Search Results (2,702)

Corrosion of refractory materials in NaCl–KCl melts is a major issue affecting the service life of linings in aluminum metallurgy, where these salts serve as the basis for covering and refining mixtures. The aim of this study was to comprehensively evaluate the corrosion resistance of alumina-silicate refractory materials (ASRM) with a high SiO₂/Al₂O₃ ratio in contact with melts of varying NaCl–KCl ratios. Static crucible corrosion tests were conducted in accordance with the technical specification CEN/TS 15418:2006. Macro- and microscopic analysis, chemical analysis (AAS), and semi-quantitative EDX analysis enabled detailed monitoring of the depth of melt infiltration, microstructural changes, and element distribution within the material. The results demonstrated that as the NaCl content in the melt increased, there was a significant rise in both the depth of infiltration and the degree of material degradation. A linear regression model confirmed a very strong positive correlation between NaCl content and the extent of damage (R² = 0.967). Chemical analysis revealed that the silicon content decreases in the infiltrated zone, while aluminum remains stable, indicating superior corrosion resistance of Al₂O₃ compared to SiO₂. EDX analysis also confirmed increased concentrations of sodium and chlorine in the infiltrated areas, complementing the AAS results and providing more precise mapping of the distribution of corrosion products within the material structure. These findings provide a quantitative basis for optimizing the composition of refractory materials and designing protective strategies to extend their service life under the aggressive operating conditions of aluminum production. Full article

This study examined the spatial and seasonal variations of trihalomethanes (THMs) and estimated the health risks associated with THM exposure in drinking water through various pathways. Water samples were collected from 14 distribution districts connected to the Ulutan Distribution System (UDS) and the Süleyman Bey Distribution System (SDS), which supply drinking water to Zonguldak Province, Türkiye. THMs were measured using the USEPA 551 method. The median total trihalomethanes (TTHMs) ranged from 41 μg/L to 71 μg/L, which is below the Turkish drinking water standard of 100 μg/L. Chloroform (TCM) was the most common trihalomethane in all distribution networks in UDS and SDS. On the other hand, pre-ozonation oxidation after chlorination in SDS disinfection caused the contribution of brominated THMs (62%) to THM formation to be higher than that of TCM (38%). The study on cancer risk reveals that ingestion (96%) poses the greatest risk of the investigated pathways, followed by dermal contact (3.95%), while inhalation has been found to have a negligible effect. The highest and lowest median TTHMs occurred during winter and summer. The findings of the study show that the distribution areas of Kozlu, Ömerli, Topçalı, and Uzunçayır, for both genders, exhibit an unacceptable cancer risk level according to the criteria established by the USEPA (˃10⁻⁴). Bromodichloromethane (BDCM) and chlorodibromomethane (DBCM) are the main contributors to cancer risk for males and females in UDS and SDS. The hazard index (HI) data indicated that the HI value remained below one for both UDS and SDS. Sensitivity analysis of THMs demonstrated that exposure frequency (EF) was the primary parameter contributing to the maximum potential impact on the total cancer risk exposure frequency (EF), followed by body weight (BW) and exposure duration (ED). Further, the results provide valuable information for health departments and water management authorities, enabling the formulation of more specific and efficient policies to minimise THM levels in drinking water distribution networks. Full article

In the pursuit of novel anticancer therapies, assessing their selectivity and safety profile towards healthy cells is crucial. This study investigated chlorochalcones, derivatives of 2′-hydroxychalcone containing a chlorine atom, for their impact on human breast cancer cells (MCF-7 and MDA-MB-231), healthy blood cells (erythrocytes, peripheral blood mononuclear cells (PBMCs), platelets), and microvascular endothelial cells (HMEC-1). Our findings demonstrated that chlorochalcones did not detrimentally affect erythrocytes, showing no hemolysis or preserving osmotic resistance and transmembrane potential. They also exhibited minimal impact on normal PBMC viability and varying effects on platelet metabolic activity at therapeutic concentrations. Importantly, these derivatives displayed lower toxicity towards HMEC-1 endothelial cells than towards breast cancer cells, indicating a degree of selectivity. Chlorochalcones have high antiproliferative activity against cancer cells, primarily by inducing apoptosis with virtually no significant impact on cell cycle progression. Their mechanism of action involves the modulation of reactive oxygen species (ROS) levels and induction of mitochondrial dysfunction, including membrane depolarization and reduced mitochondrial mass. Biological activity, including toxicity and ROS modulation, is dependent on the position and number of chlorine atoms. In conclusion, this study highlights the ability of chlorochalcones to effectively target malignant cells while sparing normal circulatory and endothelial cells, thus positioning them as a promising class of candidates for further anticancer drug development. Full article

