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Search Results (199)

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Keywords = peeling reaction

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13 pages, 2442 KB  
Article
Sustainable Green Synthesis of Fe3O4 Nanocatalysts for Efficient Oxygen Evolution Reaction
by Erico R. Carmona, Anandhakumar Sukeri, Ronald Nelson, Cynthia Rojo, Arnoldo Vizcarra, Aliro Villacorta, Felipe Carevic, Ricard Marcos, Bernardo Arriaza, Nelson Lara, Tamara Martinez and Lucas Patricio Hernández-Saravia
Nanomaterials 2025, 15(17), 1317; https://doi.org/10.3390/nano15171317 - 27 Aug 2025
Viewed by 357
Abstract
This work focuses on the sustainable green synthesis of magnetic iron oxide nanoparticles (Fe3O4NPs) using bioreductants derived from orange peel extracts for application in the efficient oxygen evolution reactions (OER). The synthesized catalysts were characterized using X-ray diffraction analysis, [...] Read more.
This work focuses on the sustainable green synthesis of magnetic iron oxide nanoparticles (Fe3O4NPs) using bioreductants derived from orange peel extracts for application in the efficient oxygen evolution reactions (OER). The synthesized catalysts were characterized using X-ray diffraction analysis, field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV–visible spectroscopy. The Fe3O4NPs exhibit a well-defined spherical morphology with a larger Brunauer–Emmett–Teller surface area and a significant electrochemically active surface area. The green synthesis using orange peel extracts leads to an excellent electrocatalytic activity of the apparent spherical Fe3O4NPs (diameter of 9.62 ± 0.07 nm), which is explored for OER in an alkaline medium (1.0 M KOH) using linear-sweep and cyclic voltammetry techniques. These nanoparticles achieved a benchmark current density of 10 mA cm−2 at a low overpotential of 0.3 V versus RHE, along with notable durability and stability. The outstanding OER electrocatalytic activity is attributed to their unique morphology, which offers large surface area and an ideal porous structure that enhances the adsorption and activation of reactive species. Furthermore, structural defects within the nanoparticles facilitate efficient electron transfer and migration of these species, further accelerating the OER process. Full article
(This article belongs to the Special Issue Hydrogen Production and Evolution Based on Nanocatalysts)
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14 pages, 1991 KB  
Article
Construction of a Bin Genetic Map and QTL Mapping of Red Skin in Interspecific Pear Population
by Xiaojie Zhang, Mengyue Tang, Jianying Peng, Hui Ma and Yuxing Zhang
Horticulturae 2025, 11(8), 994; https://doi.org/10.3390/horticulturae11080994 - 21 Aug 2025
Viewed by 220
Abstract
Red epicarp in pears is an important trait for breeding. Exploring the genes regulating pear anthocyanin synthesis and developing molecular markers associated with these traits are important for obtaining new varieties of red pears. We performed whole-genome resequencing (WGS) on 127 ‘Yuluxiang ( [...] Read more.
Red epicarp in pears is an important trait for breeding. Exploring the genes regulating pear anthocyanin synthesis and developing molecular markers associated with these traits are important for obtaining new varieties of red pears. We performed whole-genome resequencing (WGS) on 127 ‘Yuluxiang (Pyrus bretschneideri)’ × ‘Xianghongli (Pyrus communis)’ F1 populations and identified a total of 510,179 single-nucleotide polymorphism (SNP) sites in the population. In total, 1972 bins were screened to form a high-density genetic map with a total map length of 815.507 cM, covering 17 linkage groups with an average genetic distance of 0.414 cM between markers. Three red skin quantitative trait loci (QTLs), located on LG4 and LG5, that explained 18.7% of the phenotypic variance, were detected. The QTL intervals contained 1658 genes, including 94 transcription factors (TF), subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Four key candidate genes (Pspp.Chr05.01969, Pspp.Chr05.01908, Pspp.Chr05.02419, and Pspp.Chr04.01087) that may play a role in promoting pear anthocyanin synthesis were screened and identified by a quantitative polymerase chain reaction (qPCR). Overall, our study deepens our understanding of the genetics of red peel traits in pears and accelerates pear breeding. Full article
(This article belongs to the Special Issue Color Formation and Regulation in Horticultural Plants)
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18 pages, 2295 KB  
Article
The Potential of Waste-Derived Sorbents for Absorbing Petroleum Substances in Firefighting Operations
by Justyna Gniazdowska, Anna Rabajczyk, Tomasz Wilczyński and Daniel Małozięć
Materials 2025, 18(16), 3752; https://doi.org/10.3390/ma18163752 - 11 Aug 2025
Viewed by 393
Abstract
The development of industry and technology, despite making everyday life easier, generates large amounts of various wastes that negatively affect the environment. Unexpected leaks of substances such as oils, petroleum substances, and chemicals also contribute to the degradation of aquatic and terrestrial ecosystems. [...] Read more.
