Search Results (160)

High ash content in algal biomass limits its suitability for biofuel production by reducing combustion efficiency and increasing fouling. This study presents a green deashing strategy using nitrilotriacetic acid (NTA) and deionized (DI) water to purify Scenedesmus algae, which was selected for its high ash removal potential. The optimized sequential treatment (DI, NTA chelation, and DI+NTA treatment at 90–130 °C) achieved up to 83.07% ash removal, reducing ash content from 15.2% to 3.8%. Elevated temperatures enhanced the removal of calcium, magnesium, and potassium, while heavy metals like lead and copper were reduced below detection limits. CHN analysis confirmed minimal loss of organic content, preserving biochemical integrity. Unlike traditional acid leaching, this method is eco-friendly after three cycles. The approach offers a scalable, sustainable solution to improve algal biomass quality for thermochemical conversion and supports circular bioeconomy goals. Full article

Poly(acrylic acid) (PAA) and hydroxypropylcellulose (HPC) hydrogels were synthesized in the absence of a crosslinker. Chemical crosslinking between PAA and HPC was demonstrated through free radical polymerization by a precipitation reaction in acetone as the solvent. These hydrogels exhibited smaller swelling ratios (1 to 5 g H₂O/g) than homo PAA hydrogels synthesized in water as the solvent. They were swollen in a 0.1 M NaOH solution and subsequently used to remove Ni²⁺ ions from aqueous solutions with concentrations ranging from 1000 to 4000 ppm. The absorption capacity of these hydrogels ranged from 91 to 340 mg of Ni²⁺/g in a rapid 1 h process, and from 122 to 435 mg of Ni²⁺/g in a 24 h process, demonstrating an improvement in Ni²⁺ absorption compared to previously reported hydrogels. The colored 1000 and 2000 ppm Ni²⁺ solutions became clear after treatment, while the PAA-HPC hydrogels turned green due to the uptake of Ni²⁺ ions, which were partially chelated by carboxylate groups as nickel polyacrylate and partially precipitated as Ni(OH)₂, resulting in an average absorption efficiency of 80%. The hydrogel was able to release the absorbed Ni²⁺ upon immersion in an HCl solution, with an average release percentage of 76.4%, indicating its potential for reuse. These findings support the use of PAA-HPC hydrogels for cleaning Ni²⁺-polluted water. The cost of producing 1 g of these hydrogels in laboratory conditions is approximately 0.2 USD. Full article

Surimi products are popular due to their high protein and low fat content. However, traditional processing methods rely on high concentrations of salt (2–3%) to maintain texture and stability, contributing to excessive sodium intake. As global health trends advance, developing green and low-salt technologies while maintaining product quality has become a research focus. Alkaline amino acids regulate protein conformation and intermolecular interactions through charge shielding, hydrogen bond topology, metal chelation, and hydration to compensate for the defects of solubility, gelation, and emulsification stability in the low-salt system. This article systematically reviews the mechanisms and applications of alkaline amino acids in reducing salt and maintaining quality in surimi. Research indicates that alkaline amino acids regulate the conformational changes of myofibrillar proteins through electrostatic shielding, hydrogen bond topology construction, and metal chelation, significantly improving gel strength, water retention, and emulsion stability in low-salt systems, with the results comparable to those in high-salt systems. Future research should optimize addition strategies using computational simulations technologies and establish a quality and safety evaluation system to promote industrial application. This review provides a theoretical basis for the green processing and functional enhancement of surimi products, which could have significant academic and industrial value. Full article

Secondary iron overload exacerbates osteoporosis by elevating reactive oxygen species (ROS), which suppress osteoblast function and enhance osteoclast activity, disrupting bone remodeling. Reducing iron overload and oxidative stress may improve bone health. Epigallocatechin-3-gallate (EGCG), the main bioactive compound in green tea extract (GTE), is recognized for its antioxidant and iron-chelating properties. This study examined the effect of GTE on bone formation and mineralization in iron-overloaded human osteoblast-like MG-63 cells. An iron-overloaded model was established using ferric ammonium citrate (FAC), followed by treatment with GTE, deferiprone (DFP), or their combination. GTE significantly reduced intracellular iron, ROS levels, and lipid peroxidation while upregulating the osteogenic marker BGLAP, the anti-resorptive marker OPG, and osteogenic mineralization, indicating restored bone health. These results suggest that EGCG-containing GTE mitigates iron-induced oxidative stress and promotes osteogenesis, highlighting its potential as a natural therapeutic supplement for managing iron-overload-associated osteoporosis. Full article