Carbon tetrachloride (CT) is a toxic volatile chlorinated hydrocarbon, posing a serious hazard to ecosystem and human health. This study discussed the bioremediation possibility of groundwater contaminated by CT. Enhanced reductive dechlorination bioremediation (ERD) was used to promote the reductive dechlorination process of CT by adding yeast extract as a supplementary electron donor. The microcosm samples of the Control and Experi group were setup in the experiment, and the CT degradation efficiency and microbial community structure changes over 150 days were monitored. The results showed that the Experi group achieved complete degradation of CT within 40 days, while the control group had no significant change. By analyzing the physical and chemical indexes such as VFAs, sulfate ions, oxidation–reduction potential, pH value and so on, the key changes in the degradation process of CT were revealed. Microbial community analysis showed that specific microorganisms such as Acinetobacter johnsonii, Aeromonas media and Enterobacter Mori played a significant role in the degradation of CT. They may produce hydrogen through fermentation to provide electron donors for the reductive dechlorination of CT. In addition, the genes of reductive dehalogenase synthase related to CT degradation were also identified, which provided molecular evidence for understanding the biodegradation mechanism of CT. The results deliver a scientific basis for optimizing the bioremediation strategy of CT-contaminated groundwater. Full article

In the context of chlorate’s application as a cathodic reagent of power sources, the mechanism of its electroreduction has been studied in electrochemical cells under diffusion-limited current conditions with operando spectrophotometric analysis. Prior to electrolysis, the electrolyte is represented as an aqueous mixed NaClO₃ + H₂SO₄ solution (both components being non-electroactive within the potential range under study), without addition of any external electroactive catalyst. In the course of potentiostatic electrolysis, both the cathodic current and the ClO₂ concentration demonstrate a temporal evolution clearly pointing to an autocatalytic mechanism of the process (regions of quasi-exponential growth and of rapid diminution, separated by a narrow maximum). It has been substantiated that its kinetic mechanism includes only one electrochemical step (chlorine dioxide reduction), coupled with two chemical steps inside the solution phase: comproportionation of chlorate anion and chlorous acid, as well as chlorous acid disproportionation via two parallel routes. The corresponding set of kinetic equations for the concentrations of Cl-containing solute components (ClO₃⁻, ClO₂, HClO₂, and Cl⁻) has been solved numerically in a dimensionless form. Optimal values of the kinetic parameters have been determined via a fitting procedure with the use of non-stationary experimental data for the ClO₂ concentration and for the current, taking into account the available information from the literature on the parameters of the chlorous acid disproportionation process. Predictions of the proposed kinetic mechanism agree quantitatively with these experimental data for both quantities within the whole time range, including the three characteristic regions: rapid increase, vicinity of the maximum, and rapid decrease. Full article

This article presents an innovative method for phosphate(V) removal from industrial wastewater using cerium(III) chloride as a coagulant, integrated with reagent recovery. The process combines coagulation, acid extraction, and multistage recovery of cerium and phosphorus, enabling partial reagent loop closure. Based on our previously published studies, at an optimised dose (81.9 mg Ce³⁺/L), phosphate(V) removal reached 99.86% and total phosphorus (sum of all phosphorus forms as elemental P), 99.56%, and 99.94% of the added cerium was retained in sludge. Reductions were also observed for TSS (96.67%), turbidity (98.18%), and COD (81.86%). The sludge (101.5 g Ce/kg, 22.2 g P/kg) was extracted with HCl, transferring 99.6% of cerium and 97.5% of phosphorus to the solution. Cerium was recovered as cerium(III) oxalate and thermally decomposed to cerium(IV) oxide. Redissolution in HCl and H₂O₂ yielded cerium(III) chloride (97.0% recovery and 98.6% purity). The HCl used for extraction can be regenerated on-site from chlorine and hydrogen obtained from gas streams, improving material efficiency. Life cycle assessment (LCA) showed environmental benefits related to eutrophication reduction but burdens from reagent use (notably HCl and oxalic acid). Although costlier than conventional precipitation, this method may suit large-scale applications requiring high phosphorus removal, low sludge, and alignment with circular economy goals. Full article

