Search Results (1,152)

Pyrolysis liquid (PL) derived from biomass pyrolysis exhibits biopesticidal properties and represents a promising value-added product within the sustainable circular economy framework. However, knowledge about the antimicrobial potential of PLs produced from walnut residue at different pyrolysis temperatures remains limited. We investigated the chemical composition and antimicrobial activity of PLs obtained from agricultural walnut residue (Juglans regia L.) against selected plant pathogenic bacteria and fungi. PLs were produced at four temperature ranges: 200–300 °C (W-1), 300–400 °C (W-2), 400–500 °C (W-3), and 500–600 °C (W-4). Chemical characterization was performed using Gas chromatography–mass spectrometry (GC-MS), High-performance liquid chromatography (HPLC), and Inductively coupled plasma optical emission spectrometry (ICP-OES), with determination of total phenolic and flavonoid contents. Pyrolysis temperature significantly influenced the chemical profile and bioactive compound content of the PLs, with W-4 showing the highest total phenolic and flavonoid levels. Heavy metal analysis indicated minimal contamination in all samples. Antibacterial activity was observed in stock solutions, whereas diluted applications showed limited effects. The W-4 fraction showed the strongest antibacterial activity and exhibited MIC values of 12.50 µL/mL against Clavibacter michiganensis subsp. michiganensis, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. syringae, and 25.00 µL/mL against Erwinia amylovora. Antifungal activity differed markedly across temperature ranges, with W-3 and W-4 displaying superior activity against Fusarium oxysporum and Verticillium dahliae, achieving complete mycelial growth inhibition at 5%, compared to 10% for W-2 and 20% for W-1. Positive controls confirmed assay validity (ciprofloxacin for antibacterial assays and cycloheximide for antifungal assays), whereas negative controls showed no inhibitory effect. Overall, higher pyrolysis temperatures, particularly 400–600 °C, enhanced the antimicrobial potential of walnut residue-derived PLs, supporting their possible use as bio-based antifungal agents for sustainable crop protection. Full article

Knowledge of the heterogeneous composition of mineral substances and technogenic materials is vital in the development of technological designs and in environmental impact assessments. However, the simultaneous application of analytical methods often reveals discrepancies between different methods that cannot be explained by the commonly used scalar agreement metrics. The current study suggests the possibility of evaluating inter-methodical agreement in the compositional data of heterogeneous substances using the example of lead smelting slag compositional data. The compositional data of 96 samples of lead smelting slag were analyzed using independent methods of XRF, ICP-OES and AAS. The agreement between the obtained results was evaluated at three levels of hierarchy: element-wise bias and dispersion, structured variability between methods and preservation of covariance structure; PCA was used as the tool for the evaluation. High agreement between the ICP-OES and AAS methods was found for the transition metals (r ≈ 0.97–0.99), with negligible bias. The presence of increased dispersion and deviations in the inter-methodical agreement was found in the case of the methods compared with the XRF method, especially for the matrix components such as Si (r ≈ 0.92). Coefficients of variation for metallic elements stay between 12 and 15%, but XRF has shown consistently higher variability for certain elements. PCA results show that despite local differences, the main covariance structure was kept across methods, with the first two components explaining about 40–45% of total variance. These results clearly indicate that high correlation does not necessarily ensure methodological interchangeability. The hierarchical framework proposed here will provide a reproducible basis for cross-method validation and support reliable data integration in complex mineral systems. Full article

The purpose of this work was to synthesize and study catalytic systems based on a carbon-containing support obtained from coke fines from the Shubarkol deposit as a waste product of the coal industry for the processing of phenolic compounds. Based on the obtained carbon sorbent, mono- and binary catalysts with active phases of transition metal oxides (Fe, Co, Ni) were synthesized by wet impregnation, followed by heat treatment at 500–700 °C, as well as the aluminum oxide compositions. The surface morphology and elemental composition of the samples were studied by scanning electron microscopy (SEM) with energy dispersion analysis and elemental mapping (EDS mapping), and the content of active phases was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). The catalytic activity was studied in phenol hydrogenation reactions. The CoO/C catalyst demonstrated the greatest activity, providing a 62.36% benzene yield during phenol hydrogenation. The catalytic activity of the CoO/C catalyst has also been studied in the hydrogenation reactions of structurally and functionally more complex compounds, pyrocatechol and resorcinol. The yield of benzene was 63.16% in the hydrogenation of pyrocatechol and 48.64% in the hydrogenation of resorcinol. It was found that the CoO/C catalyst exhibits the highest efficiency at a temperature of 420 °C, a pressure of 6–6.5 MPa and a reaction duration of 120 min. The results obtained make it possible to evaluate the prospects of using a carbon sorbent obtained from coke fines from the Shubarkol deposit as a support for CoO as part of an active and stable catalytic system designed for deep processing of phenolic compounds. Full article