The development of industry and technology, despite making everyday life easier, generates large amounts of various wastes that negatively affect the environment. Unexpected leaks of substances such as oils, petroleum substances, and chemicals also contribute to the degradation of aquatic and terrestrial ecosystems. Long-term effects of environmental pollution require the development of advanced materials and technologies to collect and neutralize pollutants. Sorbents obtained from waste, including banana peels, coconut fibers, and polyurethane foams from recycling the thermal housing of refrigeration devices, allow a reduction in the amount of generated waste and the development of appropriate sorbents. This work focuses on comparing the sorption and neutralization properties of these materials for two types of oil, machine and diesel, and the possibility of using them in rescue and firefighting operations conducted by firefighters. The results obtained indicate that the viscose–cellulose sorbent and the polyurethane foam sorbent are characterized by better performance parameters than sorbents from coffee grounds or coconut fibers. The best parameters were obtained after the first 10 min of the sorbent–contaminant reaction, whereas in the case of contamination with machine oil, the absorption capacity was better than for diesel oil for each sorbent subjected to analysis. Full article
(This article belongs to the Section Green Materials)
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13 pages, 843 KB  
Article
Orange Allergy Beyond LTP: IgE Recognition of Germin-like Proteins in Citrus Fruits
by M. Soledad Zamarro Parra, Montserrat Martínez-Gomaríz, Alan Hernández, Javier Alcover, Isabel Dobski, David Rodríguez, Ricardo Palacios and Antonio Carbonell
Curr. Issues Mol. Biol. 2025, 47(8), 621; https://doi.org/10.3390/cimb47080621 - 5 Aug 2025
Viewed by 462
Abstract
Orange allergy is estimated to account for up to 3–4% of food allergies. Major allergens identified in orange (Citrus sinensis) include Cit s 1 (germin-like protein) and Cit s 2 (profilin), while Cit s 3 (non-specific lipid transfer protein, nsLTP) and [...] Read more.
Orange allergy is estimated to account for up to 3–4% of food allergies. Major allergens identified in orange (Citrus sinensis) include Cit s 1 (germin-like protein) and Cit s 2 (profilin), while Cit s 3 (non-specific lipid transfer protein, nsLTP) and Cit s 7 (gibberellin-regulated protein) have also been described. The objective of this study was to investigate the presence and IgE-binding capacity of germin-like proteins in citrus fruits other than oranges. We describe five patients with immediate allergic reactions after orange ingestion. All patients underwent skin prick tests (SPT) to aeroallergens and common food allergens, prick-by-prick testing with orange, lemon, and mandarin (pulp, peel, seeds), total IgE, specific IgE (sIgE), anaphylaxis scoring (oFASS), and the Food Allergy Quality of Life Questionnaire (FAQLQ-AF). Protein extracts from peel and pulp of orange, lemon, and mandarin were analyzed by Bradford assay, SDS-PAGE, and IgE immunoblotting using patient sera. Selected bands were identified by peptide mass fingerprinting. A 23 kDa band was recognized by all five patients in orange (pulp and peel), lemon (peel), and mandarin (peel). This band was consistent with Cit s 1, a germin-like protein already annotated in the IUIS allergen database for orange but not for lemon or mandarin. Peptide fingerprinting confirmed the germin-like identity of the 23 kDa bands in all three citrus species. Germin-like proteins of approximately 23 kDa were identified as IgE-binding components in peel extracts of orange, lemon, and mandarin, and in orange pulp. These findings suggest a potential shared allergen across citrus species that may contribute to allergic reactions independent of LTP sensitization. Full article
(This article belongs to the Section Molecular Plant Sciences)
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20 pages, 3925 KB  
Article
Anchor Biochar from Potato Peels with Magnetite Nanoparticles for Solar Photocatalytic Treatment of Oily Wastewater Effluent
by Manasik M. Nour, Hossam A. Nabwey and Maha A. Tony
Catalysts 2025, 15(8), 731; https://doi.org/10.3390/catal15080731 - 31 Jul 2025
Viewed by 383
Abstract
The current work is established with the object of modifying the source of Fenton system and substituting iron source as a catalyst with magnetite/potato peels composite material (POT400-M) to be an innovative solar photocatalyst. The structural and morphological characteristics of the material are [...] Read more.
