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Search Results (1,147)

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Keywords = ICP-OES

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22 pages, 1379 KB  
Article
Multielement Analysis of Selected Superfood Seeds and Grains Using ICP-OES: Sources of Essential and Toxic Elements
by Elżbieta Maćkiewicz, Piotr Wysocki and Małgorzata Iwona Szynkowska-Jóźwik
Molecules 2026, 31(9), 1374; https://doi.org/10.3390/molecules31091374 - 22 Apr 2026
Abstract
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 [...] Read more.
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
(This article belongs to the Special Issue Modern Trends and Solutions in Analytical Chemistry in Poland)
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17 pages, 1907 KB  
Article
Geochemical Fractionation and Environmental Risk Assessment of Potentially Toxic Elements in Copper Flotation Tailings from Tongling, Anhui Province
by Yunhu Hu, Shuwen Xue, Mu You and Hongxia Fang
Molecules 2026, 31(8), 1349; https://doi.org/10.3390/molecules31081349 - 20 Apr 2026
Abstract
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 [...] Read more.
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
(This article belongs to the Section Analytical Chemistry)
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16 pages, 3536 KB  
Article
Innovation and Sustainable Tailing Management: Technological and Mineralogical Characterization of Rock Powder from the São Paulo Aggregate Industry for Potential Reuse
by Ana Olivia Barufi Franco-Magalhães, Fabiano Cabañas Navarro, Rogério Pinto Ribeiro and Jacqueline Zanin Lima
Sustainability 2026, 18(8), 3932; https://doi.org/10.3390/su18083932 - 15 Apr 2026
Viewed by 221
Abstract
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 [...] Read more.
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
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17 pages, 2535 KB  
Article
Analytical Identification and Quantification of Phosphogypsum in Epoxy Resin Composites
by Jiangqin Wang, Xuehang Chen, Jiangang Zhang, Wanliang Yang and Tianxiang Li
Inorganics 2026, 14(4), 113; https://doi.org/10.3390/inorganics14040113 - 14 Apr 2026
Viewed by 161
Abstract
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 [...] Read more.
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
(This article belongs to the Special Issue Multifunctional Composites and Hybrid Materials)
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23 pages, 568 KB  
Article
Influence of Diet on Bioaccessibility of Iron from Dietary Supplements and Medicinal Products—Results of In Vitro Digestion Model and Analytical Determinations
by Piotr Bawiec, Agnieszka Jaworowska, Jan Sawicki, Marcin Czop, Joanna Tokarczyk, Paweł Helon and Wojciech Koch
Nutrients 2026, 18(8), 1219; https://doi.org/10.3390/nu18081219 - 13 Apr 2026
Viewed by 306
Abstract
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 [...] Read more.
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
(This article belongs to the Special Issue Iron Supplements and Intestinal Health)
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24 pages, 5219 KB  
Article
From Farm to Table and Back Again: Circular Valorization of Biomass Ash and Sewage Sludge into Sustainable Material Blends
by Ekaterina Serafimova, Vilma Petkova and Veneta Petkova
Materials 2026, 19(8), 1552; https://doi.org/10.3390/ma19081552 - 13 Apr 2026
Viewed by 324
Abstract
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 [...] Read more.
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
(This article belongs to the Special Issue Novel Functional Materials for Electronics and Biomedicine)
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11 pages, 1194 KB  
Brief Report
Sodium Retention and Distribution in Growing and Adult Rodents Fed High and Low Salt Diets
by Christina Vialva, Sisi Cao, Song Yue, Linda H. Nie, Cheryl A. M. Anderson and Connie M. Weaver
Nutrients 2026, 18(8), 1212; https://doi.org/10.3390/nu18081212 - 11 Apr 2026
Viewed by 371
Abstract
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 [...] Read more.
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
(This article belongs to the Section Micronutrients and Human Health)
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20 pages, 881 KB  
Article
Characterization of Residual Woody Biomass for the Production of Densified Solid Biofuels and Their Local Utilization
by Mario Morales-Máximo, Ramiro Gudiño-Macedo, José Guadalupe Rutiaga-Quiñones, Juan Carlos Coral-Huacuz, Luis Fernando Pintor-Ibarra, Luis Bernardo López-Sosa and Víctor Manuel Ruíz-García
Fuels 2026, 7(2), 23; https://doi.org/10.3390/fuels7020023 - 10 Apr 2026
Viewed by 372
Abstract
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 [...] Read more.
