Eco-friendly Approach Research Articles

Enhanced Resistance to Pinewood Nematode Disease in Pinus densiflora Induced by Fungal Elicitor from Penicillium chrysogenum

Pine wilt disease, caused by the pine wood nematode (Bursaphelenchus xylophilus), poses a serious threat to forests in Korea. In this study, we investigated the resistance of Pinus densiflora to B. xylophilus following treatment with a fungal elicitor derived from Penicillium chrysogenum through trunk injection and soil drenching. Soil drenching with the fungal elicitor led to increased accumulation of two key defensive compounds: pinosylvin monomethyl ether (PME) and dihydropinosylvin monomethyl ether (DPME) in the needles. In untreated control plants inoculated with B. xylophilus, 67.9% died within five months, whereas only 33.3% of plants pretreated with the elicitor succumbed. Trunk injection of the fungal elicitor also significantly enhanced PME production. The PME concentration in the needles peaked at 155.4 µg/g dry weight (DW) four weeks post-elicitor injection. To assess the impact of elicitor treatment on nematode resistance, we monitored the downward movement of B. xylophilus in plants two months post-injection of fungal elicitor. Nematodes were introduced at the upper internodal segments of branches, and their mobility to the lower segments was measured. In elicitor-treated trees, the movement and population of B. xylophilus were significantly reduced, highlighting the effectiveness of the treatment. These results demonstrate that fungal elicitor treatments, through soil drenching or trunk injection, can enhance the resistance of P. densiflora to B. xylophilus. This eco-friendly approach offers a promising strategy for managing pine wilt disease in susceptible pine species.

Synthesis of 5-Seleno-Substituted Spirocyclopenta[b]pyridine-2,5-dien-4-ones and Benzo[h]quinolines via Radical Cyclization of Arylethynylpyridines.

A practical strategy for obtaining novel 5-seleno-substituted spirocyclopenta[b]pyridines-2,5-dien-4-ones and benzo[h]quinolines via radical cyclization is reported. The synthetic protocol explores the reaction between arylethynylpyridines and diorganyl diselenides in acetonitrile as solvent and Oxone® as oxidant at 82 °C. This easy-to-handle, eco-friendly metal-free approach was carried out under an open atmosphere, affording functionalized organoselenium compounds in good to excellent yields. Control experiments and scale-up test were performed to demonstrate the efficiency of this methodology.

Preparation of tannic acid-based recyclable adhesive with high adhesion property, low curing temperature, and environmental tolerance

Tannin-based adhesives have demonstrated promise in decreasing dependence on petrochemical resources linked to formaldehyde-based resins. However, current tannin-based adhesives face challenges due to the incorporation of expensive or toxic reagents such as isocyanate, epoxy, and formaldehyde, as well as the inability to be recycled. This study presents a simple and eco-friendly approach for producing a tannic acid-based recyclable adhesive (TA-BVB) by employing tannic acid and 1,4-butanediol divinyl ether through acetal reactions. The resulting adhesive can be cured at a low temperature of 70℃ and demonstrated high bonding strength on wood and aluminum sheets, measuring 4.45 MPa and 5.44 MPa, respectively. Notably, the adhesive maintained its adhesion strength even under harsh conditions, including high temperatures (100℃), liquid nitrogen (-196℃), and exposure to various solvents. Moreover, the adhesive showcased excellent reusability, retaining over 100 % and 86 % of bonding strength after the first and second rounds of hot pressing, respectively. This adhesive can be repaired using infrared laser irradiation and displayed remarkable mold resistance. This research underscores the potential of tannic acid in developing environmentally friendly, high-performance, recyclable adhesives with versatile applications.

