Search Results (11,958)

A cobalt-loaded magnetic biochar (Co-MBC) catalyst was synthesized to enhance the removal of metronidazole (MNZ). Study explored the performance and mechanism of MNZ degradation by Co-MBC activated permonosulfate (PMS). Results showed that cobalt oxides were effectively deposited onto the biochar surface, new oxygen functional groups were added to the modified biochar, and the presence of the metallic element Co enhanced the efficiency of PMS activation in the composite. More than 90% of MNZ was removed after 60 min with a catalyst dosage of 0.2 g/L and a PS concentration of 1 mM. After four reuses, Co-MBC still showed excellent catalytic performance to degrade over 75% of MNZ. The reaction system performed well even in the presence of inorganic anions and organic macromolecules. However, the degradation rate was inhibited under alkaline conditions. The quenching experiment indicated that •SO₄⁻, •OH, ¹O₂, and •O₂⁻ synergistically degraded MNZ, and that•SO₄⁻ played a dominant role. LC-MS was applied to assess intermediate degradation products, in which CO₂, H₂O, and NO₃⁻ were the final degradation products, and potential degradation pathways were suggested. In conclusion, Co-MBC was an efficient and stable catalytic material, and its ability to activate PMS was improved to effectively degrade antibiotics, a typical priority pollutant. Full article

Lipids are ubiquitous macromolecules that play essential roles in several metabolic processes in plants, such as primary and secondary metabolism, energy storage, and lipid signaling, also being major constituents of membranes. Considering their importance, lipid contents, proportion, and composition are widely modulated in response to environmental conditions, which is even more important under unfavorable conditions such as abiotic stresses. In recent years, technological advances have allowed for the analysis of the global lipid profile, also known as lipidomics, which has emerged as a powerful tool for the comprehensive analysis of the modulation and roles of lipids under different conditions. This review provides a current overview of plant lipidomics research, covering the different lipid classes found in plants, analytical techniques, and the main lipid-related responses under temperature, water, salt, alkali, heavy metal, nutrient deficiency, light, and oxidative stress. Full article

Iron in soil exists in various valence states and is prone to changes with alterations in soil environmental conditions. Its migration and transformation are crucial for soil formation and understanding soil evolution. This study focuses on Quaternary red soils found in woodland, sparse forest grassland, grassland, and cultivated land located in the semi-humid region of the middle temperate zone. For comparison, buried Quaternary red soil was also examined. A soil reconstruction model was used to quantitatively calculate the variation of different forms of iron in order to analyze various forms of iron composition, migration, and transformation within the soil profile, as well as the evolutionary traits of Quaternary red soils influenced by diverse land use activities. This study found that after exposure and use, iron from the topsoil of buried Quaternary red soil migrated to the subsoil, altering the iron distribution. Free iron and crystalline oxides decreased in the topsoil but increased in specific subsoil layers, with woodland and grassland showing the most significant changes. Silicate-bound iron pooled in the soil weathered to form free iron under different land uses, and poorly crystalline iron oxides transformed into crystalline oxides, with grassland exhibiting the highest transformation intensity. Conversion processes predominated over iron migration in the Quaternary red soils. The evolution of Quaternary red soils can be divided into three stages, marked by changes in iron composition and crystallization due to anthropogenic land use activities. Initially, during 140−94 ka BP, iron composition was stable. Then, between 94–24 ka BP, plant decomposition formed iron–metal complexes, releasing and crystallizing poorly crystalline iron oxides. Finally, from 24 ka BP to the present, anthropogenic activities intensified, increasing the formation and conversion rates of these oxides. This study quantifies iron migration and transformation in Quaternary red soils, providing insights for sustainable soil management, especially in regions where human activities have accelerated iron evolution. Based on these findings, the following policy recommendations are proposed: implement sustainable land use practices, encourage land management strategies that preserve natural vegetation, promote research on soil management techniques, develop and implement regulatory policies, and support educational programs to maintain the health and stability of Quaternary red soils, particularly in regions prone to accelerated iron evolution due to anthropogenic activities. Full article