The current work is established with the object of modifying the source of Fenton system and substituting iron source as a catalyst with magnetite/potato peels composite material (POT400-M) to be an innovative solar photocatalyst. The structural and morphological characteristics of the material are assessed through X-ray diffraction (XRD) and scanning electron microscopy (SEM). The technique is applied to treat oil spills that pollute seawater. The effectiveness of the operating parameters is studied, and numerical optimization is applied to optimize the most influential parameters on the system, including POT400-M catalyst (47 mg/L) and hydrogen peroxide reagent (372 mg/L) at pH 5.0, to maximize oil removal, reaching 93%. Also, the aqueous solution and wastewater temperature on the oxidation reaction is evaluated and the reaction exhibited an exothermic nature. Kinetic modeling is evaluated, and the reaction is found to follow the second-order kinetic model. Thermodynamic examination of the data exhibits negative enthalpy (ΔH′) values, confirming that the reaction is exothermic, and the system is verified to be able to perform at the minimal activation energy barrier (−51.34 kJ/mol). Full article
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16 pages, 3034 KB  
Article
Identification of Avocado Fruit Disease Caused by Diaporthe phaseolorum and Colletotrichum fructicola in China
by Aosiqi Ma, Yuhang Xu, Hongxing Feng, Yanyuan Du, Huan Liu, Song Yang, Jie Chen and Xin Hao
J. Fungi 2025, 11(8), 547; https://doi.org/10.3390/jof11080547 - 23 Jul 2025
Viewed by 680
Abstract
Persea americana (avocado) is a healthy fruit, rich in unsaturated fatty acids, various minerals, and vitamins. As avocado cultivation continues to expand globally, its development is increasingly constrained by concomitant diseases, among which fruit rot and anthracnose have emerged as significant threats to [...] Read more.
Persea americana (avocado) is a healthy fruit, rich in unsaturated fatty acids, various minerals, and vitamins. As avocado cultivation continues to expand globally, its development is increasingly constrained by concomitant diseases, among which fruit rot and anthracnose have emerged as significant threats to fruit quality. Menglian in Yunnan Province is the largest avocado production area in China. In November 2024, fruit rot was observed on avocado fruits in Yunnan, China, characterized by reddish-brown discoloration, premature ripening, softening, and pericarp decay, with a field infection rate of 22%. Concurrently, anthracnose was detected in avocado fruits, presenting as small dark brown spots that developed into irregular rust-colored lesions, followed by dry rot depressions, ultimately leading to soft rot, peeling, or hardened dry rot, with a field infection rate of 15%. Infected fruit samples were collected, and fungal strains were isolated, purified, and inoculated via spore suspension, followed by re-isolation. The strains were conclusively identified as Diaporthe phaseolorum (SWFU20, SWFU21) and Colletotrichum fructicola (SWFU12, SWFU13) through an integrated approach combining DNA extraction, polymerase chain reaction (PCR), sequencing, phylogenetic reconstruction, and morphological characterization. This is the first report of D. phaseolorum causing fruit rot and C. fructicola causing anthracnose on avocado in China. In future research, we will test methods for the control of D. phaseolorum and C. fructicola. The identification of these pathogens provides a foundation for future disease management research, supporting the sustainable development of the avocado industry. Full article
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13 pages, 3330 KB  
Article
Super Hydrophobic UHMWPE/PTFE/PVA Composites with Low Friction: Preparation and Wear Mechanism
by Hai Wang, Zhiwei Shao, Kuiyuan Shen, Buhe Bateer, Fushen Ren and Xiaowen Qi
Polymers 2025, 17(12), 1664; https://doi.org/10.3390/polym17121664 - 16 Jun 2025
Viewed by 518
Abstract
This study develops novel superhydrophobic UHMWPE/PTFE/PVA composites via hot-pressing sintering to achieve ultra-low friction and enhanced wear resistance. The ternary system synergistically combines UHMWPE’s mechanical stability, PTFE’s lubricity, and PVA’s dispersion/binding capability. Results show PTFE disrupts UHMWPE crystallization, reducing melting temperature by 2.77 [...] Read more.