Carbon monoxide (CO) is a highly toxic, colorless, and odorless gas posing significant risks to human health and the environment. Catalytic oxidation offers a promising, economically viable solution by converting CO into nontoxic CO₂ under mild conditions without energy-intensive regeneration. However, existing MnO₂-based catalysts often exhibit poor activity and stability in harsh environments, particularly at low temperatures and high humidity. In this study, we propose a Cu²⁺ ion-exchange modification strategy to activate lattice oxygen species in δ-MnO₂, thereby significantly enhancing its low-temperature CO oxidation performance. Structural characterization by XRD and SEM confirms that Cu-doped δ-MnO₂ retains its original birnessite-type structure and porous morphology. ICP-OES and XPS analyses verify that Cu²⁺ ions effectively replace interlayer K⁺ ions. The resulting MnO₂-150Cu catalyst demonstrates exceptional activity, achieving 100% CO conversion at 40 °C in dry air and maintaining full conversion at 80 °C in the presence of 1.3 vol.% H₂O at a weight hourly space velocity of 150 L/g·h. H₂-TPR and O₂-TPD results confirm that Cu doping enhances the reducibility and mobility of lattice oxygen. Furthermore, in situ DRIFTS analysis reveals that the migration of active oxygen species is the rate-limiting step at low temperatures. This work provides a novel and effective strategy for activating lattice oxygen in MnO₂-based catalysts, offering a promising pathway for developing high-performance materials for low-temperature CO oxidation under practical environmental conditions. Full article

Objectives: This study characterised the bioactive properties (i.e., ion release, pH rise, and apatite formation) of a newly developed Voco Profluorid + BioMin F varnish. Three additional varnishes were investigated for comparison: Clinpro™ White Varnish (3M™, St. Paul, MN, USA), MI Varnish (GC, Tokyo, Japan), and Profluorid varnish (VOCO GmbH, Cuxhaven, Germany). The Clinpro™ White and MI varnishes were chosen for comparison due to their similar composition of active ingredients. Profluorid served as a standard fluoride-only varnish reference. Methods: Dental varnish ingredients were characterised using ATR-FTIR, XRD, and ¹⁹F and ³¹P MAS-NMR. Coated coverslips were immersed in Tris buffer and artificial saliva (pH 4.0 and 7.0) for 2–24 h. Ion release was analysed using ICP-OES and a fluoride ion-selective electrode whilst monitoring pH changes. Post-immersion, coverslips were analysed by XRD and MAS-NMR to assess possible apatite formation. Results: XRD and ¹⁹F MAS-NMR detected NaF in all four varnishes. BioMin F varnish showed a ³¹P peak matching BioMin F glass, with an additional brushite peak, indicating partial reaction of the bioactive glass (BAG) with rosin resin water. All varnishes released fluoride and calcium, but only BioMin F and MI varnishes released phosphate, which is essential for the formation of calcium fluorapatite. Post-immersion analysis confirmed fluorapatite formation in BioMin F and, to a lesser extent, the Profluorid varnish. No apatite formation was observed in the other two varnishes. MI varnish exhibited calcium fluoride formation before and after immersion, as evidenced by XRD and ¹⁹F MAS-NMR analysis. Conclusions: The novel BioMin F varnish potentially promotes remineralisation by providing a sustained and slow release of therapeutic ions that are essential for the formation of fluorapatite. Full article