Enhanced photocatalytic activity of BB41 and ROM2R dyes using green synthesized NiO nanoparticles: A response surface methodology approach

BackgroundNiO NPs are recognized for their potential in catalysis, energy storage, and environmental remediation. Green synthesis using plant extracts, such as Cucumis maderaspatanus L. (CmL.) leaves, offers an eco-friendly approach. This study focuses on synthesizing and analyzing the structural, optical, and photocatalytic properties of Cm-NiO NPs. MethodologyCm-NiO NPs were synthesized using CmL. leaf extract and calcinated at 300, 500, and 700 °C. XRD confirmed a face-centered cubic structure. Band gap values were 3.36 eV at 300 °C, 2.98 eV at 500 °C, and 3.15 eV at 700 °C. TEM showed spherical particles of 17.81 nm. The point of zero charge (pHpzc) was pH 7.95. The photocatalytic activity was tested on BB41 and ROM2R dyes under varying pH (4 – 10), dye concentrations (10 – 50 ppm), catalyst amounts (0.1 – 1.0 mg/mL), and light sources. Scavenger studies identified reactive compounds. Response surface methodology (RSM) optimized the degradation process. LC-MS analyzed degradation products, and ECOSAR software estimated their toxicity. Significant FindingsCm-NiO NPs showed high photocatalytic efficiency, degrading 93.60 % of BB41 and 88.76 % of ROM2R under UV light (250 W, 365 nm). The nanoparticles demonstrated a face-centered cubic structure and a pHpzc of 7.95. RSM effectively optimized the process, and toxicity analysis suggested a potential for environmental applications.

Efficacy of Bio-Agents in Managing Root Rot of Okra Caused by Rhizoctonia solani

Okra or lady’s finger [Abelmoschus esculentus (L.) Moench] is one of the most important summer vegetables of Rajasthan as well as India. Okra is attacked by several diseases caused by fungi and important one is root rot caused by Rhizoctonia solani Kuhn, which is an important constraint to the crop and causes significant economic losses. During present study, two bio-agents were evaluated alone and in combination Trichoderma harzianum through seed (4 g/kg) and soil (4 kg/ha) applications for two consecutive years under artificial inoculation conditions in the field. Among these, seed + soil application of Trichoderma harzianum was found most effective in reducing disease incidence (48.76%) and in increasing pod yield (13.46%) followed by seed treatment with T. harzianum + soil application of Pseudomonas fluorescens (46.41% and 12.84%, respectively). Looking to the increasing demand of organically produces in the market, root rot disease can be managed effectively with these eco-friendly approaches for supplying organically produced vegetables to fulfil the ever-increasing demand among health-conscious people.

Exploring Enzyme Encapsulation Efficiency in MOFs Using Eco-Friendly Approaches.

The encapsulation of protein enzymes in metal-organic frameworks (MOFs) has been recognized as an effective enzyme immobilization approach. In this study, we demonstrated the influence of enzyme amount and the isoelectric points (pI) of different enzymes on the enzyme loading capacity in both mechanochemical (ball-milling) and water-based approaches. We found that increasing enzyme amounts enhances MOF enzyme loading without compromising activity, while the MOF shell protects encapsulated enzymes from proteinase K degradation through its size-sheltering mechanism. However, an excess of enzymes can hinder the formation of ZIF-90. Moreover, enzymes with low pI values (e. g., catalase, pI 5.4) facilitate encapsulation in MOFs, whereas enzymes with high pI values (e. g., lysozyme, pI 11.35) are more challenging to encapsulate. The simulation results revealed that increasing the enzyme amounts and pI values raises the activation energy necessary for MOF formation. This study highlights the crucial role of enzyme properties in the encapsulation process within MOFs, providing valuable insights for fabricating enzyme-MOF biocomposites for diverse applications, such as protein drug delivery.

Cationic waste hemp fibers-based membrane: Case study of anionic pollutants removal through environmentally friendly processes