Incorporating insect meals into poultry diets has emerged as a sustainable alternative to conventional feed sources, offering nutritional, welfare benefits, and environmental advantages. This study aims to monitor and compare volatile compounds emitted from raw poultry carcasses and subsequently from cooked chicken pieces from animals fed with different diets, including the utilization of insect-based feed ingredients. Alongside the use of traditional analytical techniques, like solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS), to explore the changes in VOC emissions, we investigate the potential of S3+ technology. This small device, which uses an array of six metal oxide semiconductor gas sensors (MOXs), can differentiate poultry products based on their volatile profiles. By testing MOX sensors in this context, we can develop a portable, cheap, rapid, non-invasive, and non-destructive method for assessing food quality and safety. Indeed, understanding changes in volatile compounds is crucial to assessing control measures in poultry production along the entire supply chain, from the field to the fork. Linear discriminant analysis (LDA) was applied using MOX sensor readings as predictor variables and different gas classes as target variables, successfully discriminating the various samples based on their total volatile profiles. By optimizing feed composition and monitoring volatile compounds, poultry producers can enhance both the sustainability and safety of poultry production systems, contributing to a more efficient and environmentally friendly poultry industry. Full article

The recycling and recovery of value-added secondary raw materials such as spent Zn/C batteries is crucial to reduce the environmental impact of wastes and to achieve cost-effective and sustainable processing technologies. The aim of this work is to fabricate reduced graphene oxide (rGO)-based sorbents with a desulfurization capability using recycled graphite from spent Zn/C batteries as raw material. Recycled graphite was obtained from a black mass recovered from the dismantling of spent batteries by a hydrometallurgical process. Graphene oxide (GO) obtained by the Tour’s method was comparable to that obtained from pure graphite. rGO-based sorbents were prepared by doping obtained GO with NiO and ZnO precursors by a hydrothermal route with a final annealing step. Recycled graphite along with the obtained GO, intermediate (rGO-NiO-ZnO) and final composites (rGO-NiO-ZnO-400) were characterized by Wavelength Dispersive X-ray Fluorescence (WDXRF) and X-ray diffraction (XRD) that corroborated the removal of metal impurities from the starting material as well as the presence of NiO- and ZnO-doped reduced graphene oxide. The performance of the prepared composites was evaluated by sulfidation tests under different conditions. The results revealed that the proposed rGO-NiO-ZnO composite present a desulfurization capability similar to that of commercial sorbents which constitutes a competitive alternative to syngas cleaning. Full article

Piezoelectric c-axis oriented zinc oxide (ZnO) thin films, from 1.8 up to 6.6 µm thick, have been grown by the radio frequency magnetron sputtering technique onto fused silica substrates. A delay line consisting of two interdigital transducers (IDTs) with wavelength λ = 80 µm was photolithographically implemented onto the surface of the ZnO layers. Due to the IDTs’ split-finger configuration and metallization ratio (0.5), the propagation of the fundamental, third, and ninth harmonic Rayleigh waves is excited; also, three leaky surface acoustic waves (SAWs) were detected travelling at a velocity close to that of the longitudinal bulk wave in SiO₂. The acoustic waves’ propagation in ZnO/fused silica was simulated by using the 2D finite-element method (FEM) technique to identify the nature of the experimentally detected waves. It turned out that, in addition to the fundamental and harmonic Rayleigh waves, high-frequency leaky surface waves are also excited by the harmonic wavelengths; such modes are identified as Sezawa waves under the cut-off, hereafter named leaky Sezawa (LS). The velocities of all the modes was found to be in good agreement with the theoretically calculated values. The existence of a low-loss region in the attenuation vs. layer thickness curve for the Sezawa wave below the cut-off was theoretically predicted and experimentally assessed. Full article