The term ‘superfoods’ refers to a rapidly expanding group of food products that have gained increasing global interest due to their high nutritional value and association with health-oriented dietary patterns. Many superfoods, particularly grains and seeds, are rich sources of essential minerals, plant protein, dietary fibre, and bioactive compounds, making them valuable components of gluten-free, vegetarian, and vegan diets. The aim of this study was to evaluate the elemental composition of selected superfood grains and seeds and to verify the reliability of manufacturers’ declarations. The analyses confirmed that the investigated samples possess a rich macro- and trace elemental composition, with pronounced differences among product groups. Based on median concentrations, pumpkin and hemp seeds were characterized by generally high levels of Mg, K, P, Fe, Mn, and Zn, whereas chia seeds exhibited notably elevated Ca content. In contrast, quinoa and amaranth showed comparatively lower elemental concentrations. Most of the results obtained for the analysed products are within the permissible deviation from the value declared on the packaging, as specified in the relevant EU regulations. The presence of potentially toxic elements, including Al, Pb, and Cd, was also detected. Cadmium accumulation was of particular concern in flax seeds, where all samples exceeded the limit of quantification and approached permissible levels. Principal component analysis revealed clear clustering patterns, indicating similarities between amaranth and quinoa, as well as between hemp and pumpkin seeds, while chia and flax seeds formed distinct groups. These results highlight both the nutritional potential of superfoods and the necessity for independent verification of their elemental composition. Full article

Copper flotation tailings are produced in large quantities during ore beneficiation and smelting, yet remain underutilized and can act as persistent sources of potentially toxic elements. Here, we combined XRD-based mineralogical characterization, ICP-OES quantification, Tessier sequential extraction, and pH-dependent batch leaching to elucidate metal occurrence, mobility, and associated ecological risk in tailings from Tongling, Anhui Province. This study systematically analyzed the mineral composition, potentially toxic elements content, chemical fractions, leaching behavior, and ecological risks of copper flotation tailings from the Shuimuchong tailings reservoir in Tongling, Anhui Province. XRD and XRF analyses revealed that calcite, quartz, and garnet were dominant mineral phases in the tailings. Elevated levels of Cu, Cd, Pb, Zn, and As were detected, some of which surpassed both local background concentrations and national soil quality standards. Most potentially toxic elements primarily existed in the residual fraction, indicating low mobility. Leaching experiments revealed that Zn, Cu, and As showed enhanced release under acidic conditions, making them priority risk elements during tailings acidification. Pollution index and ecological risk assessments indicated that the tailings were heavily contaminated, with Cu and Cd as the main risk contributors. The Risk Assessment Code (RAC) evaluation showed that Cd had the highest bioavailability and ecological risk. By clarifying the behavior of pollutants, this study contributes to the effective regulation of environmental hazards and the sustainable use of tailing materials. Full article

Brazilian soils are prone to a gradual decline in fertility due to intensive agricultural activity combined with natural weathering, which increases the demand for chemical fertilizers. Among potential alternatives, soil remineralization using crushed rock is a promising strategy. Silicate agrominerals (SAs) applied as soil remineralizers have attracted attention due to their ability to supply plant-available nutrients while reducing dependence on conventional mineral fertilizers. This study evaluated the potential of residues from six quarries in Brazil as soil remineralizers as a regulatory screening assessment. Samples were subjected to mineralogical, petrological, and chemical characterization using an integrated approach, including X-ray diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), and leaching experiments. XRD analysis revealed that anorthite and augite were the major minerals present in the mining waste. These minerals are less resistant to weathering, which enhances the release of macro- and micronutrients, essential for the development of various crops. Chemically, the samples were dominated by SiO₂, Fe₂O₃, and Al₂O₃, with the sum of bases (K₂O + CaO + MgO) ranging from 11.92% to 16.85%, meeting Brazilian standards for use as a soil remineralizer. Leaching results revealed that pH responses varied significantly among the studied samples for the filler particles, with an alkaline shift reaching values above 9.0 after 72 h. In contrast, the powder particle size samples showed no significant variation between the different materials tested, maintaining nearly constant pH levels throughout the period. This preliminary evaluation demonstrates that mining tailings from Brazilian quarries have potential as a sustainable soil remineralizer. This approach not only offers an alternative for soil fertilization but also promotes waste management and circular economy practices, although further studies are needed to assess long-term effectiveness and safety. Full article