In this study, waste hemp fibers were transformed into cationically modified lignocellulosic adsorbent through a three-step process. First, a delignification/defibrillation pretreatment was performed, followed by quaternization of fibers using the synthesized ionic liquid chlorocholine chloride-urea (CCC-U). Pressure-assisted cross-linking of modified fibres, using a citric acid, produced new membrane (CCC-UHM). The removal of anionic dyes (Acid Yellow 36 (AY36), Congo Red (CR), Acid Green 25 (AG25), and Acid Blue 92 (AB92)), and oxyanions (As(V) and Cr(VI)) was tested in batch and column system. The structural characteristics and chemical properties of the syntesised materials were investigated by SEM, FTIR, Raman, XPS, XRD, specific density, porosity and point of zero charges analysis. The endothermic and spontaneous equilibration of the system resulted in high capacity (qm), i.e., 302.9 mg g−1 (AY36), 456.8 mg g−1 (CR), 812.8 mg g−1 (AG25), 587.6 mg g−1 (AB92), 107.9 mg g−1 (As(V)), and 67.84 mg g−1 (Cr(VI)) at 25 °C, using the Langmuir model. The optimum pH for the adsorption process was 7. The multi-cycle adsorption/desorption process was followed by either decolorization, using laccase from M. thermophile expressed in Aspergillus oryzae (Novozym 51,003® laccase) immobilized on amino-modified fibers as biocatalyst, or photocatalytic degradation, in the presence of zinc oxide. The high decolorization efficiency (96%) observed for AG25 and AB92 underscores the considerable potential of laccase immobilized preparations as sustainable and eco-friendly approach for treating dye-contaminated wastewater. Photodegradation process provided low environmental threat of processed water, and biodegradabilty of exhausted membrane confirmed the circularity of the developed technology with implemented principles of sustainability.

Plant growth promoting Rhizobacteria for sustainable tomato production

Numerous phosphate solubilizing bacteria (PSB) are found in the rhizosphere, benefiting the host plant in different mechanisms and promoting sustainable agriculture. They improve soil fertility with minimum cost requirements using an eco-friendly approach, which is an essential attribute for small-scale farm production. Thus, isolation, characterization, and evaluation of symbiotic effectiveness are hierarchical procedures to develop bioinoculants. Using a dual (plate and liquid medium) screening technique and a greenhouse trial, four potential PSB strains (Mk-1–25, Mk-13–16, Mk-20–7, and Mk-20–20) were selected from tomato rhizosphere soil. All isolates exhibited the following traits: produced colony clear-zone, lowered liquid medium pH, gram-positive, produced urease and IAA, dissolved substantial P from various substrates, symbiotically effective, and improved tomato growth and yield. Taxonomically, they belong to Bacillus and Priestia species (i.e., Mk-1–25 Bacillus halotolerance, Mk-13–16 Bacillus amyloliquefaciens, Mk-20–7 Bacillus megaterium, and Mk-20–20 Priestia megaterium). Among the current strains, Bacillus halotolerance recorded higher SI (3.11), was able to grow in extreme conditions (10% salt, up to 45 °C), produced HCN and siderophore, and improved tomatoes’ shoot length and weight, in contrast, Mk-20–20 produced HCN, siderophore, was able to fix nitrogen, improved tomato germination, shoot dry weight, and fruit weight. Various P-supplements (Ca3(PO4)2, bonemeal, FePO4, AlPO4, compost, and DAP fertilizer) were added to induce tomato-strain symbiotic interaction; hence, compost substantially promoted the interaction and resulted in higher symbiotic effectiveness. Ca3(PO4)2 was a good media composite preferred by most PSB strains; consequently, a higher concentration (219 µg/ml) of dissolved P was recorded from the liquid medium after 10 days of incubation than other substrates. Based on the data obtained from laboratory and greenhouse trials, the current strains were found to be potential candidate. Future work should confirm their efficacy at the field level using model host crops at different sites to recommend them as farm inputs and biofertilizer.

Fungal and enzymatic pretreatments of bamboo lignocellulose towards high-strength biocomposites: Biological macromolecule/enzyme interaction and bonding enhancement