The issue of soil contamination by heavy metals is widely acknowledged. Some plants, including medicinal species like St. John’s wort (Hypericum perforatum L.), exhibit accumulation traits, allowing them to accumulate elevated levels of metals, e.g., cadmium (Cd), within their cells. Selenium (Se) may increase the tolerance of plants to abiotic stress caused by the presence of heavy metal in the environment. Depending on its form (oxidation state, organic/inorganic), Se influences plant growth, secondary metabolite content, and biotic stress, as well as incorporates into shoots, providing economic and health benefits for consumers. So far, there are no data on the influence of organic Se(IV) on plants. Our study aimed to determine the effect of organic Se(IV) on the growth, active compound levels (anthranoids, polyphenols), and ultrastructure of St. John’s wort without and under cadmium stress. The phytochemical analysis and microscopic examination was performed on shoots from different days of St. John’s wort in vitro culture on a few variants of Murashige and Skoog medium with Cd (25 and 400 µM) and/or organic Se (IV). Exposure to Se(IV) did not affect hypericins but increased the polyphenol content in the shoots and the biomass. Se(IV) caused an increase in starch grain number in chloroplasts, whereas Cd exposure resulted in the degradation of the chloroplast structure, increased cell vacuolation, as well as swollen mitochondrial cristae. The addition of Se(IV) to these combinations reduced the degree of degradation and growth inhibition and a high content of Se(IV) in plants was observed. Se(IV) had no impact on Cd content at environmental Cd concentrations, but showed an effect at extremely high Cd concentrations. Thus, organic Se(IV) has a beneficial effect on St. John’s wort growth, polyphenol content, and incorporation in shoots and prevents Cd toxicity. Media enriched with organic Se(IV) have both economic advantages and health benefits due to a higher plant growth rate and increased concentrations of polyphenols with strong antioxidant properties, relatively enriched with Se. However, organic Se(IV) should be used with caution in polluted areas. In perspective, speciation analysis and molecular study are crucial to understand the fate and effect of Se (IV) on plants. Full article

Owing to their structural diversity and mesoporous construction, metal–organic frameworks (MOFs) have been used as templates to prepare mesoporous metal oxides, which show excellent performance as anode materials for lithium-ion batteries (LIBs). Co-ZnO/C and Co-Co₃O₄/C nanohybrids were successfully synthesized based on a precursor of Co-doped MOF-5 by accurately controlling the annealing temperature and atmosphere. Experimental data proved that their electrochemical performance was closely associated with the material phase, especially for Co-ZnO/C, indicating that carbon skeleton materials can maintain a good restoration rate of over 99% after undergoing high-current density cycling. Meanwhile, Co-Co₃O₄/C nanohybrids showed an exceedingly high reversible capacity of 898 mAh∙g⁻¹ at a current density of 0.1 C after 100 cycles. Their improved coulombic efficiency and superior rate capability contribute to a mesoporous structure, which provides pathways allowing for rapid Li⁺ diffusion and regulates volume change during charge and discharge processes. Full article

Our preliminary study identified dairy cow placenta extract (CPE) as a mixture of peptides with potent antioxidant activity both in vivo and in vitro. However, the specific antioxidant peptides (AOPs) responsible for this activity were not yet identified. In the current study, we employed virtual screening and chromatography techniques to isolate two peptides, ANNGKQWAEVF (CP1) and QPGLPGPAG (CP2), from CPE. These peptides were found to be less stable under extreme conditions such as high temperature, strong acid, strong alkali, and simulated digestive conditions. Nevertheless, under normal physiological conditions, both CP1 and CP2 exhibited significant antioxidant properties, including free-radical scavenging, metal chelating, and the inhibition of lipid peroxidation. They also up-regulated the activities of intracellular antioxidant enzymes in response to hydrogen-peroxide-induced oxidative stress, resulting in reduced MDA levels, a decreased expression of the Keap1 gene and protein, and increased levels of the Nrf2 and HO-1 genes and proteins. Furthermore, CP1 demonstrated superior antioxidant activity compared to CP2. These findings suggest that CP1 and CP2 hold potential for mitigating oxidative stress in vitro and highlight the efficacy of virtual screening as a method for isolating AOPs within CPE. Full article