Accurate quantification of phosphogypsum (PG) filler in epoxy composites is essential for quality control and performance optimization. Conventional separation by muffle furnace calcination suffers from slow epoxy decomposition and risks thermal degradation of CaSO₄, leading to inaccurate PG quantification. This study introduces a microwave-assisted separation method that leverages molecular vibration heating to achieve faster heating rates and more uniform temperature distribution, enabling complete epoxy removal while minimizing CaSO₄ decomposition. Comprehensive characterization (X-ray diffraction, XRD; Fourier transform infrared spectroscopy, FT-IR; scanning electron microscopy-energy dispersive spectroscopy, SEM-EDS) confirms the structural integrity of the isolated PG filler. Among five quantification methods evaluated, inductively coupled plasma optical emission spectrometry (ICP-OES) based on sulfur content provides the highest accuracy (spike recovery: 91–99.8%, relative standard deviation, RSD ≤ 4.2%), while gravimetry suffices for single-filler systems. This work establishes a reliable analytical framework for PG characterization in epoxy composites, supporting quality control and resource valorization. Full article

Background/Objectives: Iron is a key micronutrient for the proper growth and development of the organism. The aim of this study was to evaluate the impact of diet type, the chemical form of iron, and the formulation of the pharmaceutical preparation on its relative bioaccessibility from selected dietary supplements and medicinal products. Methods: The research was conducted using a two-stage in vitro digestion model, simulating the physiological processes occurring in the human digestive system and ICP-OES determination of iron. The analytical model used in the study involved homogenates of whole-day dietary rations (basic, standard, and high-residue diets) with the addition of selected dietary supplements or medicinal products. It was demonstrated that iron bioaccessibility was strictly determined by dietary composition and the chemical form of the preparation. Results: In the studies conducted without external supplementation, the highest iron bioaccessibility was observed in the basic diet model (7.96%), and the lowest in the standard diet (4.63%). The highest bioaccessibility value was determined for iron sulfate registered as medicine (12.58%), whereas the lowest was iron lactate (5.25%). The extended-release tablets observed the highest bioaccessibility (19.31%). Conclusions: It was proven that the developed in vitro digestion model may serve as an effective tool for the preliminary assessment of iron bioaccessibility, enabling the optimization of supplementation without ethical barriers. Full article

In the era of increasing generation of various waste streams, the possibility of utilizing them as secondary resources is of utmost importance and fully corresponds to the goals of the circular economy. Industrial residues from the pulp and paper industry, such as biomass combustion ash (FARP) and sludge from industrial wastewater treatment (PPWS), together with natural zeolite as a modifying additive, represent valuable sources enabling their integrated valorization. The present study aims to investigate the potential for their reuse through the development of sustainable material blends. A comprehensive analysis of the chemical composition and morphology of the obtained mixtures was carried out using inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results indicate a tendency for the formation of mineral matrices dominated by calcium–sulfur–oxygen (Ca–S–O) phases, with the presence of calcium sulfate and aluminosilicate structures. The blends are associated with the formation of stable crystalline structures exhibiting potential pozzolanic activity. In this way, carbon is captured and fixed in a stable mineral form. The obtained results suggest the potential of these blends for use in low-carbon systems focused on waste valorization and carbon retention. The materials may be suitable for applications in construction, soil remediation, and environmental technologies, contributing to closing the resource loop “from farm to table and back again”. Full article

Background/Objectives: Previous research demonstrates higher sodium retention with increasing levels of dietary salt in some populations. Our objective was to determine whole-body sodium retention and sodium distribution on high and low salt diets using rodent models. Methods: Whole body retention of orally dosed Na-22, a gamma emitter, was measured in female growing and adult Sprague-Dawley rats on high (3.1% by wt. of diet) and low salt (0.13% by wt. of diet) diets. In a second study, whole-body sodium retention was compared between destructive inductively coupled plasma optical emission spectroscopy (ICP-OES) and neutron activation analysis (NAA) in adult male and female C57BL/6 mice. Results: Whole body retention of Na-22 was not different due to the age of rats on a high salt diet, but rats fed the high salt diet excreted Na-22 much more rapidly than rats fed a low salt diet. In mice, neither sodium retention nor tissue distribution was affected by dietary salt. Bland–Altman analysis indicated overall agreement between NAA and ICP-OES measurements, with observed systematic positive bias. Conclusions: Dietary salt had little effect on retention in normotensive rodents and should be studied in hypertensive models. Full article