An energy-intensive and chemical-consuming pretreatment of bamboo is often required to develop its high-performance composites. This study is to evaluate a fungal and enzymatic pretreatment as a sustainable surface modification approach towards high-strength bamboo biocomposites based on D. sinicus. Extracellular enzyme activity analysis suggested that the lignin oxidative enzyme and pectinase secreted by the white-rot fungus T. versicolor achieved higher reaction than the hydrolytic enzymes throughout the pretreatment. Chemical structure analysis revealed that lignin and hemicellulose were partially depolymerised and/or removed during the pretreatment, leading to a relatively higher cellulose content in D. sinicus. The analysis of physical property and microstructure suggested that the surface wettability and porosity of pretreated D. sinicus were significantly improved, facilitating the spreading and penetration of adhesive resins, which subsequently contributed to the superior interfacial bonding of the biocomposites. The tensile strength of the biocomposites increased from 195.8 MPa to 245.8 MPa and the bonding strength increased from 4.9 MPa to 6.3 MPa after the pretreatment, which were 1.26 times and 1.28 times those of the untreated biocomposite respectively. The results proved that the fungal and enzymatic pretreatment is a promising, eco-friendly and efficient surface modification approach for the preparation of high-strength lignocellulosic biocomposites.

Green synthesis of silver nanoparticles on polyamide fabrics using Scrophularia striata Boiss extract: Characterization, dyeing, and antibacterial properties

The green synthesis of silver nanoparticles (Ag NPs) on textiles using natural extracts is emerging as an innovative, eco-friendly approach for enhancing both antibacterial properties and dyeing performance. This study introduces a novel in-situ method for synthesizing Ag NPs directly on polyamide (PA) fabrics, utilizing Scrophularia striata Boiss extract (SBE) as a natural dye and reducing agent. UV–visible spectroscopy and dynamic light scattering (DLS) were used to characterize the synthesis process and determine the average particle size of Ag NPs. The data showed particle sizes of 62.5 nm and 56.1 nm when using flower and stem extracts, respectively. Surface morphology findings from scanning electron microscopy (SEM) and corresponding diffraction peaks in X-ray diffraction (XRD) confirmed the in situ formation of Ag NPs on the surface of PA fabric. Fabrics dyed with SBE and Ag NPs exhibited higher color strength (K/S values of 4.1 and 5.6 for flower and stem, respectively), showing 64 % and 100 % increases compared to samples without silver. Additionally, PA fabrics exhibited 100 % inhibition against E. coli and S. aureus bacteria. After 10 washing cycles, antibacterial activity was maintained at 88 % and 85 % for the stem extract and 83 % and 79 % for the flower extract. This research highlights the novel integration of natural dye and nanoparticle synthesis, providing a sustainable route for multifunctional textile development.

Optimization of ultrasound-assisted extraction of astaxanthin from black tiger shrimp (Penaeus monodon) shells using deep eutectic solvent and ethanol as a co-solvent

The study aimed to enhance the extraction of astaxanthin (ASX) from black tiger shrimp shells by combining Deep eutectic solvent (DES) and ultrasound-assisted extraction (UADE). The DES used in the research consisted of choline chloride (Ch) and citric acid (CA) in a 1:2 molar ratio with 20% water. Response surface methodology (RSM) utilizing a Box-Behnken design (BBD) was employed to optimize the UADE conditions, considering ultrasound power (200 – 400 W), ethanol concentration in the DES (5 – 65 %), and extraction time (5 – 45 min). The optimal UADE parameters identified by BBD were 330 W ultrasound power, 35% ethanol content, and 33 min of extraction, resulting in the highest ASX content of 47.42 μg/g, closely matching the predicted value of 48.65 μg/g. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis revealed structural alterations in samples treated with DES-based UAE, setting it apart from soxhlet extraction, maceration, and ethanol-based DES extraction. The outcomes indicated that UADE outperformed traditional extraction methods like soxhlet extraction, maceration, and ultrasound-assisted ethanol extraction (UAET) regarding ASX yield and antioxidant activity, while also needing shorter extraction durations. These results underscore UADE as a productive and eco-friendly approach for extracting ASX from shrimp shells.