Background: Rational dietary patterns and adequate nutritional status support athlete health and performance, while unhealthy habits may impair these outcomes. This study aimed to identify dietary patterns among Polish professional athletes using a food frequency questionnaire and assess their correlations with nutritional status indicators. Methods: Participants included 226 elite Polish athletes (aged 16–39 years; 87 women, 139 men) from various sports disciplines. Dietary intake was assessed using a food frequency questionnaire, and dietary patterns were identified through principal component factor analysis. Nutritional status was evaluated using anthropometry, bioelectrical impedance, and selected blood biochemical markers. Spearman’s rho correlations were applied to explore associations between dietary patterns and nutritional status. Results: Eight dietary patterns were identified: ‘High-fat’, ‘Sweets and beverages’, ‘Potentially rational’, ‘Vegetables and fruits’, ‘Meat and flour’, ‘Low-fat’, ‘Dairy’, and ‘Juices’. Of the two patterns considered unhealthy, ‘High-fat’ was associated with anthropometric indices—positively with the slenderness index and negatively with body mass index, particularly among men. Positive correlations with favorable nutritional indicators were observed for the ‘Vegetables and fruits’ pattern (arm muscle circumference, BMI, serum uric acid, hydration status), ‘Low-fat’ (body fat percentage), ‘Dairy’ (serum creatinine), and ‘Juices’ (serum creatinine, total protein, chlorine, uric acid). Conclusions: Our findings suggest that the identified dietary patterns are original and specific to Polish professional athletes. Determining the relationships between nutritional factors and anthropometric and biochemical indices may inform dietary modifications among athletes to ensure optimal nutritional status. Full article

Poly(methyl methacrylate) (PMMA) and its composites are widely used in industrial applications; therefore, their durability is of great concern. In this study, the photooxidative degradation behavior of nanosilica-filled PMMA composite films and the cooperative effect of mixed solvents containing tetrahydrofuran (THF) and chloroform (TCM), as well as interfacial functional groups, was investigated. The surface functional groups of nanosilica fillers, such as polar, aryl, and alkyl moieties, significantly affect the photodegradation kinetics and pathways for PMMA. The key process lies in the modulation of solvent–solvent reaction selectivity at the polymer–filler interface. Functional groups that selectively promote the chlorination reaction between THF and TCM accelerate PMMA photodepolymerization, while those that suppress this reaction hinder degradation. This interfacial effect is validated by trends in molecular weight loss, volatile product profiles, and MMA yields during aging. Our findings reveal that the photodegradation behavior of PMMA composites is not only governed by environmental conditions but also critically influenced by interfacial chemistry. In this way, this study provides novel insight into the interfacial aging process for polymer nanocomposites, as well as guidance for the rational design of PMMA-based materials with improved durability. Full article

The present study reports the sono-chemical synthesis of novel nanosized Cr(III), Mn(II), and Pd(II) complexes incorporating the chloro-2-(quinolin-8-yliminomethyl)-phenol imine ligand. The synthesized complexes were characterized using various spectroscopic and analytical techniques, including Fourier-transform infrared (FT-IR) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). The results confirmed the successful coordination of the ligand-to-metal centers, forming stable nanosized metal complexes with distinct physicochemical properties. Biological evaluations, including antimicrobial and antioxidant assays, revealed that the synthesized complexes exhibited enhanced biological activity compared to the free ligand, demonstrating potent antibacterial and antifungal properties against various pathogenic strains. The potential of the complexes to serve as efficient free-radical inhibitors was determined by employing DPPH radical scavenging assays, which underscored their significant antioxidant properties. Furthermore, molecular docking studies were conducted to elucidate the binding interactions of the metal complexes with biological targets, providing insights into their mechanism of action. The findings suggest that the synthesized nanosized Cr(III), Mn(II), and Pd(II) complexes possess promising biological properties, making them potential candidates for pharmaceutical and biomedical applications. The study also demonstrates the effectiveness of sono-chemical synthesis in producing nanosized metal complexes with enhanced physicochemical and biological characteristics. Full article