Green-synthesized metal nanoparticles show promise in nanomedicine and material engineering. In this study, the polysaccharide of Zingiber officinale (ZOP) was used as a raw material. Through single-factor experiments and a response surface methodology, the optimum synthesis protocol of Zingiber officinale polysaccharide silver nanoparticles (ZOP-NPs-AgNPs) was determined as follows: V(AgNO₃):V(ZOP) = 2.98:1, 59.79 °C, 3 h, pH 9, and 20 mL NaCl, achieving a 92.51% silver chelation rate. Structure analysis revealed that ZOP-NPs-AgNPs were spherical or quasi-spherical, with a particle size < 20 nm and a face-centered cubic crystal structure, which has good thermal stability. Subsequent studies explored the antibacterial and immunomodulatory effects of ZOP-NPs-AgNPs. The minimum inhibitory concentration (MIC) of ZOP-NPs-AgNPs against Escherichia coli and Staphylococcus aureus was determined to be 0.5000 mg/mL and 0.0310 mg/mL, respectively, while the minimum bactericidal concentration (MBC) was 0.5000 mg/mL and 0.0310 mg/mL, respectively. Additionally, ZOP-NPs-AgNPs significantly enhance RAW264.7 cell proliferation and phagocytosis and boost IL−1β, IL−6, NO, and TNF-α production. This confirms that ZOP can act as a green reductant and stabilizer, offering a new method for green nano-silver synthesis. This provides a sustainable way to produce antibacterial products and functional foods, and offers useful references for eco-friendly nano-silver applications. Full article

This study synthesized two eco-friendly inhibitors—a chitosan–copper metal–organic framework (CS@Cu MOF) and chitosan–Schiff base–Cu complex (Schiff–CS@Cu)—for Q345 steel protection in 3.5% NaCl/1M HCl. Electrochemical and weight loss analyses demonstrated exceptional corrosion inhibition: untreated specimens showed a 25.889 g/(m²·h) corrosion rate, while 100 mg/L of CS@Cu MOF and Schiff–CS@Cu reduced rates to 2.50 g/(m²·h) (90.34% efficiency) and 1.67 g/(m²·h) (93.56%), respectively. Schiff–CS@Cu’s superiority stemmed from its pyridine–Cu²⁺ chelation forming a dense coordination barrier that impeded Cl⁻/H⁺ penetration, whereas CS@Cu MOF relied on physical adsorption and micro-galvanic interactions. Surface characterization revealed that Schiff–CS@Cu suppressed pitting nucleation through chemical coordination, contrasting with CS@Cu MOF’s porous film delaying uniform corrosion. Both inhibitors achieved optimal performance at 100 mg/L concentration. This work establishes a molecular design strategy for green inhibitors, combining metal–organic coordination chemistry with biopolymer modification, offering practical solutions for marine infrastructure and acid-processing equipment protection. Full article

Biosurfactants have emerged as promising agents for environmental remediation due to their ability to complex, chelate, and remove heavy metals from contaminated environments. This review evaluates their potential for recovering critical minerals from waste materials to support renewable energy production, emphasizing the role of biosurfactant–metal interactions in advancing green recovery technologies and enhancing resource circularity. Among biosurfactants, rhamnolipids demonstrate a high affinity for metals such as lead, cadmium, and copper due to their strong stability constants and functional groups like carboxylates, with recovery efficiencies exceeding 75% under optimized conditions. Analytical techniques, including Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Fourier-Transform Infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM), are instrumental in assessing recovery efficiency and interaction mechanisms. The review introduces a Green Chemistry Metrics Framework for evaluating biosurfactant-based recovery processes, revealing 70–85% lower Environmental Factors compared to conventional methods. Significant research gaps exist in applying biosurfactants for extraction of metals like lithium and cobalt from batteries and other waste materials. Advancing biosurfactant-based technologies hold promise for efficient, sustainable metal recovery and resource circularity, addressing both resource scarcity and environmental protection challenges simultaneously. Full article