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 article belongs to the Special Issue Biofuels and Bioenergy: New Advances and Challenges)
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21 pages, 2745 KB  
Article
Geopolymer-Based Solution for the Stabilization of Iron Ore Tailings Byproduct
by Gabriella Melo de Deus Vieira, Roberto Aguiar dos Santos, Matheus Navarra Satuf Muniz, Átila Geraldo Rochido dos Santos, José Wilson dos Santos Ferreira and Michéle Dal Toé Casagrande
Polymers 2026, 18(8), 914; https://doi.org/10.3390/polym18080914 - 9 Apr 2026
Viewed by 476
Abstract
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 [...] Read more.
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
(This article belongs to the Section Polymer Applications)
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20 pages, 362 KB  
Article
Bioaccumulation of Macro- and Microelements, Including Potentially Toxic Metals(loid)s, in Pods and Leaves of Vigna unguiculata L. Walp. Cultivated in a Contaminated Area
by Letícia Rosa de Moraes Borges, Alessandro Carvalho da Fonseca, Elaine Silva de Pádua Melo, Rosângela dos Santos Ferreira, Aline Carla Inada, Rita de Cássia Avellaneda Guimarães, Priscila Aiko Hiane, Valter Aragão do Nascimento and Karine de Cássia Freitas
Sci 2026, 8(4), 83; https://doi.org/10.3390/sci8040083 - 7 Apr 2026
Viewed by 328
Abstract
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 [...] Read more.
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
33 pages, 3328 KB  
Article
Multiyear Soil–Fruit Transfer Dynamics of Macro- and Trace Elements in Raspberry (Rubus idaeus L.) Under Field Conditions
by Ionela Ramona Zgavarogea, Nadia Paun, Claudia Sandru, Violeta-Carolina Niculescu, Ana Maria Nasture, Augustina Mirabela Pruteanu, Irina-Aura Istrate and Oana-Romina Botoran
Plants 2026, 15(7), 1107; https://doi.org/10.3390/plants15071107 - 3 Apr 2026
Viewed by 370
Abstract
Understanding the soil–plant transfer of both essential and non-essential elements is crucial for evaluating the crop nutritional quality, environmental interactions, and food safety. This study delivered a multiyear and multielement assessment under field conditions of the element uptake, translocation, and accumulation in raspberry [...] Read more.
Understanding the soil–plant transfer of both essential and non-essential elements is crucial for evaluating the crop nutritional quality, environmental interactions, and food safety. This study delivered a multiyear and multielement assessment under field conditions of the element uptake, translocation, and accumulation in raspberry (Rubus idaeus L.), based on data collected over two growing seasons (2024–2025) in two contrasting Romanian agroecosystems. Two commercial cultivars (Opal and Delniwa) were investigated under fertilized and unfertilized conditions. The concentrations of essential macroelements such as Ca, Mg, Na, and K, as well as trace elements (Li and Sr), were determined in soils and fruits using ICP-OES and AAS. The soil–fruit transfer was quantified through the transfer factor, assisted by a robust statistical framework which integrated spatial–temporal variability and non-parametric analysis. The results highlighted two contrasting accumulation regimes. The essential macroelements revealed a dynamic uptake pattern driven by the physiological demand, soil availability, and fertilization. K exhibited the highest transfer capacity, while Ca had a restricted translocation to the fruits, due to the intrinsic transport limitations. On the other hand, Li and Sr revealed a constrained accumulation, characterized by low concentrations, weak responsiveness to fertilization, and a strong dependence on the soil geochemical background and interannual dilution processes. The spatial variability between the cultivation sites and year-to-year changes in the dilution intensity was evidenced as the dominant driver of the transfer efficiency, while the varietal differences had a secondary but detectable role, mainly for the Ca–Sr discrimination. Overall, the results evidenced that the multielement accumulation in the raspberries was governed by the interplay between the soil geochemistry, physiological transport constraints, and environmental variability. Furthermore, the research provided a field-based, multiyear evidence supporting improved soil management, cultivar selection, as well as the strategies that may increase the fruit nutritional quality while minimizing the trace element risks. Full article
(This article belongs to the Section Plant–Soil Interactions)
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18 pages, 4030 KB  
Article
Alkaline Decomposition Kinetics in Ca(OH)2 Medium of Mercury Jarosite
by Sayra Ordoñez, Rubén H. Olcay, Francisco Patiño, Hernán Islas, J. Eliecer Méndez, Mizraim U. Flores, Iván A. Reyes, Miriam Estrada and Miguel Pérez
Toxics 2026, 14(4), 293; https://doi.org/10.3390/toxics14040293 - 28 Mar 2026
Viewed by 536
Abstract
Mercury in jarosites is crucial for environmental management and metallurgy. These minerals can incorporate highly toxic heavy metals from mining waste into their structure. This study analyzes the decomposition of mercury jarosite in a Ca(OH)2 medium, focusing on its topological, kinetic, and [...] Read more.