The energy utilization of residual woody biomass is a relevant strategy for the decentralized energy transition and local waste management in rural areas. The objective of this study was to characterize (physically, chemically, and energetically) five types of residual biomass: pine branches, huinumo (this material refers to the long, thin pine needles that, after drying and falling, form a layer on the forest floor), cherry branches and leaves, and grass waste generated in the community of San Francisco Pichátaro, Michoacán, Mexico, in order to evaluate its viability for the production of densified solid biofuels. A comprehensive analysis was conducted, including moisture content, higher heating value, proximate characterization, structural chemical analysis (using the Van Soest method), elemental CHONS analysis, ash microanalysis (by ICP-OES), and a multicriteria analysis with normalized energy and compositional indicators. The results showed that huinumo and cherry leaves were the most outstanding biomasses, presenting the highest heating values (20.7 MJ/kg) and low moisture and ash contents. Pine branches obtained the most balanced results, characterized by their equilibrium in fixed carbon and lignin, as well as their low potassium content. The multicriteria analysis showed that there is no absolute optimal biomass; however, it indicates that pine branches and huinumo are the most robust feedstocks for the production of briquettes or pellets. The results confirm the significant technical and environmental potential of local lignocellulosic residues for the production of solid biofuels and for contributing to sustainable energy solutions at the local scale. Full article

This study investigated the development of a perlite waste-based geopolymer for stabilizing iron ore tailings byproduct (IOTB) for geotechnical applications. Mixtures containing 70/30 and 80/20 proportions of byproduct and geopolymer were produced using perlite waste as the precursor and NaOH as the alkaline activator through the one-part method. Raw and geopolymer-stabilized IOTB, air-cured for 7, 14, and 28 days, were evaluated by ICP-OES, XRF, pH, geotechnical characterization, compaction, permeability, SEM, and consolidated drained triaxial tests under confining stresses ranging from 250 to 2000 kPa. The selected mixture presented a maximum dry density of 1.8 g/cm³ and optimum moisture content of approximately 14%. XRD results indicated sodium aluminosilicate phases associated with geopolymerization, with mechanical characteristics comparable to feldspar-type structures, while the pH increased from 6.5 to 12.5. Triaxial tests indicated that elastoplastic behavior persisted regardless of the geopolymer addition; however, SEM images confirmed matrix–particle bonding at grain contacts without significant pore filling. The cohesive intercept increased from 0 kPa in the IOTB to 89.1 kPa and 179.2 kPa after 14 and 28 days of curing, respectively, while the friction angle showed a slight increase of up to 7.7%. Deviatoric stress at failure and energy absorption capacity also increased with curing time. Hydraulically, the permeability coefficient remained within the same order of magnitude (10⁻⁴ cm/s), varying from raw IOTB of 2.73 × 10⁻⁴ cm/s to 3.28 × 10⁻⁴ cm/s after 28 days. These results demonstrated that geopolymer stabilization enhanced mechanical performance without compromising drainage capacity, representing a technically viable and socio-environmentally sustainable solution. Full article

Cowpeas are a legume widely consumed in Brazil. Given this, the objective of this study was to investigate the presence of metals (loids) in pods and leaves of Vigna unguiculata located near a highway with high vehicle traffic and a landfill, and to assess possible risks to human health. Pod and leaf samples were collected at nine points between the highway and the landfill. The elements were analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and quantified. The risk to human health was assessed using risk quotient and risk index values. A quantitative analysis of the chemical elements was also performed using the maximum tolerable intake level. Element concentrations were higher in the leaves than in the pods. The human health risk analysis showed that the average daily consumption of both pods (44 g/day) and leaves (67 g/day) may pose a chronic health risk to adult men and women, due to simultaneous exposure to multiple metals. It was concluded that the plant is contaminated and that its ingestion can cause toxicity, warranting warnings against cultivating areas near anthropogenic activities that may be contaminated with heavy metals, thereby affecting nutritional safety. Full article