Background/Objectives: This study reports the green synthesis, optimization, characterization, and multifunctional evaluation of silver nanoparticles (AgNPs) using an ethanolic Aronia melanocarpa berry extract. The objective was to establish optimal synthesis conditions; assess the in vitro stability; and evaluate the antioxidant, photocatalytic, and photoprotective activities. Methods: The cytogenotoxic effects of the AgNPs were evaluated on Triticum aestivum roots. The AgNPs were synthesized via bioreduction using an ethanolic extract of A. melanocarpa under varied pH, AgNO₃ concentration, extract/AgNO₃ ratio, temperature, and stirring time, with optimization guided by UV–Vis spectral analysis. The AgNPs were further characterized by FTIR, DLS, TEM, and EDX. In vitro stability was evaluated over six months in different dispersion media (ultrapure water; 5% NaCl; and PBS at pH 6, 7, and 8). Biological assessments included antioxidant assays (lipoxygenase inhibition, DPPH radical scavenging, metal chelation, and hydroxyl radical scavenging), photocatalytic dye degradation, and SPF determination. Results: Optimal synthesis was achieved at pH 8, 3 mM AgNO₃, extract/AgNO₃ ratio of 1:9, 40 °C, and 240 min stirring. The AgNPs were spherical (TEM), well dispersed (PDI = 0.32), and highly stable (zeta potential = −40.71 mV). PBS pH 6 and 7 ensured the best long-term colloidal stability. The AgNPs displayed strong dose-dependent antioxidant activity, with superior lipoxygenase inhibition (EC₅₀ = 18.29 µg/mL) and the effective photocatalytic degradation of dyes under sunlight. Photoprotective properties were confirmed through UV absorption analysis. The AgNPs showed a strong antimitotic effect on wheat root cells. Conclusions: The study demonstrates that A. melanocarpa-mediated AgNPs are stable, biologically active, and suitable for potential biomedical, cosmetic, and environmental applications, reinforcing the relevance of plant-based nanotechnology. Full article

With increasing energy demands, fuel cells are a popular avenue for portability and low waste emissions. Hydrogen fuel cells are popular due to their potential output power and clean waste. However, due to storage and transport concerns, hydrogen peroxide fuel cells are a promising alternative. Although they have a lower output potential compared to hydrogen fuel cells, peroxide can act as both the oxidizing and reducing agent, simplifying the structure of the cell. In addition to reducing the complexity, hydrogen peroxide is stable in liquid form and can be stored in less demanding methods. This paper investigates chelated metals as electrode material for hydrogen peroxide fuel cells. Chelated metal complexes are ring-like structures that form from binding organic or inorganic compounds with metal ions. They are used in medical imaging, water treatment, and as catalysts for reactions. Copper(II) phthalocyanine, phthalocyanine green, poly(copper phthalocyanine), bis(ethylenediamine)copper(II) hydroxide, iron(III) ferrocyanine, graphene oxide decorated with Fe₃O₄, zinc phthalocyanine, magnesium phthalocyanine, manganese(II) phthalocyanine, cobalt(II) phthalocyanine are investigated as electrode materials for peroxide fuel cells. In this study, the performance of these materials is evaluated using cyclic voltammetry. The voltammograms are compared, as well as observations are made during the materials’ use to measure their effectiveness as electrode material. There has been limited research comparing the use of these chelated metals in the context of hydrogen peroxide fuel cells. Through this research, the goal is to further the viability of hydrogen peroxide fuel cells. Poly(copper phthalocyanine) and graphene oxide doped with iron oxides had strong redox catalytic activity for use in acidic peroxide single-compartment fuel cells, where the poly(copper phthalocyanine) electrode compound generated the highest peak power density of 7.92 mW/cm² and cell output potential of 0.634 V. Full article