This study develops novel superhydrophobic UHMWPE/PTFE/PVA composites via hot-pressing sintering to achieve ultra-low friction and enhanced wear resistance. The ternary system synergistically combines UHMWPE’s mechanical stability, PTFE’s lubricity, and PVA’s dispersion/binding capability. Results show PTFE disrupts UHMWPE crystallization, reducing melting temperature by 2.77 °C and enabling energy dissipation. All composites exhibit hydrophobicity, with optimal formulations (UPP3/UPP4) reaching superhydrophobicity. Tribological testing under varied loads and frequencies reveals low friction, where UPP1 achieves a COF of 0.043 and wear rate below 1.5 × 10−5 mm3/(N·m) under low-load conditions. UHMWPE oxidative degradation forming carboxylic acids at the interface (C=O at 289 eV, C–O at 286 eV). Formation of tungsten oxides (WO3/WO2), carbides (WC), and transfer films on steel counterparts. A four-step tribochemical reaction pathway is established. PVA promotes uniform transfer films, while PTFE lamellar peeling and UHMWPE chain stability enable sustained lubrication. Carbon-rich stratified accumulations under high-load/speed increase COF via abrasive effects. The composites demonstrate exceptional biocompatibility and provide a scalable solution for biomedical and industrial tribological applications. Full article
(This article belongs to the Section Polymer Composites and Nanocomposites)
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11 pages, 2001 KB  
Communication
The Engineered Synthesis and Enhancement of Nitrogen and Chlorine Co-Doped Fluorescent Carbon Dots for the Sensitive Detection of Quercetin
by Yuan Jiao, Xuewen Miao, Lizhang Wang, Shasha Hong, Yifang Gao and Xin Wang
Materials 2025, 18(11), 2669; https://doi.org/10.3390/ma18112669 - 5 Jun 2025
Viewed by 455
Abstract
Flavonoid alcohols, particularly quercetin, as emerging antioxidants, demand advanced detection methodologies to comprehensively explore and evaluate their potential environmental and health risks. In this study, nitrogen–chlorine co-doped carbon dots (N, Cl-CDs), featuring an extended wavelength emission at 625 nm, were synthesized via the [...] Read more.