Bio-inspired synthesis of ZnO nanoparticles using Taraxacum officinale for antibacterial, antifungal, and anticancer applications

A green synthesis method was developed to fabricate ZnO nanomaterials using Taraxacum officinale (Dandelion) leaf extract as a reducing agent and zinc sulfate heptahydrate as a precursor. Characterization by XRD, EDAX, FTIR, FESEM, and UV–vis spectroscopy confirmed the successful formation of ZnO nanocrystals with enhanced crystallinity following annealing. The ZnO nanomaterials exhibited significant bioactivity, demonstrating 85 % antibacterial efficiency against Escherichia coli and Staphylococcus aureus, along with 70 % antifungal activity. Furthermore, the nanomaterials showed promising anticancer effects, achieving a 60 % reduction in human cancer cell viability. This eco-friendly approach minimizes the use of toxic chemicals typically involved in nanoparticle synthesis, providing a sustainable alternative for producing functional oxide nanoparticles. The use of plant-based reducing agents not only makes the process safer and more biocompatible but also enhances the potential for biomedical applications. ZnO nanomaterials produced through this method offer great promise for antimicrobial therapies and cancer treatment. This efficient, green synthesis method can be further scaled for various applications, highlighting its relevance in fields such as nanomedicine, where bioactivity and eco-friendly synthesis are essential.

Kinetic study and optimization of ginger mediated ochratoxin A reduction: An eco-friendly approach including toxicity evaluation

Ochratoxin A (OTA) is a toxic secondary metabolite synthesized by certain fungal strains of Penicillium and Aspergillus and is characterized as a Group 2B carcinogen. OTA infiltrates food and feeds through diverse chains, posing health risks to humans and animals. Herein, seven distinct edible plant materials were screened for their OTA reduction activity. Amidst them, ginger juice in aqueous (2.5%, v/v) showed the highest OTA reduction (95.63%), following first-order reaction kinetics (R2 = 0.92) with 0.72 d−1 rate constant. OTA reduction activity of ginger juice was substantially compromised in the presence of salt (> 2.5%) and temperature (> 40 °C). The response surface methodology-based approach employing Box–Behnken experimental design revealed an integrated effect of temperature, pH, and salt concentrations on OTA reduction (27.44–100%) by ginger juice. In addition, heat treatment (100 °C) and dialysis (12–14 kDa cutoff) of ginger juice implied the inclusion of heat-stable small molecules in reducing OTA. Ginger-treated OTA ameliorated hepatocellular carcinoma (HepG2) cell viability and diminished reactive oxygen species (ROS) levels compared to native OTA. In zebrafish embryos, OTA-induced teratogenic effects, diminished hatching (22.91%), and elevated ROS levels leading to embryo mortality (75%), which was significantly reversed by OTA treated with ginger, underscoring the curtailed toxicity of OTA-converted products by ginger.

Development of protein hydrolysate as a cost-effective and robust biodispersant: Investigating its performance in dispersing of carbon black pigment in water-based paints

Carbon black pigments hold significant importance as the primary representatives of black pigments in the industry today. The dispersibility of carbon black pigment (CB) in water is limited by the nonpolar and weakly hydrophilic characteristics of the pigment's surface. Therefore, there is a critical need to devise an economical and eco-friendly approach for creating a well-dispersed and stable suspension of carbon black in an aqueous medium. The primary focus of this study was to investigate the dispersion capabilities of protein hydrolysate (HP) derived from sheep wool on CB particles in a water-based pigment concentrate. The hydrolysis degree of protein source was determined by high-performance liquid chromatography and gel permeation chromatography. The dispersion performance was investigated by zeta potential, transmission electron microscopy, Fourier transform infrared spectroscopy, grindometer, spectrophotometer-colorimeter, viscometer, and cryptometer measurements. The HP solution containing amino acids, peptides, and polypeptides with low molecular weight can cover the surface of the CB particles, creating enough electrical repulsion and steric resistance. As a result, this phenomenon can inhibit the collision and interaction among the pigment particles caused by Brownian motion, making it less prone to aggregation. The protein hydrolysate demonstrated a higher capability in producing the stable CB dispersions compared to a commercial reference dispersant, highlighting the effectiveness of amino acids, peptides, and polypeptides as powerful CB dispersing agents.

