Search Results (1,814)

Drinking water treatment plants produce large quantities of Water Treatment Sludge (WTS), which negatively impacts the environment due to improper disposal. In this study, the mechanical performance of a hot-mix asphalt (HMA) containing WTS (referred to as HMA WTS) was evaluated and compared with a control mixture (HMA C), with a primary focus on its potential application in pavements constructed in warm-climate regions. In this way, the implementation of sustainable practices in road construction is promoted. The WTS was physicochemical characterized. Subsequently, the WTS was calcined at 200, 300, 500, and 800 °C to transform it into ash for use as filler (F). A calcination temperature of 500 °C was selected as optimal, based on the evaluation of the physical properties of mastic samples prepared with asphalt cement (AC) and calcined WTS. F/AC ratios of 0.11, 0.25, 0.43, and 0.67 were used, corresponding to filler contents between 0.5% and 2% in the HMA. Based on the stiffness and workability of the asphalt mastic, an F/AC ratio of 0.25 was selected, representing 1.0% filler in the HMA. Two mix designs (HMA C and HMA WTS) were developed according to the Marshall methodology to determine the Optimum Asphalt Content (OAC). Mechanical performance and durability tests were conducted to evaluate the behavior of the asphalt mixtures. The results indicate that WTS increased mastic stiffness, enhancing the mechanical performance of the HMA (greater resistance under monotonic loading and improved rutting and fatigue resistance) while reducing OAC, thus representing a promising alternative for its management and final disposal and contributes to sustainability in pavement engineering. However, durability-related properties (resistance to moisture damage, raveling, and abrasion) decreased due to the reduction in OAC. Full article

Mining can significantly affect the spatial distribution and temporal evolution of groundwater chemistry. From July to August 2024, the research team collected 26 surface water and groundwater samples in the Shengli Coal Mine area of the Mongolian Plateau, conducting comprehensive hydrogeochemical analyses on surface water flowing through the mining area, groundwater within the mining area, seepage water, and groundwater outside the mining area. The results indicate that groundwater in this region is notably affected by human activities such as mining operations. Specifically, in surface water flowing through the mining area, concentrations of total dissolved solids (TDS), sulfates, nitrates, and nickel showed significant increases. Compared to groundwater systems in other areas of the Mongolian Plateau, nickel levels in the mining area’s groundwater were significantly higher, while nitrate levels exhibited the opposite trend. A significant positive correlation was observed between metal element concentrations in surface water and groundwater. The study found that abnormal distributions of heavy metals such as beryllium (Be), thallium (Tl), and tin (Sn) may originate from point-source pollution caused by mining activities. Furthermore, concentrations of manganese (Mn), arsenic (As), and antimony (Sb) in the groundwater of this area exceeded relevant regulatory limits, with arsenic being particularly prominent. The levels of arsenic in both surface water and groundwater may pose carcinogenic risks to human health. This study shows that nearly half of the sampled water bodies in the area require purification treatment to meet drinking water standards, highlighting the urgent need for further attention to water quality safety issues. The conclusions derived from this research provide theoretical support for understanding the long-term evolutionary mechanisms of groundwater in mining areas, while also offering important insights for improving groundwater environmental management and ensuring water resource security in mining regions. Full article

This study evaluated the reliability and application of relative potency factors (RPFs) for assessing hepatic mixture risks of per- and polyfluoroalkyl substances (PFASs) in Korean finished drinking water. A total of 1254 finished water samples collected from 70 drinking water treatment plants between 2018 and 2024 were analyzed for eight PFAS compounds. Hepatic RPFs proposed by the National Institute for Public Health and the Environment (RIVM) were assessed using a structured scoring system and applied to estimate PFOA-equivalent mixture risks. Hazard quotients (HQs) based on hepatic toxicity reference doses were also calculated for comparison. PFAS concentrations generally declined over time, including PFOA from 0.0032 to 0.0014 μg/L, PFOS from 0.0008 to 0.0003 μg/L, and PFHxS from 0.0072 to 0.0004 μg/L between 2018 and 2024. The RPF-based method produced higher cumulative risk estimates than the individual toxicity-based approach, suggesting that single-compound HQs may underestimate risks from co-occurring PFASs. Although total risks were generally below the non-carcinogenic threshold of 1.0, the 95th percentile PFOA-equivalent risk for PFNA exceeded the individual threshold of 0.1. These findings support endpoint-specific RPF-based assessment for PFAS mixtures in drinking water. Full article