Many of today’s innovative materials used to carry trace elements (TEs) are derived from chelates. Most of the materials used for this purpose have been produced on the basis of EDTA, which is not considered to be environmentally friendly due to its high persistence. Research is therefore being carried out to produce materials that do not pose an environmental risk. Therefore, a study was carried out to determine the effects of newly developed innovative materials with embedded biodegradable and environmentally safe chelates (IDHA—iminodisuccinic acid—and N-butyl-D-gluconamide ligands) containing copper, molybdenum and iron on the yield, biometric characteristics and chemical composition of soybean and selected soil properties. It is difficult to find publications on their effects in soybean cultivation. The greatest increase in soybean leaf greenness index (SPAD) was found after the addition of pure Salmag^® (Sal.^®). The effect of the chelates on the SPAD index was lower, with Sal.^® + Fe chelate having the greatest effect during the vegetative development stage and Cu chelate having the greatest effect during the flowering stage. Sal.^® + Cu, especially with Fe, accelerated pod and seed ripening in the last vegetative stage of soybean. Sal.^® + Cu had the most favourable impact on plant height, pure Sal.^® on the pod number per plant, Sal.^® + Fe on the seed number per pod, Sal.^® with Mo and Fe chelates on soybean seed yield, and pure Sal.^® on fresh weight remaining above-ground part yield, while pure Sal.^® and Sal.^® + Fe had the most favourable impact on dry weight aerial yield. The fertiliser materials (especially Sal.^® + Cu) generally increased the N content of the tested soybean organs and the Cu content of the other above-ground soybean parts (especially those containing chelates) and had an antagonistic effect on the Mg content of the soybean above-ground parts. Sal.^® + Cu also had a negative effect on the Fe content of other above-ground soybean parts. Sal.^® + Fe had a positive impact on the iron content, and Sal.^® + Mo had a positive impact on the molybdenum content of soybean. The applied fertilisers had little effect on the contents of Cu, Mo and Fe in the soil. There was only a significant increase in the Cu content of the soil after the addition of Sal.^® + Cu and a significantly smaller increase under the influence of Sal.^® without chelates, as well as an increase in the Mo content of the soil with Sal.^®. The present study confirms the beneficial impact of the novel materials with chelates. It has been demonstrated that the presence of materials containing Mo and, in particular, Cu has a considerable effect on the yield and quality characteristics of soybeans. Full article

Lead is a harmful heavy metal known to alter the environment and affect human health. Several industries have contributed to the increase in lead contamination, making it a major global concern. Thus, remediation strategies are necessary to prevent lead bioaccumulation and deleterious health effects. The aim of this study was to determine the capacity of the green microalga Chlorella vulgaris (C. vulgaris or CV) to remove lead in an animal model and prevent the accumulation of this heavy metal in the principal organs (brain, liver, and kidney) and blood. Forty male Wistar rats were randomly assigned to four groups (n = 10): control group (CT); C. vulgaris supplementation group, 5% of the diet (CV); lead acetate administration group, 500 ppm (Pb); and C. vulgaris supplementation group, 5% of the diet plus lead acetate administration group, 500 ppm (CV–Pb). After 4 weeks of exposure, we measured lead accumulation, memory function, oxidative stress, and antioxidant activity (SOD and GSH). Lead exposure altered memory function, increased oxidative stress in the brain and kidney, and increased SOD activity in the brain. Supplementation with C. vulgaris restored memory function to control levels; reduced oxidative stress in the brain and kidney; and decreased the accumulation of lead in the liver, kidney, and blood of rats exposed to lead. Based on our results, C. vulgaris is a lead chelating and antioxidant agent in animal models. Full article