Controlled-Release Iodine Fertilizer Improved Iodine Accumulation, Antioxidant Capacity, and Quality of Lettuce

To clarify the effects of newly developed controlled-release iodine fertilizer (CRIF) on enhancing lettuce (Lactuca sativa L.) iodine accumulation, improving the physiological traits, and reducing iodine leaching from soil, a greenhouse pot experiment was conducted. Polymer-coated iodate (PCIO), polymer-coated iodide (PCI), and two conventional iodine fertilizers—iodate (CIO) and iodide (CI)—were applied at a rate of 15 mg iodine per kg soil. The study found that the coating of iodine fertilizers had no significant effects on the biomass of lettuce. The iodine concentration in lettuce leaves subjected to PCIO treatment was elevated by 50.1% and 45.5%, respectively, in comparison to leaves treated with CIO and PCI. The soil-to-leaf transfer factor (TFleaf, dry weight basis) for plants treated with PCIO was significantly higher than that of PCI-treated plants. PCIO also significantly reduced iodine leaching by 46.3% compared to CIO. In lettuce leaves with PCIO treatment, the enzymatic activities of superoxide dismutase (SOD) and catalase (CAT) significantly increased by 50.8% and 27.6%, respectively. Likewise, malo-naldehyde (MDA) levels decreased by 23.2% compared to the control samples. PCIO also demonstrated advantages in enhancing the quality of the lettuce. In conclusion, the application of controlled-release iodine fertilizer could be a highly effective and eco-friendly approach to cultivating iodine-rich vegetables.

UV-C-Activated Riboflavin Crosslinked Gelatin Film with Bioactive Nanoemulsion for Enhanced Preservation of Fresh Beef in Modified Atmosphere Packaging

This study explores a new eco-friendly approach for developing bioactive gelatin films using UV-C irradiation-induced photo-crosslinking. Riboflavin, a food-grade photoinitiator, was selected at an optimal concentration of 1.25% (w/w) for crosslinking gelatin under UV-C exposure for 4 to 22 min. Physicochemical analyses revealed enhanced tensile strength, reduced water vapor permeability, and lower water solubility in films crosslinked for up to 13 min. FTIR analysis demonstrated significant molecular changes, confirming the formation of crosslinking connections in gelatin–riboflavin films. Antimicrobial nanoemulsion (NE) (0.5, 0.75, 1% v/v) was incorporated into crosslinked films and applied to fresh beef. The 1% NE film exhibited the strongest antimicrobial effect, extending shelf-life by 20 days. In vitro release study confirmed Fickian diffusion behavior in the 1% NE film. This study also investigated the synergy between 1% NE film and three different types of modified atmosphere packaging (MAP) on the microbiological and physicochemical properties of beef for 26 days. The best results were achieved with 1% NE film under MAP1 and MAP2, which preserved meat redness and prevented lipid oxidation, extending the shelf-life up to 26 days. Therefore, UV-C irradiation-induced crosslinked bioactive film combined with high-oxygen MAP offers a promising solution for prolonging the shelf-life of beef.

ASSESSMENT OF NEWLY SYNTHESIZED SALICYLALDEHYDE-BASED SCHIFF BASES AS CORROSION INHIBITORS FOR CARBON STEEL IN AQUEOUS ENVIRONMENT

A novel and eco-friendly approach for synthesizing two salicylaldehyde-based Schiff bases (2HPP and BHBD) in aqueous environments has been successfully conducted. These synthesized Schiff bases were subjected to a range of physicochemical analyses, including CHNS elemental analyses, molar conductivity measurements, and spectroscopic techniques like IR, electronic, 1HNMR, and mass spectra, to ascertain their properties. The research also involved investigating the inhibitory properties of these Schiff bases against mild steel corrosion in hydrochloric acid solutions at a temperature of 30°C. The results obtained from this study revealed the remarkable inhibitory potential of 2HPP and BHBD on mild steel corrosion in HCl solution. The inhibition efficiency was found to increase with increasing concentration, ultimately reaching an impressive maximum inhibition efficiency of 91.50% and 94.54 % for 2HPP and BHBD, respectively. The adsorption behavior of 2HPP and BHBD followed the Langmuir isotherm, indicating a favorable interaction with the metal surface. Moreover, the investigations included the use of quantum chemical parameters, which were computed utilizing the Density Functional Theory (DFT) method. These calculations included energy gap assessments, which lent support to the excellent inhibiting performance of both Schiff basses. However, BHBD appeared to be a more efficient inhibitor than 2APP.