Flavonoid alcohols, particularly quercetin, as emerging antioxidants, demand advanced detection methodologies to comprehensively explore and evaluate their potential environmental and health risks. In this study, nitrogen–chlorine co-doped carbon dots (N, Cl-CDs), featuring an extended wavelength emission at 625 nm, were synthesized via the reaction of 4-chloro-1,2-phenylenediamine with polyethyleneimine. The engineered N, Cl-CDs exhibit superior photostability, exceptional aqueous dispersibility, and anti-interference capability in complex matrices. Leveraging static electron transfer mechanisms, the N, Cl-CDs demonstrate selective fluorescence quenching toward quercetin with an ultralow detection limit of 60.42 nM. Validation through rigorous spiked recovery assays in apple peel and red wine has been proficiently performed with satisfactory accuracy, highlighting the significant prospect of the constructed N, Cl-CDs for quercetin identification in real samples. This study provides valuable insights into the analytical determination of flavonoid compounds in complex environmental matrices, highlighting the potential of N, Cl-CDs for environmental and food safety monitoring. Full article
(This article belongs to the Section Smart Materials)
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15 pages, 3353 KB  
Article
N-S Co-Doped WC Nanoparticles Show High Catalytic Activity in Hydrogen Evolution Reaction
by Zhaobin Lu, Baoxin Wang, Shengtao Li, Feiyan Pan, Xuewei Zhu and Xiaofeng Wei
Coatings 2025, 15(6), 630; https://doi.org/10.3390/coatings15060630 - 24 May 2025
Viewed by 392
Abstract
In the “dual carbon” objective, the preparation of non-precious metal catalysts with low cost and high activity is essential for the study of hydrogen evolution reactions (HERs). This study employed biomass pomelo peel powder as the carbon source and ammonium metatungstate (AMT) as [...] Read more.
In the “dual carbon” objective, the preparation of non-precious metal catalysts with low cost and high activity is essential for the study of hydrogen evolution reactions (HERs). This study employed biomass pomelo peel powder as the carbon source and ammonium metatungstate (AMT) as the tungsten source and, through a facile one-step method in molten salt, fabricated a biomass carbon-based nanocatalyst featuring carbon flakes adorned with tungsten carbide (WC) nanoparticles. Dicyandiamide and cysteine were introduced as nitrogen and sulfur sources, respectively, to explore the impacts of N-S elemental doping on the structure, composition, and HER performance of the WC/C catalyst. The experimental results showed that N-S doping changed the electronic structure of WC and increased the electrochemically active surface area, resulting in a significant increase in the HER activity of WC/C@N-S catalysts. The WC/C@N-S catalyst was evaluated with hydrogen evolution performance in a 0.5 mol/L H2SO4 solution. When the cathodic current density reached 10 mA/cm2, the overpotential was 158 mV, and the Tafel slope was 68 mV/dec, underscoring its excellent HER performance. The outcomes offer novel insights into the high-value utilization of agricultural biomass resources, and pave the way for the development of cost-effective, innovative hydrogen evolution catalysts. Full article
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20 pages, 5514 KB  
Article
The Tailored Surface Oxygen Vacancies and Reduced Optical Band Gap of NiO During the Development of NiO@Polyaniline Hybrid Materials for the Efficient Asymmetric and Oxygen Evolution Reaction Applications
by Fida Hussain, Wanhinyal Dars, Rabia Kanwal, Jethanand Parmar, Ghansham Das, Ahmed Raza, Haresh Kumar, Rameez Mangi, Masroor Ali Bhellar, Ambedker Meghwar, Kashif Ali, Aneela Tahira, Muhammad Ali Bhatti, Elmuez Dawi, Rafat M. Ibrahim, Brigitte Vigolo and Zafar Hussain Ibupoto
Catalysts 2025, 15(6), 508; https://doi.org/10.3390/catal15060508 - 22 May 2025
Viewed by 3902
Abstract
This study employed a simple and cost-effective method for developing NiO with reduced optical band gaps that can be combined with nanostructured polyaniline (PANI). The composite systems were used as electrocatalytic and electrode materials in oxygen evolution reactions (OER) and in supercapacitor applications. [...] Read more.