Chalcopyrite and molybdenite are vital strategic metal resources. Due to their close association in ores, flotation methods are commonly used for separation. The flotation separation method primarily employs the “copper depression and molybdenum flotation” process, enhancing the wettability difference between chalcopyrite and molybdenite through a chalcopyrite depressant. Traditional depressants often face challenges, including low selectivity, high dosage requirements, poor stability, and significant environmental pollution, highlighting the need for new, highly selective green reagents. This study introduces the novel chalcopyrite depressant 2-mercapto-6-methylpyrimidin-4-ol (MMO) for flotation separation. The influence of MMO on chalcopyrite and molybdenite flotation recovery was examined through microflotation experiments. Additionally, the effects of MMO and ethyl xanthate on surface wettability were assessed via contact angle measurements. The adsorption microstructure and interaction mechanism of MMO on chalcopyrite were elucidated using FT-IR, TOF-SIMS, and XPS analyses and DFT simulations. Results indicate that MMO enhances chalcopyrite hydrophilicity and exhibits a strong depressing effect on its flotation, while minimally impacting molybdenite recovery. Thus, it serves as an effective depressant. During adsorption, N and S atoms in MMO donate electrons to Fe and Cu ions, leading to triple bond adsorption and a stable chelate structure. These findings are crucial for achieving a greener and more efficient flotation separation of copper and molybdenum. Full article

Selenium nanoparticles (SeNPs) attract considerable attention for their promising applications in the biomedical field, driven by their unique properties and antioxidant activities. However, their practical use is often hindered by issues such as instability and aggregation. In this study, a polysaccharide, P2, extracted from Ononis natrix, was used to stabilize SeNPs to address these limitations. P2-SeNPs were prepared through a green synthesis method involving sodium selenite, P2, and ascorbic acid, and characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD). P2-SeNPs exhibited a smaller particle size and enhanced stability compared to unmodified SeNPs. UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) demonstrated the presence of Se–O bonds, suggesting effective stabilization by covalent bonding between SeNPs and P2. Stability tests revealed that P2-SeNPs maintained good dispersion under various conditions, with optimal stability observed at refrigerated temperatures and neutral pH. Moreover, P2-SeNPs exhibited better antioxidant activities than unmodified SeNPs, as evidenced by higher DPPH radical scavenging, ABTS radical scavenging, and metal chelation ratios. This difference is attributed to both the reduced aggregation and smaller size of P2-SeNPs. Therefore, it is concluded that P2-SeNPs exhibit significant potential as an effective antioxidant agent for biomedical applications. Full article

Wilson’s disease (WD) is an inherited disorder characterized by abnormal copper metabolism with complex pathological features. Currently, the mechanism of copper overload-induced hepatic injury is unclear. Green tea is a natural chelator, and its main ingredients, green tea polyphenol (GTP) and L-theanine (L-TA) are good at binding to heavy metals like iron and copper. There have been no reports on green tea extracts (GTE) for the treatment of Wilson’s disease. This study investigated the hepatoprotective effect of GTE on WD model mice. Initially, we examined the impact of green tea extract on copper metabolism, excretion, and hepatoprotective effects in WD model toxic milk mice. Then, Ultra performance liquid chromatography (UPLC-DAD) was established to analyze GTP and L-TA in green tea extract. Further screening of eight active components and copper complex active components in green tea extract was carried out by ion analyzer. Finally, we verified the pharmacodynamic effects of these active ingredients at the animal level. The results showed that GTE improves liver function and attenuates liver injury in TX mice by promoting tissue copper excretion and inhibiting oxidative stress, which provides a theoretical basis for green tea’s potential to improve the clinical symptoms of WD. Full article

Green silica synthesis from rice husk ash represents a viable solution for promoting environmental sustainability in industrial applications. Conventional silica produced in industrial processes is often crystalline and carcinogenic, posing significant health risks to humans and environmental hazards. In this study, the production of high-purity green silica was achieved through the application of acetic acid (CH₃COOH) and tartaric acid (C₄H₆O₆) as chelating agents to effectively remove impurities. Acid leaching was performed with varying temperatures (25 °C and 75 °C) and durations (1 and 2 h). The results revealed green silica achieved SiO₂ purity of 92.21%, with the complete removal of MgO, P₂O₅, TiO₂, and CaO. The amorphous phase content is notably at 61.26%. Morphological analysis and surface area characterization confirmed an average adsorption pore size of 28.87 nm and a uniform pore size distribution of green silica in the 35–50 nm range. The surface properties and pore characteristics of the synthesized green silica meet the specifications for mesoporous silica, making it suitable for industrial purposes. This method highlights a potential alternative pathway and promotes the adoption of safe and environmentally benign chemicals, contributing to both material innovation and environmental sustainability. Full article