Population growth, climate change, pollution, and prolonged droughts are contributing to increasing water scarcity, which poses a significant challenge to global sustainable water management. Among the available adaptation strategies, potable water reuse has emerged as a viable and increasingly adopted solution in areas facing water stress. This review examines evolution, regulatory frameworks, treatment technologies, and implementation strategies related to drinking water reuse worldwide. Through the historical review, it becomes clear that the idea of water reuse has deep roots (5000 years ago), while the analysis of modern legislative and intergovernmental approaches led to the conclusion that the rules governing water reuse vary depending on the country and are in most cases quite strict (e.g., the Urban Wastewater Treatment Directive (UWWTD) and the Water Framework Directive). To make potable water reuse possible, including direct and indirect systems, advanced wastewater treatment technologies are applied, among which membrane processes and advanced oxidation processes (AOPs) are most often chosen, while treatment trains are almost always used. The recent studies of potable water reuse presented highlight the interest of both the scientific community and the state. The economic review demonstrates that potable water reuse can be economically viable and more economical than other solutions, e.g., desalination. The review identifies the key challenges (technical, economic, institutional, and social) and opportunities for scaling up potable water reuse as a primary water supply option and discusses its potential role in enhancing long-term sustainable water management, especially in areas that are either arid or semi-arid. Full article

Type 2 diabetes (T2D) is a chronic metabolic disorder leading to increased cardiovascular risk and vascular dysfunction. Hyperglycemia, a hallmark of T2D, drives hypercontractility, thereby compromising vascular function. Heat shock protein 70 (HSP70) has emerged as an important player in vascular reactivity under physiological conditions via its interaction with calcium mobilization, and in T2D, blocking this protein prevents hypercontractility. Circulating extracellular HSP70 (eHSP70) has also been proposed as a biomarker in chronic diseases, as it can function as a damage-associated molecular pattern (DAMP) to activate the innate immune system and promote low-grade inflammation. Berberine (BBR), a natural alkaloid with anti-inflammatory properties, has been shown to attenuate vascular contraction by modulating intracellular calcium handling. Yet the link between HSP70 and BBR in modulating vascular contraction in T2D remains unknown. Therefore, we investigated whether acute and/or chronic BBR treatment modulates HSP70 to prevent vascular hypercontractility in the T2D mouse model. For acute ex vivo treatment, db/+ and db/db aortic rings were incubated for 30 min with or without the HSP70 inhibitor VER155008, in the presence or absence of BBR or vehicle. For chronic in vivo treatment, db/+ and db/db mice received intraperitoneal BBR injections (10 mg/kg, 3 times per week) and BBR in their drinking water (0.5 mg/mL) for 28 days. Following chronic (4 weeks, in vivo) or acute ex vivo (30 min) BBR treatment, vascular function was assessed in aortic rings isolated from male T2D (db/db) and age-matched non-diabetic (db/+) mice using wire myography. Rings were incubated with or without the HSP70 inhibitor VER155008, in the presence or absence of BBR or vehicle. Overt hyperglycemia and hypercontractility were observed in diabetic animals compared with non-diabetic controls. While acute BBR treatment attenuated vasoconstriction in both diabetic and nondiabetic groups, the combination of BBR and VER155008 produced a stronger inhibitory effect only in the diabetic group. Chronic BBR treatment prevented aortic hypercontractility in diabetic mice; however, the synergistic effect with VER155008 was no longer observed. Additionally, BBR reduced systemic HSP70 levels. Collectively, these findings indicate that BBR improves vascular smooth muscle cells’ function in T2D, at least in part, through HSP70-dependent mechanisms during chronic treatment. Full article

Background/Objectives: Hepatic fibrosis is a progressive pathological condition characterized by excessive extracellular matrix deposition in the liver, which may progress to cirrhosis and liver failure. Short-chain fatty acids (SCFAs) have demonstrated anti-inflammatory and anti-fibrotic properties; however, their therapeutic potential in hepatic fibrosis remains incompletely understood. This study aimed to evaluate the effects of acetate, propionate, and butyrate on carbon tetrachloride (CCl₄)-induced hepatic fibrosis in Balb/C mice. Methods: Hepatic fibrosis was induced in Balb/C mice using CCl₄, and the animals were treated with acetate, propionate, or butyrate administered via drinking water for four weeks. Biochemical parameters, histological alterations, and the expression of fibrogenic and inflammatory markers were evaluated and compared with a silymarin-treated group. Results: Treatment with SCFAs significantly reduced serum transaminase levels (AST and ALT) compared to the untreated fibrotic group. Histological analyses demonstrated the preservation of hepatic architecture and reduced inflammatory infiltrates, particularly in the butyrate-treated group. In addition, SCFAs significantly decreased the gene and protein expression of fibrogenic markers (ACTA2 and COL1A1) and inflammatory markers (NOS1, NF-κB, and IL-10), with propionate showing the most pronounced effects. Overall, the therapeutic effects observed with SCFAs were comparable or superior to those obtained with silymarin treatment. Conclusions: The findings suggest that SCFAs, especially butyrate and propionate, exert hepatoprotective, anti-inflammatory, and anti-fibrotic effects in CCl₄-induced hepatic fibrosis. These compounds represent promising therapeutic candidates for the treatment of liver fibrosis. Full article