In recent years, coal-type critical metal deposits have become a research hotspot in coal geology. As a major coal-accumulating basin in the Xinjiang area, the Turpan-Hami Basin contains abundant coal resources and has the potential to become a large coal-type critical metal deposit. However, previous studies on the enrichment characteristics of critical metal elements in coal are few and need further research. Based on SEM-EDS, XRF, and ICP-MS experiments, this study investigates the coal petrology, mineralogy, and geochemistry of the No. 22 coal of the Xishanyao Formation from the Dananhu Coal Mine, Xinjiang, to identify the sediment source, depositional environment, and controlling factors of the critical metal elements of the No. 22 coal. The results showed that the Dananhu coals are characterized by a low ash yield, low total sulfur content, high volatile yield, and high inertinite proportions. Quartz, kaolinite, and illite are the main minerals in the coal. Compared with the world’s low-rank coals, Ni, Co, Mo, and Ta are slightly enriched, Li, Rb, Cs, Ba, Tl, Bi, and Ge are depleted, and the concentrations of other trace elements are comparable to the average values of the world’s low-rank coals. The REY of the Dannanhu coals exhibited high fractionation, with its enrichment patterns characterized by the H-type and M-H-type. Although most of the critical metals are not enriched in the Dannanhu coals, the Ga, Zr (Hf), and Nb (Ta) concentrations in the coal ash of the Dannanhu coals have reached the economic cut-off grade and have the potential to be a substitute for rare metal resources. The terrigenous detrital sources of the Dannanhu coals mainly come from the Paleozoic dacite, andesite, and a small amount of granite from the Harik Mountain and Eastern Bogda Mountain in the Turpan-Hami Basin. The Dannanhu coals are generally in a dry and hot depositional environment, with high salinity and weak reduction-oxidation. The low source input and weak reduction-oxidation environment have resulted in low concentrations of critical metal of the No. 22 coal from the Dananhu Coal Mine. Full article

CO₂ mineral carbonation is an important method to sequester carbon dioxide (CO₂) in the form of stable mineral carbonates for permanent storage. The slow kinetics of carbonation, especially for iron-rich olivine, is the major challenge for potential application. This work proposes methods to accelerate the mineral carbonation process of different materials in the general mineral grouping of divalent metals–olivine for simultaneous nickel and cobalt recovery. It is found that nickel-olivine is facile for mineral carbonation compared to ferrous and magnesium olivine. Ferrous olivine is the most difficult form of olivine to carbonate as illustrated in both thermodynamics and experimental test results. The increase in iron content in olivine inhibits the CO₂ mineral carbonation process by forming an iron-silica-rich passivation interlayer. The use of a reducing gas or reagent can enhance the mineral carbonation of olivine probably through hindering oxidation of Fe(Ⅱ). The addition of sodium nitrilotriacetate (NTA) as a metal complexing agent is much more efficient for the acceleration than usage of a reducing atmosphere. The combination of sodium bicarbonate/CO₂ gas supply and NTA can enhance the diffusion of all divalent metal ions from the reacting olivine surface, thereby limiting the formation of the passivation interlayer. Meanwhile, highly selective nickel and cobalt leaching can be simultaneously achieved along with the CO₂ mineral carbonation, 94% nickel, and 92% cobalt leaching as well as 47% mineral carbonation versus only 10% iron and 1% magnesium leached in 2 h. This work provides a novel direction to achieve critical metals recovery with accelerated mineral carbonation process. Full article