Strategies for Hydrocarbon Removal and Bioleaching-Driven Metal Recovery from Oil Sand Tailings

Oil sand tailings from bitumen extraction contain various contaminants, including polycyclic aromatic hydrocarbons, BTEX, and naphthenic acids, which can leak into surrounding environments, threatening aquatic ecosystems and human health. These tailings also contribute to environmental issues such as habitat disruption and greenhouse gas emissions. Despite these challenges, oil sand tailings hold significant potential for waste-to-resource recovery as they contain valuable minerals like rare earth elements (REEs), titanium, nickel, and vanadium. Traditional metal extraction methods are environmentally damaging, requiring high energy inputs and generating dust and harmful emissions. Furthermore, the coating of hydrocarbons on mineral surfaces presents an additional challenge, as it can inhibit the efficiency of metal extraction processes by blocking access to the minerals. This highlights the need for alternative, eco-friendly approaches. Bioleaching, which uses microorganisms to extract metals, emerges as a sustainable solution to unlock the valuable metals within oil sand tailings. This review discusses the minerals found in oil sand tailings, the challenges associated with their extraction, methods from hydrocarbon removal from minerals, and bioleaching as a potential metal recovery method.

Eco-Friendly Green Approach to the Biosorption of Hazardous Dyes from Aqueous Solution on Ragweed (Ambrosia artemisiifolia) Biomass

The presented research includes the preparation, characterization, and implementation of magnetic biosorbent (Fe3O4/RWB), obtained from ragweed (Ambrosia artemisiifolia) biomass. Fe3O4/RWB was examined for the removal of a hazardous dye, malachite green (MG), from an aqueous solution in a batch system. The effects of the experimental parameters—initial dye concentration (10–300 mg/L), contact time (0–120 min), biosorbent dose (1–5 g/L), initial pH (2–10), ionic strength (0–1 mol/L), and temperature (298–318 K) on dye biosorption—were studied. The results showed that increases in biosorbent dose, contact time, and initial pH led to an increase in biosorption efficiency, while the increase in initial dye concentration, the ionic strength, and temperature had the opposite effect. The biosorption kinetics for MG on Fe3O4/RWB were analyzed with pseudo-first-order, pseudo-second-order, and Elovich kinetic models, while the Langmuir, Freundlich and Temkin isotherm models were used for equilibrium data analysis. It was observed that the MG biosorption followed the pseudo-second-order kinetic model, whereas the Langmuir model was the best fit for the equilibrium biosorption data of MG, with a Qmax of 34.1 mg/g. the desorption of MG from Fe3O4/RWB indicated reusability in five adsorption/desorption cycles, good performance, and potential in practical applications.

Characterization of green-synthesized carbon quantum dots from spent coffee grounds for EDLC electrode applications

This study investigates the green synthesis of carbon quantum dots (CQDs) from spent coffee grounds using a hydrothermal method, offering an eco-friendly, cost-effective, and straightforward approach to nanomaterial production. The synthesized CQDs, with particle sizes ranging from 1.6 to 4.4 nm, exhibited notable fluorescence, achieving quantum yields of 37.0 %, 54.3 %, and 63.3 % depending on the coffee source. Characterization technique, including XRD, FTIR, SEM, TEM, and BET, confirmed their structural suitability of these CQDs for energy storage applications. Their electrochemical performance was evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Among the CQDs tested, those derived from spent Liberica coffee ground (medium roasted) demonstrated superior performance, with a discharging specific capacitance of 97.5 F/g, an energy density of 4.3 Wh/kg, and a power density of 130.6 W/kg at a current density of 0.5 A/g. Additionally, they exhibited acceptable internal resistance (Ra = 0.01 kΩ and Rab = 16.9 kΩ), indicating favourable charge transfer characteristics. These results underscore the enhanced energy storage potential of CQDs derived from spent coffee grounds. The findings not only highlight the excellent electrochemical performance but also support the viability of biomass waste as a valuable resource for advanced energy storage applications, promoting sustainable, eco-friendly technologies.