This study employed a simple and cost-effective method for developing NiO with reduced optical band gaps that can be combined with nanostructured polyaniline (PANI). The composite systems were used as electrocatalytic and electrode materials in oxygen evolution reactions (OER) and in supercapacitor applications. We prepared the composite material in two stages: NiO was prepared with a reduced optical band gap by combining it with wheat peel extract. This was followed by the incorporation of PANI nanoparticles during the chemical oxidation polymerization process. A variety of structural characterization techniques were employed, including scanning electron microscopy (SEM), powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). A surface-modified NiO/PANI composite with enhanced surface area, fast charge transfer rate, and redox properties was produced. When NiO/PANI composites were tested in KOH electrolytic solution, 0.5 mL of wheat peel extract-mediated NiO/PANI demonstrated excellent electrochemical performance. It was found that the asymmetric supercapacitor (ASC) device had the highest specific capacitance of 404 Fg−1 at a current density of 4 Ag−1. In terms of energy density and power density, the ASC device was found to have 140 Whkg−1 and 3160 Wkg−1, respectively. The ASC device demonstrated excellent cycling stability and charge storage rates, with 97.9% capacitance retention and 86.9% columbic efficiency. For the OER process, an overpotential of 320 mV was observed at a current density of 10 mA/cm2. It was found that the NiO/PANI composite was highly durable for a period of 30 h. A proposed hypothesis suggested that reducing the optical band gap of NiO and making its composites with PANI could be an appealing approach to developing next-generation electrode materials for supercapacitors, batteries, and fuel cells. Full article
(This article belongs to the Special Issue Advances in Biomass-Based Electrocatalysts)
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16 pages, 4695 KB  
Article
Hematite Nanoparticles Synthesized by Green Route: Characterization, Anticancer and Antioxidant Activities
by Safa Ezzine, Hela Ferjani, Oluwasayo E. Ogunjinmi and Damian C. Onwudiwe
Inorganics 2025, 13(5), 167; https://doi.org/10.3390/inorganics13050167 - 15 May 2025
Viewed by 936
Abstract
Recently, attention has shifted towards the green synthesis of nanoparticles using plant extracts rich in phytochemicals like phenols and flavonoids, offering an alternative method that avoids harmful chemicals and enables large-scale, low-cost production. This study introduces a straightforward and eco-friendly approach to synthesizing [...] Read more.
Recently, attention has shifted towards the green synthesis of nanoparticles using plant extracts rich in phytochemicals like phenols and flavonoids, offering an alternative method that avoids harmful chemicals and enables large-scale, low-cost production. This study introduces a straightforward and eco-friendly approach to synthesizing hematite α-Fe2O3 nanoparticles utilizing an aqueous extract of Musa paradisiaca. The variation in the calcination temperature resulted in the formation of nanoparticles presented as Fe2O3 (1), Fe2O3 (2), and Fe2O3 (3), obtained at 650, 750, and 900 °C for 4 h, respectively. This variation allowed for an investigation into the impact of different reaction temperatures on the structural and optical properties of the nanoparticles. Structural analysis was conducted using X-ray diffraction (XRD), while scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to examine morphology. Optical properties were assessed via UV-vis spectroscopy, revealing a reduction in the energy band gap (from 2.5 to 1.87 eV), attributed to an increase in crystallite size resulting from longer calcination temperatures (650–900 °C). A biological assay was carried out to evaluate the antioxidant and anticancer potentials of the nanoparticles. Both Fe2O3 (1) and Fe2O3 (2) with IC50 values of 46.84 and 46.14 µg/mL, respectively, showed similar antioxidant potentials, while peel extract exhibited the least activity with an IC50 of 79.26 µg/mL. The nanoparticles, peels, and 5-FU (used as standard) showed a stronger inhibitory effect on the Human Embryonic Kidney (HEK) 293 cells compared to the HeLa cells. This implies that the HEK 293 cells might be more susceptible to the drug samples and a lower concentration might even be sufficient to achieve the inhibition of normal cell proliferation. These results indicate a better therapeutic window with a lesser inhibitory effect compared to standard drugs used as controls. Full article
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17 pages, 5118 KB  
Article
Nickel-Modified Orange Peel Biochar for the Efficient Adsorptive Removal of Eriochrome Black T from Aqueous Solution
by Ayesha Kanwal, Jawaria Abid, Waqar-Un-Nisa, Seema Gul, Muhammad Nouman, Abubakr M Idris and Habib Ullah
Water 2025, 17(10), 1484; https://doi.org/10.3390/w17101484 - 14 May 2025
Cited by 1 | Viewed by 940
Abstract
The widespread discharge of synthetic dyes such as Eriochrome Black T (EBT) into water bodies poses significant environmental and health concerns due to their toxicity, persistence, and resistance to degradation. In response to this issue, the removal of EBT dye from aqueous solutions [...] Read more.