Mercury in jarosites is crucial for environmental management and metallurgy. These minerals can incorporate highly toxic heavy metals from mining waste into their structure. This study analyzes the decomposition of mercury jarosite in a Ca(OH)2 medium, focusing on its topological, kinetic, and modeling characteristics. Topological analysis, XRD and SEM−EDS were performed. ICP−OES was used to analyze the mercury and sulfur ions diffusing from the mercury jarosite into the Ca(OH)2 solution. The kinetic model that best fit the data was that of spherical particles of constant size with an unreacted core under chemical control. The XRD results did not show new crystallographic phases. SEM−EDS showed a partially decomposed particle indicating a halo and core. The experimental conditions included temperatures from 298.15 to 333.15 K, concentrations of 0.0071–0.23210 mol L−1 Ca(OH)2, particle diameters of 25–53 µm, and pH of 11.12–12.85. During the induction period, reaction orders of 1.04 and 0.44 were obtained, along with an activation energy of 77.580 kJ mol−1. For the progressive conversion period, the reaction orders were 0.59 and 0.15, with an activation energy of 52.124 kJ mol−1. The overall kinetic modeling showed favorable results, supporting the evolutionary process of the mercury jarosite decomposition reaction in an alkaline medium under different conditions. This allows prediction of when mercury could be released back into the environment in alkaline soils or lime barriers. Full article
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17 pages, 592 KB  
Article
Hair Manganese as a Marker of Cardiometabolic Status Rather than Coronary Artery Disease Severity—An Exploratory Pilot Study
by Ewelina A. Dziedzic, Aleksandra Czernicka, Agnieszka Mazur-Jax, Andrzej Osiecki, Jakub S. Gąsior, Jakub Marek Baran, Łukasz Dudek and Wacław Kochman
Nutrients 2026, 18(7), 1089; https://doi.org/10.3390/nu18071089 - 28 Mar 2026
Viewed by 358
Abstract
Background: Manganese (Mn) is an essential trace element with antioxidant properties; however, excessive exposure may contribute to inflammation and vascular dysfunction. Hair analysis provides an indicator of long-term Mn exposure. This study evaluated the relationship between hair Mn levels, acute coronary syndrome (ACS), [...] Read more.
Background: Manganese (Mn) is an essential trace element with antioxidant properties; however, excessive exposure may contribute to inflammation and vascular dysfunction. Hair analysis provides an indicator of long-term Mn exposure. This study evaluated the relationship between hair Mn levels, acute coronary syndrome (ACS), coronary artery disease (CAD) severity, and cardiovascular risk factors, with particular emphasis on metabolic status in a cardiometabolic population. Methods: Hair Mn concentration was measured using inductively coupled plasma optical emission spectrometry (ICP-OES) in 80 patients (mean age 67 ± 11 years; 28.8% women) undergoing coronary angiography for suspected ACS. Final diagnoses included stable CAD (N = 42) and ACS [ST-elevation myocardial infarction (STEMI) N = 17, non-ST-elevation myocardial infarction (NSTEMI) N = 12, and unstable angina (UA) N = 9]. CAD severity was quantified using the SYNTAX score and the Coronary Artery Surgery Study Score (CASSS). Associations with clinical variables were assessed using non-parametric tests and Spearman correlations. The median SYNTAX score was 13.8 (range 0.0–68.5), and the median hair Mn concentration was 0.22 ppm (range 0.01–1.65). Results: SYNTAX scores were higher in ACS than in stable CAD (p = 0.027), with the highest values observed in NSTEMI. Hair Mn levels did not differ among diagnostic groups and showed no association with CASSS or SYNTAX (R = −0.11; p = 0.348). No differences were detected with respect to sex, smoking, prior myocardial infarction, hypertension, hyperlipidemia, or type 2 diabetes. A modest inverse correlation was observed between hair Mn and body mass index (BMI) in unadjusted analysis (R = −0.25; p = 0.03), but this association was not robust after correction for multiple comparisons, suggesting a potential exploratory link between manganese homeostasis and cardiometabolic status. Conclusions: Although hair Mn concentration was not associated with angiographic indices of CAD severity or ACS subtypes, the observed relationship with BMI may indicate a role of Mn homeostasis in cardiometabolic regulation. Larger prospective studies are required to clarify these associations. Full article
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34 pages, 3023 KB  
Article
Thermochemical Valorisation of Apple Pomace-Derived Biochar: Temperature-Driven Structural Evolution, Soil Chemical Modulation, and Agronomic Performance in Wheat Germination
by Ramona-Raluca Handolescu, Violeta-Carolina Niculescu, Nadia Paun, Claudia Sandru, Antoaneta Roman, Daniela Ion-Ebrasu and Sina Niculina Cosmulescu
Appl. Sci. 2026, 16(7), 3273; https://doi.org/10.3390/app16073273 - 28 Mar 2026
Viewed by 369
Abstract
Apple pomace represents an important agro-industrial residue with high moisture content and significant environmental burden if improperly managed. This study investigated its thermochemical valorisation into biochar via two processes, followed by comprehensive physicochemical characterization and agronomic evaluation. Elemental analysis revealed carbon enrichment from [...] Read more.