The advancement of catalytic materials is critical to improving the performance, reducing the cost and enhancing the sustainability of Proton Exchange Membrane (PEM) fuel cells and electrolyzers. Although Platinum Group Metal (PGM)-based electrocatalysts exhibit high electrochemical activity, their limited availability and the environmentally intensive extraction pose significant challenges. This study aims to demonstrate the direct reuse of recycled impure platinum (Pt) precursors for the synthesis of effective Pt/C electrocatalysts as a viable step toward circular hydrogen economy implementation. A low-cost and eco-friendly chlorine-based hydrometallurgical method was successfully employed to recycle over 99% of Pt from End-of-Life (EoL) Membrane Electrode Assemblies (MEAs), with an industrial perspective. Recycled metal precursor was used without purification to synthesize Pt/C electrocatalyst via a scalable and sustainable method. The catalyst was structurally and chemically characterized, and their electrochemical performance towards the Oxygen Reduction Reaction (ORR) was conducted under conditions simulating real operating environments. The recycled-metal-derived catalyst demonstrated comparable activity toward ORR (170 A/gPt) relative to a commercial catalyst, indicating its potential as viable alternative to conventional PGM-based catalysts. By integrating energy-efficient recycling with advanced material design, this work supports the development of cost-effective and green solutions for clean energy technologies aligned with a circular hydrogen economy model. Full article

Metal halide perovskites have appeared as a promising semiconductor for high-efficiency and low-cost photovoltaic technologies. However, their performance and long-term stability are dramatically constrained by defects at the surface and grain boundaries of polycrystalline perovskite films formed during the processing. Herein, we propose a defect-targeted passivation strategy using 2-chlorocinnamic acid (2-Cl) to simultaneously enhance the efficiency and stability of perovskite solar cells (PSCs). The crystallization kinetics, film morphology, and optical and electronic properties of the used formamidinium–cesium lead halide (FA_0.85Cs_0.15Pb(I_0.95Br_0.05)₃, FACs) absorber were modulated and systematically investigated by various characterizations. Mechanistically, the carbonyl group in 2-Cl coordinates with undercoordinated Pb²⁺ ions, while the chlorine atom forms Pb–Cl bonds, effectively passivating the surface and interfacial defects. The optimized FACs perovskite film was incorporated into inverted (p-i-n) PSCs with a typical architecture of ITO/NiO_x/PTAA/Al₂O₃/FACs/PEAI/PCBM/BCP/Ag. The optimal device delivers a champion power conversion efficiency (PCE) of 22.58% with an open-circuit voltage of 1.14 V and a fill factor of 82.8%. Furthermore, the unencapsulated devices retain 90% of their initial efficiency after storage in ambient air for 30 days and 83% of their original PCE after stress under 1 sun illumination with maximum power point tracking at 50 °C in a N₂ environment, demonstrating the practical potential of dual-site molecular passivation for durable perovskite photovoltaics. Full article

In this study, non-isothermal pyrolysis of a mixture of disposable surgical face masks (FMs) and nitrile gloves (NGs) was conducted, using a heating rate of 100 °C/min, N₂ flowrate of 100 mL/min, and temperatures between 500 and 800 °C. Condensable product yield peaked at 600 °C (76.9 wt.%), with gas yields rising to 31.0 wt.%, at 800 °C. GC-MS of the condensable product confirmed the presence of aliphatic compounds (>90%), while hydrogen, methane, and ethylene dominated the gas composition. At 600 °C, gasoline (C₄ to C₁₂)-, diesel (C₁₃ to C₂₀)-, motor oil (C₂₁ to C₃₅)-, and heavy hydrocarbon (C₃₅₊)-range compounds accounted for 23.7, 46.7, 12.5, and 17.1%, of the condensable product, respectively. Using model-free methods, the average activation energy and pre-exponential factor were found to be 309.7 ± 2.4 kJ/mol and 2.5 ± 3.4 × 10²⁵ s⁻¹, respectively, while a 2-dimensional diffusion mechanism was determined. Scale-up runs confirmed high yields of condensable product (60–70%), with comparable composition to that obtained from lab-scale tests. The pyrolysis oil exceeds acceptable oxygen, nitrogen, chlorine, and fluorine levels for industrial steam crackers—needing pre-treatment—while other contaminants like sulphur and metals could be managed through mild blending. In summary, this work offers a sustainable approach to address the environmental concerns surrounding disposable FMs and NGs. Full article

