use was dominated by insecticides, including several WHO-classified hazardous compounds. Risk Quotients derived from fish body residues identified imidacloprid, oxamyl, and flazasulfuron as priority pesticides posing high to very high risks to Labeobarbus spp. In Lake Tana, legacy organochlorine pesticides (endosulfan, lindane, endrin, DDT, and dieldrin) posed high to very high risks to Oreochromis niloticus. Human health risk assessment based on fish consumption indicated negligible non-carcinogenic risks from both current-use and legacy pesticides. Potentially Affected Fraction (PAF) and multi-substance Potentially Affected Fraction (msPAF) analyses indicated severe ecological risks posed by the measured water concentrations across the Lake Tana sub-basin. Sediment-bound pesticides also posed consistently high ecological risks, particularly for persistent organochlorines (lindane, endrin, and dieldrin). Overall, these findings advocate the urgent need for improved pesticide regulation, better management of legacy contaminants, and the promotion of sustainable agricultural practices to protect the Lake Tana sub-basin and its vital ecosystem services.

Herbicides such as glyphosate have been widely used in agriculture for several decades, and their occurrence in surface waters has been documented worldwide. However, information on the seasonal variability and occurrence of glyphosate in tropical coastal river systems remains limited, particularly in regions of the Gulf of Mexico. The present study aimed to quantify glyphosate concentrations in surface water from the Jamapa river (Veracruz, Mexico) during dry and rainy seasons and to evaluate their temporal variability and regulatory relevance. Three sampling campaigns were conducted in 2022 (May, June, and July), and glyphosate was analyzed using a competitive enzyme-linked immunosorbent assay (ELISA). Glyphosate was detected in all samples, with mean concentrations of 1.32µg L⁻1 in May (dry season), 0.15µg L⁻1 in June, and 3.7µg L⁻1 in July (rainy season), showing statistically significant seasonal differences (p < 0.05). Concentrations exceeded the European drinking water guideline (0.1µg L⁻1) but remained below Mexican and other international regulatory limits. These results provide baseline information on the occurrence and seasonal behavior of glyphosate in the Jamapa River and highlight the importance of continued monitoring of emerging contaminants in tropical river basins influenced by agricultural activities.