Apple pomace represents an important agro-industrial residue with high moisture content and significant environmental burden if improperly managed. This study investigated its thermochemical valorisation into biochar via two processes, followed by comprehensive physicochemical characterization and agronomic evaluation. Elemental analysis revealed carbon enrichment from 47.89% in raw material to 77–78% after the thermal process, evidencing a progressive aromatization. Scanning electron microscopy, Fourier transform infrared spectroscopy, and Raman analysis confirmed a temperature-dependent transition from partially amorphous carbon (400 °C) to more ordered aromatic structures (450 °C), while excessive thermal treatment (550 °C) increased structural defects. ICP-OES revealed an enrichment in thermally stable metals (Fe, Al, Mn) and limited Cd accumulation. Germination assays using Triticum aestivum L. demonstrated that biochar produced at 400 °C significantly improved the germination uniformity and seedling height (14.1 mm), as well as biomass accumulation compared to the control soil sample. The fertilizer addition increased the soluble Na and electrical conductivity (up to 643 µS/cm), potentially inducing transient salinity stress. Soil chemical analysis indicated increased K availability in soils amended with biochar produced at 400 °C, whereas the combination of biochar obtained at 450 °C with fertilizer conducted to elevated concentrations of certain trace metals, mainly Ni and Cr, highlighting the demand for careful monitoring. Overall, the biochar produced at 400 °C yielded to an optimal balance between structural stability, nutrient enrichment, and agronomic performance, evidencing that apple pomace may be a viable feedstock for sustainable biochar production within circular bioeconomy frameworks. Full article
(This article belongs to the Special Issue Technical Advances in Biomass Conversion)
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16 pages, 1400 KB  
Article
Toxic Metal Content in Mexican Propolis: A Human Health Risk Assessment
by Ana Paola Balderrama-Carmona, Leticia García-Rico, Ana Lilia López-Duarte, Melissa Valenzuela-Rincón, Luis Gerardo Ochoa-Balderrama, Guadalupe González-Ochoa, Lilian Karen Flores-Mendoza, Mario Eduardo Almada-Ortiz, Edgar Felipe Moran-Palacio and María Mercedes Meza-Montenegro
Foods 2026, 15(7), 1128; https://doi.org/10.3390/foods15071128 - 25 Mar 2026
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Abstract
In the present study, arsenic, cadmium, lead, and manganese contamination in propolis was assessed. A total of 12 raw propolis samples were analysed using atomic emission spectrometry with inductively coupled plasma (ICP-OES) for each of the metals. The analyses revealed that the samples [...] Read more.
In the present study, arsenic, cadmium, lead, and manganese contamination in propolis was assessed. A total of 12 raw propolis samples were analysed using atomic emission spectrometry with inductively coupled plasma (ICP-OES) for each of the metals. The analyses revealed that the samples were contaminated with each of the following metals: arsenic (ranging from <0.21 to 0.4 ppm), cadmium (<0.008 to 0.123 ppm), lead (0.580 to 117.01 ppm), and manganese (4.22 to 47.57 ppm). Lead levels exceeded the acceptable limits for consumption. A chemometric characterization was performed, looking at the correlation between elemental contamination, showing high correlation between cadmium and manganese levels (r = 0.80). Furthermore, the samples with the highest contamination levels were in areas with high industrial and agricultural activity. A risk assessment for toxic metals indicated a risk associated with lead. While the amount of lead present in the propolis samples was deemed to pose a low carcinogenic risk, it is noteworthy that the levels of the other metals detected do not pose any discernible health risk associated with the consumption of propolis. This conclusion is crucial for understanding the safety profile of propolis as a dietary supplement or natural product. Full article
(This article belongs to the Section Food Toxicology)
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