The widespread discharge of synthetic dyes such as Eriochrome Black T (EBT) into water bodies poses significant environmental and health concerns due to their toxicity, persistence, and resistance to degradation. In response to this issue, the removal of EBT dye from aqueous solutions using nickel-modified orange peel biochar (MOPB) was investigated in this study at various experimental conditions such as adsorbent dose, pH, concentration of dye, temperature, and contact time. Biochar was prepared from orange peels via pyrolysis, and structural characterization was performed using FTIR, XRD, and SEM to assess morphological changes, pore structure, and functional groups post-modification. MOPB exhibited significantly enhanced adsorption capacity compared to unmodified biochar. Optimal removal (at 0.1 g adsorbent dose, 25 ppm dye concentration, 90 min contact time, 35 °C, and pH 4) resulted in maximum EBT elimination. The equilibrium dataset was evaluated using Langmuir and Freundlich isotherm models. The Langmuir model (R2 = 0.99) best described the uptake of EBT dye, which implies that the adsorption of EBT dye onto MOPB was monolayered. The kinetic data were also analyzed using pseudo-first-order and pseudo-second-order models. The pseudo-second-order kinetic model was found to be the best fit (R2 = 0.99), indicating that it governs the rate-limiting step of the reaction. Thermodynamic parameters confirmed that the adsorption process is spontaneous and exothermic. These findings demonstrate the potential of MOPB as a low-cost, sustainable adsorbent for the efficient removal of EBT from industrial wastewater. Full article
(This article belongs to the Special Issue Science and Technology for Water Purification, 2nd Edition)
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15 pages, 7197 KB  
Article
Chemical Recycling of Catalytic Glycolysis of Polyethylene Terephthalate with Potassium-Rich Biomass
by Zhe Bai, Zhixian Bao and Haoquan Hu
Recycling 2025, 10(3), 85; https://doi.org/10.3390/recycling10030085 - 2 May 2025
Viewed by 1971
Abstract
Polyethylene terephthalate (PET) products are ubiquitous in daily life, offering convenience but posing significant environmental challenges due to their persistence and the difficulty of recycling them. Improper disposal of waste PET contributes to severe pollution and resource loss. Chemical degradation has emerged as [...] Read more.
Polyethylene terephthalate (PET) products are ubiquitous in daily life, offering convenience but posing significant environmental challenges due to their persistence and the difficulty of recycling them. Improper disposal of waste PET contributes to severe pollution and resource loss. Chemical degradation has emerged as one of the most effective methods for recovering and reusing waste PET. This article introduces a catalytic glycolysis strategy for efficient and environmentally sustainable PET recycling using potassium-rich biomass, specifically banana peels. The study demonstrated that K2O and K2CO3, derived from calcined banana peels, significantly catalyze the glycolysis of PET. Under optimal conditions, complete degradation of PET was achieved within 1.5 h at 180 °C, without additional chemical reagents. Product distribution confirmed that high-purity bis(2-hydroxyethyl) terephthalate could be obtained. The interaction between K2CO3 and ethylene glycol plays a critical role in determining the competition between glycolysis and alkaline hydrolysis. Furthermore, Density Functional Theory calculations provided valuable insights into the transesterification process during glycolysis. The reaction system also demonstrated excellent compatibility with colored PET products. This study successfully realized the simultaneous recycling of post-consumer PET and banana peels, offering a novel and sustainable approach to waste valorization. Full article
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20 pages, 3041 KB  
Article
Active Polylactic Acid (PLA) Films Incorporating Almond Peel Extracts for Food Preservation
by Laia Martin-Perez, Carolina Contreras, Amparo Chiralt and Chelo Gonzalez-Martinez
Molecules 2025, 30(9), 1988; https://doi.org/10.3390/molecules30091988 - 29 Apr 2025
Cited by 1 | Viewed by 651
Abstract
Almond peel extracts, containing 0.2–0.8% (w/w) phenolic compounds with notable antioxidant and antimicrobial activities, could be used as a natural source of active compounds for the development of active films for food preservation. In this study, almond peel extracts [...] Read more.