Cotton textiles improved with metal oxide nanoparticles acquire additional features that may enhance their action against antimicrobial-resistant pathogens due to the unique properties and characteristics of the nanoparticles. The main objective of this work is to evaluate the antimicrobial features of two-sided-coated cotton textiles with ZnO nanoparticles. Nanoparticles were deposited using green chemistry technology with low-temperature oxygen plasma. ZnO particles formed stable structures on textile fibers. The optimal deposition parameters (150 W plasma power, 120 min immersion time) achieved the best effects against Gram-negative and Gram-positive bacteria and microscopic fungi. Two-sided-coated cotton with ZnO nanoparticles showed high antibacterial action on Gram-negative and Gram-positive bacteria. Modification with zinc oxide inhibited the growth of Candida albicans by more than half. Full article

The carbon nanotube cold cathode has important applications in the X-ray source, microwave tube, neutralizer, etc. In this study, the characteristics of carbon nanotube (CNT) electron gun in series with metal-oxide-semiconductor field-effect transistor (MOSFET) were studied. CNTs were prepared on a stainless steel substrate by chemical vapor deposition and assembled with a mesh gate to form an electron gun. The anode current of the electron gun can be accurately regulated by precisely controlling the MOSFET gate voltage in the subthreshold region from 1 to 40 µA. The current stability measurements show the cathode current fluctuation was 0.87% under 10 h continuous operation, and the corresponding anode current fluctuation was 2.3%. The result has demonstrated that the MOSFET can be applied for the precise control of the CNT electron gun and greatly improve current stability. Full article

Extensive research on transition metal perovskite oxides as electrodes in solid oxide cells (SOC) has highlighted the potential ability of Fe-based perovskite oxides to catalyze oxygen reduction/evolution reactions (ORR/OER). The layered perovskite-type system YSr₂Cu₂FeO_7+δ has been reported to possess attractive electrocatalytic properties. This work applies density functional theory (DFT) calculations to investigate oxygen ion diffusion in the YSr₂Cu₂FeO_7+δ system. For δ = 0.5, it is found that in the most stable configuration, the oxygen vacancies in the FeO_1+δ plane are arranged to form Fe ions in tetrahedral, square pyramid, and octahedral coordination. Ab initio molecular dynamics (AIMD) simulations for YSr₂Cu₂FeO_7.5 (δ = 0.5) yield an oxygen ion diffusion coefficient of 1.28 × 10⁻⁷ cm²/s at 500 °C (Ea = 0.37 eV). Complementary results for YSr₂Cu₂FeO_7.2 (δ = 0.2) and YSr₂Cu₂FeO_7.75 (δ = 0.75) indicate that the oxygen diffusion occurs in the FeO_1+δ plane, and depends on the oxygen vacancies distribution around the Fe centers. Full article

Mesoporous silica SBA-15 has emerged as a promising adsorbent and separation material due to its unique structural and physicochemical properties. To further enhance its performance, various surface modification strategies, including metal oxide and noble metal incorporation for improved catalytic activity and stability, organic functionalization with amino and thiol groups for enhanced adsorption capacity and selectivity, and inorganic–organic composite modification for synergistic effects, have been extensively explored. This review provides a comprehensive overview of the recent advances in the surface modification of SBA-15 for adsorption and separation applications. The synthesis methods, structural properties, and advantages of SBA-15 are discussed, followed by a detailed analysis of the different modification strategies and their structure–performance relationships. The adsorption and separation performance of functionalized SBA-15 materials in the removal of organic pollutants, heavy metal ions, gases, and biomolecules, as well as in chromatographic and solid–liquid separation, is critically evaluated. Despite the significant progress, challenges and opportunities for future research are identified, including the development of low-cost and sustainable synthesis routes, rational design of SBA-15-based materials with tailored properties, and integration into practical applications. This review aims to guide future research efforts in developing advanced SBA-15-based materials for sustainable environmental and industrial applications, with an emphasis on green and scalable modification strategies. Full article