Groundwater quality in arid and semi-arid regions is increasingly affected by salinization, evaporation, abstraction, and agricultural return flow. This study evaluates the hydrochemical evolution, isotopic characteristics, ²²²Rn activity, and water-use suitability of groundwater and associated waters in Karbala Governorate, central Iraq. Seventeen groundwater, lake water, and municipal supply water samples were analyzed for physicochemical parameters, major ions, δ¹⁸O, δ²H, and ²²²Rn. Hydrochemical, isotopic, and water-quality assessment methods were applied to evaluate groundwater evolution, salinization, and suitability for drinking and irrigation. The waters are near-neutral, with pH values of 6.18–7.35, but are strongly mineralized. Electrical conductivity ranges from 1440 to 16,305 µS/cm, and total dissolved solids (TDS) range from 592 to 10,191 mg/L. Most samples belong to a Ca–Mg–SO₄–Cl facies, indicating sulfate- and chloride-rich hard water evolution. The highest mineralization occurs near Karbala proper and lake-influenced sites. Ion ratios and chloro-alkaline indices indicate that evaporite dissolution, gypsum/anhydrite dissolution, carbonate interaction, evaporation, and local ion exchange jointly control groundwater chemistry. Stable isotopes indicate meteoric origin with variable evaporative enrichment; however, highly saline but isotopically depleted water, particularly W8, shows that evaporation alone cannot explain salinization. ²²²Rn activities range from below detection to 11.28 Bq/L and mainly reflect local aquifer contact and degassing. High TDS, sulfate, chloride, and very high hardness limit suitability for drinking-water use. For irrigation, the sodium hazard is low, but salinity, hardness, magnesium hazard, and permeability constraints make most samples unsuitable or restricted. Management should prioritize salinity and hardness control, treatment or blending before domestic use, restricted irrigation of the least saline wells under drainage and soil-salinity monitoring, protection of less mineralized recharge zones, and long-term monitoring of lake-adjacent and agriculturally influenced wells. Full article

Access to safe drinking water remains a global public health concern due to its role in the transmission of infectious diseases. Despite the 20th-century achievement of chlorine-based disinfection, drinking water systems face threats from aging infrastructure, climate-induced stressors, and emerging pathogens that evade traditional treatment. This bibliometric review maps three decades of research on microbial contamination in drinking water systems to explain its historical developments, current knowledge, and important updates. Only original and review articles retrieved on 13 April 2026 were screened for inclusion, requiring a focus on detecting, monitoring, or mitigating microbial contamination in drinking water systems. Analysis of 93 records identified a linear growth pattern, shifting from acute enteric pathogen monitoring to the management of opportunistic pathogens (OPs), antimicrobial resistance (AMR), and disinfection by-products (DBPs). Additionally, traditional fecal indicator bacteria (FIB), such as Escherichia coli, may not fully predict the presence of resilient pathogens protected within biofilms or free-living amoebae (FLA), which serve as environmental reservoirs for infection. To address these limitations, this review presents a conceptualization of waterborne pathogens by proposing formal case definitions and diagnostic criteria for critical contamination events (CCE) and chronic low-level exposure (CLLE). Lastly, knowledge gaps and open research questions relevant to future studies on microbial contamination in drinking water systems were identified and discussed. Full article

The progressive deterioration of surface water quality due to natural and anthropogenic factors, together with the limitations associated with conventional chemical coagulants, has driven the development of natural coagulants as sustainable alternatives for water treatment. In this context, the present study analyzed the production and application of a chitosan-based natural coagulant obtained from Oreochromis niloticus fish scales through a chemical method. The first phase involved biopolymer extraction through depigmentation, deproteinization, demineralization, and deacetylation; the second phase evaluated its performance as a coagulant using jar tests with water from the Magdalena River; and the third phase consisted of statistical analysis of the results using ANOVA. Yields of 78%, 78.20%, 88.52%, and 30% were obtained for each processing stage, and the chitosan achieved a degree of deacetylation of 76.87%, confirming its potential for water treatment applications. Optimal conditions were determined as a coagulant dosage of 300 mg/L and a flocculation time of 30 min, while ANOVA results indicated that both variables significantly influenced turbidity removal (p < 0.05). Under these conditions, a turbidity reduction of 76.30% was achieved. However, the final turbidity and color values did not meet Colombian regulatory standards, which was attributed to the presence of residual minerals and a moderate degree of deacetylation. Overall, the results demonstrate that chitosan derived from fish scales represents a sustainable alternative to chemical coagulants; however, process optimization and complementary treatment stages are required to meet drinking water standards. Full article