Almond peel extracts, containing 0.2–0.8% (w/w) phenolic compounds with notable antioxidant and antimicrobial activities, could be used as a natural source of active compounds for the development of active films for food preservation. In this study, almond peel extracts obtained by subcritical water extraction at 160 and 180 °C were incorporated into PLA films (PLA-E160 and PLA-E180). The films were characterized in terms of their microstructure, mechanical, barrier, optical and thermal properties. Furthermore, the release of phenolic compounds and hydroximethylfurfural (HFM) into food simulants with different polarity was evaluated, as well as the film’s potential antioxidant and antimicrobial activities. To validate their effectiveness as active packaging materials, shelf-life studies were conducted on fresh orange juice and sunflower oil packaged using PLA-160 films. The results show that the incorporation of the almond peel extracts led to significant changes in the films’ microstructure and mechanical properties, which became darker, mechanically less resistant, and stretchable (p < 0.05), with slightly lower thermal stability than neat PLA films. The release of phenolic compounds and HFM from extract-enriched films was promoted in the 95% ethanol simulant due to the matrix swelling and relaxation. Food products packaged with PLA-E160 exhibited slower oxidative degradation during storage, as indicated by the higher ascorbic acid content and hue color in orange juice and lower peroxide content in sunflower oil. Nevertheless, both in vivo and in vitro studies showed no antimicrobial effectiveness from the films, likely due to the limited release of active compounds to the surrounding medium. Thus, almond peel extract conferred valuable properties to PLA films, effectively reducing oxidative reactions in food products sensitive to these deterioration processes. Full article
(This article belongs to the Special Issue Bio-Based Polymers for Sustainable Future)
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21 pages, 3564 KB  
Article
Avocado Seed Waste as a Green Catalyst for the Sustainable Oxidation of Limonene with Molecular Oxygen
by Sylwia Gajewska, Joanna Siemak, Agnieszka Wróblewska and Beata Michalkiewicz
Sustainability 2025, 17(9), 3923; https://doi.org/10.3390/su17093923 - 27 Apr 2025
Viewed by 946
Abstract
Avocado is a rich source of numerous nutrients, such as micro- and macroelements, essential unsaturated fatty acids, and vitamins essential for the correct functioning of the body. Consequently, its consumption has significantly increased in recent years. The primary edible part of the fruit [...] Read more.
Avocado is a rich source of numerous nutrients, such as micro- and macroelements, essential unsaturated fatty acids, and vitamins essential for the correct functioning of the body. Consequently, its consumption has significantly increased in recent years. The primary edible part of the fruit is the flesh, while the seed is still considered biowaste. Currently, various methods for utilization of this biowaste are being explored, prompting the authors of this work to investigate the catalytic properties of ground avocado seeds. Dried, ground avocado seeds were used as the catalyst in the environmentally friendly oxidation of limonene with oxygen. The process was carried out in mild conditions, without the use of any solvent and at atmospheric pressure. The studies examined the influence of temperature (70–110 °C), the amount of the catalyst (0.5–5.0 wt%), and the reaction time (15–360 min). The analyses of the post-reaction mixtures were performed using the gas chromatography method (GC). The maximum value of the conversion of limonene obtained during the tests was 36 mol%. The main products of this process were as follows: 1,2-epoxylimonene, carveol, and perillyl alcohol. Also, the following compounds were determined in the post-reaction mixtures: carvone and 1,2-epoxylimonene diol. The studied process is interesting, taking into account both the management of waste in the form of avocado seeds and possible wide applications of limonene transformation products in medicine, cosmetics and the food industry. Given that limonene is now increasingly being extracted from waste orange peels, this is also a good way to manage the future naturally derived limonene and reduce the amount of waste orange peels. The presented studies fit perfectly with the goals of sustainable development and circular economy and may be the basis for the future development of “green technology” for obtaining value-added oxygenated derivatives of limonene. These studies show the use of waste biomass in the form of avocado seeds to obtain a green catalyst. In this context, our research presents an effective way of waste valorization. Full article
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