Ensuring the safe reuse or discharge of treated wastewater is critical to achieving environmental sustainability, particularly in regions facing growing water stress. This study introduces a biological approach using Bacillus thuringiensis (Bt) biofilm formation as an indicator of treated wastewater quality from three wastewater treatment plants (WWTPs) in Deep East Texas. Treated wastewater samples were collected from chlorine and sulfur dioxide treatment stages at WWTPs in Nacogdoches, San Augustine, and San Jacinto counties. We assessed biofilm development through optical density and scanning electron microscopy (SEM) and evaluated changes in key anions (F⁻, Cl⁻, NO₂⁻, Br⁻, NO₃⁻, PO₄³⁻, and SO₄²⁻) using ion chromatography (IC). A two-tailed Student’s t-test was used to evaluate statistical significance (p ≤ 0.05). Remarkably, biofilm formation occurred in all samples, including those treated with chemical disinfectants, suggesting that microbial activity can still occur post-disinfection. Ion shifts, particularly the depletion of F⁻, NO₃⁻, and SO₄²⁻ and the release of Cl⁻, NO₂⁻, and PO₄³⁻, highlighted active microbial processes. These findings suggest that Bt biofilms can serve as sensitive, low-cost tools to monitor treated wastewater, offering critical insights into potential reuse risks and supporting more sustainable water management. Full article

Optical sensors have emerged as a popular technology for sensing biological and chemical analytes in various fields, including environmental monitoring, toxicology, disease/infection screening, and food processing, due to their ease of use, high sensitivity, and specificity. In this study, we introduce ColorX, an ultra-portable and smart spectrophotometric device based on a commercially available fitness tracker. ColorX exploits the in-built LEDs and photodiodes of a fitness tracker for wavelength-specific absorption measurements and can be controlled wirelessly using a companion smartphone app. The device’s raw data are transmitted via Bluetooth and stored on the app for analysis and data visualisation. We validated the performance of ColorX against a standard benchtop spectrophotometer by experimentally testing five different measurements related to water quality: nitrite (>0.07 mg/L, %avgCV: 1.06)), sulphate (>18 mg/L, %avgCV: 0.39), chromium (>0.002 mg/L, %avgCV: 0.51), free chlorine (>0.005 mg/L, %avgCV: 0.68), and turbidity (>2.97 NTU, %avgCV: 1.04). Our results showed that ColorX had comparable performance to the benchmark spectrophotometer (R² values > 0.9 in all cases). Due to its ultra-portability, water-proof design, wireless control, and smartphone-aided data analysis, we believe ColorX will be highly beneficial for a wide range of on-field spectrophotometric applications. Our work demonstrates the potential of frugal science to develop affordable and accessible technology for optical sensing. Full article

The transition towards renewable energy necessitates large-scale, cost-effective energy storage solutions. Carnot Batteries (CBs), which store electricity as thermal energy, offer potential advantages for medium-to-long-duration storage, including geographical flexibility and lower energy capacity costs compared to electrochemical batteries. This article examines the evolution and current state-of-the-art of CB technologies, including Pumped Thermal Energy Storage (PTES) and Liquid Air Energy Storage (LAES), discussing their performance metrics, techno-economics, and development challenges. Concurrently, the increasing generation of biomass ash (BA) from bioenergy production presents a waste valorization challenge. This article critically evaluates the potential of using BA, particularly from woody biomass, as an ultra-low-cost thermal energy storage (TES) medium within CBs systems. We analyze BA’s typical composition (SiO₂, CaO, K₂O, etc.) and relevant thermal properties, highlighting significant variability. Key challenges identified include BA’s likely low thermal conductivity, which impedes heat transfer, and poor thermal stability (low ash fusion temperatures, sintering, corrosion) due to alkali and chlorine content, especially problematic for high-temperature CBs. While the low cost is attractive, these technical hurdles suggest direct use of raw BA is challenging. Potential niches in lower-temperature systems or as part of composite materials warrant further investigation, requiring detailed experimental characterization of specific ash types. Full article