Trihalomethanes (THMs) are priority disinfection by-products in drinking water, and their effective removal remains a persistent challenge for sustainable treatment. Here, olive mill solid waste (OMSW) was valorized into biochar (BC) and evaluated as a low-cost adsorbent for chloroform, bromodichloromethane (BDCM), chlorodibromomethane (CDBM), and bromoform under environmentally relevant conditions. Among the prepared materials, thermally activated BC (BC-T) performed best, achieving equilibrium removals of 74.7 ± 6.6% for chloroform, 91.1 ± 0.8% for BDCM, 87.2 ± 1.9% for CDBM, and 93.8 ± 0.3% for bromoform at 3000 mg/L. Adsorption increased with bromine substitution, following the order of bromoform > CDBM ≈ BDCM > chloroform, consistent with rising hydrophobicity. In contrast, KOH and Zn/Fe activation increased the BET surface area but did not improve THM removal, suggesting that adsorption was controlled by surface chemistry and site accessibility rather than surface area alone. Persulfate (PSF) addition reduced THM removal, indicating that oxidant activation did not compensate for the loss of adsorption capacity. Adsorption data were well described by the Freundlich isotherm and pseudo-second-order kinetics. BC-T also maintained high removal efficiency in drinking water, demonstrating its promise as a practical polishing adsorbent for THM control and as a route for high-value valorization of an abundant agricultural residue. Full article

Ketoprofen (KET) is a non-steroidal anti-inflammatory drug frequently detected in surface waters and effluents, with the potential to impact trophic base organisms. This study evaluated the toxicity of KET, in its active pharmaceutical ingredient (API) form and in four commercial formulations (KET-1, KET-2, KET-3, and KET-4), on two freshwater species: the cyanobacterium Microcystis novacekii and the microalga Chlorella vulgaris. Cell growth assays, performed under acute (4 days) and chronic (14 days) conditions, showed that the API KET was the most toxic compound, especially for M. novacekii, with a chronic EC50 of 1.35 mg/L. The commercial formulations presented distinct toxicity profiles, suggesting the influence of excipients and synergistic or antagonistic interactions. For C. vulgaris, low acute toxicity was observed, with increased chronic effects at high concentrations and possible hormetic response at low doses. Risk quotient (RQ) calculations, based on environmental concentrations of KET, indicated low risk in surface and drinking water, but high risk in untreated hospital and wastewater treatment plant effluents, especially for M. novacekii. The results show that the complete formulation, exposure time, and target species are critical factors in the ecotoxicological risk assessment of pharmaceuticals in freshwater environments. Full article

The valorization of drinking water treatment sludge (DWTS) and eggshell waste represents a promising route for reducing landfill disposal and developing alternative stabilized materials for geotechnical applications. This study aimed to evaluate the mechanical and microstructural behavior of DWTS stabilized with commercial lime (CL) and eggshell-derived hydrated lime (EHL), including alkali-activated EHL systems. EHL was produced from locally collected eggshell waste through washing, drying, grinding, calcination at 1000 °C for 4 h, hydration, drying, and sieving. The mixtures were prepared with lime contents of 5%, 8%, 11%, and 14%, while NaOH solutions of 0.5, 1.0, and 1.5 M were used for the activated systems. A total of 120 cylindrical specimens were compacted under controlled dry unit weight and moisture content and cured for 7 and 28 days. The stabilized DWTS was evaluated through unconfined compressive strength (q_u), SEM–EDS analysis, and multifactorial ANOVA. The highest q_u for CL-treated specimens was 4561.72 kPa at 14% lime and 28 days, while EHL reached its best response at 11% lime and 7 days, with a q_u of 3195.13 kPa. In general, EHL showed a competitive performance at intermediate and high lime contents, although increasing NaOH molarity tended to reduce strength. Full article

Background: Access to safe drinking water remains a critical public health concern in rural Ghana, particularly in climatically vulnerable and underserved settings. This study assessed the microbiological and chemical quality of drinking water and evaluated nitrate-related health risks in the North Gonja and North-East Gonja Districts of the Savannah Region. Methods: A cross-sectional study was conducted between January and March 2025. A total of 460 water samples were collected from groundwater sources and household storage containers. Microbial analyses targeted total coliforms and Escherichia coli. Physicochemical and chemical parameters included nitrate-nitrogen, pH, residual chlorine, major ions, and trace metals. Data was analyzed using descriptive statistics, chi-square tests, spatial interpolation, and non-carcinogenic health risk assessment based on the hazard quotient (HQ) approach. Results: Widespread microbial contamination was observed, with 91.5% of household water samples positive for total coliforms and 46.6% for E. coli. Contamination of source water was significantly higher in North Gonja than in North-East Gonja. Overall, 49.1% (n = 55) of groundwater sources exceeded the World Health Organization guideline value for nitrate-nitrogen, with exceedances predominantly occurring in North Gonja. Additionally, 67.0% (n = 75) of samples were outside the acceptable pH range (6.5–8.5), including 74 samples below 6.5 and one above 8.5. Residual chlorine was not detected in any of the samples. Health risk assessment indicated potential non-carcinogenic risks associated with nitrate exposure, particularly among infants and children. Conclusions: The study demonstrates significant microbial contamination and nitrate-related health risks in the study area, particularly in North Gonja. Interventions such as improved source protection, routine water quality monitoring, chlorination, household water treatment, and implementation of Water Safety Plans are recommended to enhance drinking water safety and reduce associated public health risks. Full article

Microfiltration membranes are widely used in drinking water treatment due to their high efficiency. However, long-term operation of polymeric membranes may lead to deterioration of hydraulic properties as a result of fouling and material aging. This study aims to determine the impact of long-term aging on hydraulic permeability and separation properties, and to determine the lifespan of microfiltration polyvinylidene fluoride (PVDF) membranes. The practical and industrial novelty of this study lies in providing an authentic, 11-year operational baseline for a full-scale microfiltration system treating highly variable surface water. The study evaluates membranes installed in a full-scale plant in Jarosław (Poland), treating surface water from the San River. The system includes 120 PVDF capillary modules (0.1 μm). After 11 years, the membranes maintained very high separation efficiency, ensuring almost complete removal of turbidity and microorganisms. However, membrane resistance increased nearly threefold, while permeability decreased by about 86%. Maintaining capacity required a gradual increase in transmembrane pressure. The permeability loss exceeded the commonly accepted replacement threshold of 70%, suggesting that membrane replacement after more than a decade of operation is technically and economically justified. Full article

Urban water insecurity is an increasingly critical challenge in rapidly urbanizing regions of the Global South, driven by population growth, environmental degradation, infrastructure limitations, and institutional constraints. Kathmandu Valley, Nepal, exemplifies these interconnected pressures. This study presents a systematic review of 45 peer-reviewed and selected grey literature sources published between 2000 and 2025, conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were included if they examined drinking water contamination, public health risks, household coping practices, wastewater-related exposure, or governance dynamics in Kathmandu Valley, Nepal. Findings were synthesized using a narrative thematic approach. The review identifies widespread contamination across municipal supply systems, groundwater, tanker water, traditional water sources, and household-stored water. Microbial contamination, particularly total coliforms, fecal coliforms, and Escherichia coli, emerged as the most consistently reported and immediate public health concern. Chemical and physicochemical contaminants, including ammonia, iron, arsenic, nitrate, and turbidity, were also widely reported, especially in shallow and deep groundwater systems. Seasonal dynamics further influenced exposure risks, with increased microbial contamination during monsoon periods and greater dependence on alternative and less regulated water sources during dry seasons. The findings further indicate that unsafe water exposure is associated with a substantial burden of waterborne diseases and emerging risks such as antimicrobial resistance. Although household water treatment practices reduced contamination in some cases, risks often persisted due to recontamination during storage and handling. These burdens disproportionately affected marginalized and peri-urban populations with limited access to safe and reliable water infrastructure. The review also highlights persistent governance challenges, including institutional fragmentation, weak regulatory enforcement, inadequate infrastructure investment, and growing dependence on informal water supply systems. Together, these conditions contribute to a hybrid urban water system in which formal and informal sources coexist without consistent quality control. Overall, the evidence demonstrates that water insecurity in Kathmandu Valley is a systemic condition shaped by the interaction of environmental contamination, unequal exposure, household coping limitations, and fragmented governance. By integrating environmental, public health, and governance evidence, this review advances understanding of urban water insecurity in rapidly urbanizing contexts and highlights the need for integrated, equity-oriented, and governance-informed interventions. These findings have broader relevance for cities across the Global South experiencing similar environmental and infrastructural pressures. Full article