Search Results (12,152)

This study develops biodegradable chitosan (CS) films plasticized with natural deep eutectic solvents (NaDES) composed of choline chloride and glycolic acid (1:3 molar ratio). The same NaDES served as an effective extraction medium for bioactive compounds from hawthorn (Crataegus monogyna), which were incorporated into the chitosan matrix to enhance functionality. CS films with 44–70 wt% NaDES were evaluated, and the 50 wt% formulation exhibited the optimal mechanical and barrier performance. Upon extract incorporation, this film showed marked decreases in Young’s modulus (131→30 MPa) and tensile strength (24→12 MPa), relative to the extract-free counterparts, indicating enhanced flexibility. Stress–strain analyses confirmed a progressive reduction in stiffness with increasing NaDES content, evidencing its plasticizing effect. FTIR analysis revealed extensive hydrogen-bonding between CS and NaDES, alongside successful integration of polyphenolics extracted from hawthorn. Morphological analysis showed smooth, dense, homogeneous surfaces. Films exhibited strong UV absorption, with extract-loaded samples extending into the UVA and visible ranges, enhancing light-barrier properties. The presence of polyphenolic compounds enhanced the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity to nearly twice that of the neat CS films. These combined mechanical, optical, and antioxidant properties highlight the potential of these NaDES-based chitosan films for sustainable active packaging. Full article

Alginate-based microcapsules have gained considerable attention as drug delivery systems due to their biocompatibility, biodegradability, and ability to encapsulate therapeutic agents. In this study, microcapsules were synthesized by crosslinking with calcium ions, with albumin serving as a carrier for doxorubicin. The goal was to develop a stable system capable of controlled drug release under physiological conditions, with potential applications in cancer therapy. Sodium alginate was used as a base polymer, which formed a stable matrix after crosslinking with calcium ions. The resulting microcapsules showed a uniform size distribution in the microscale range. Analyses confirmed their stability in simulated physiological environments with minimal degradation. Observations revealed a homogeneous structure of the microcapsules, while incubation studies confirmed controlled drug release triggered by pH changes. The results indicate that alginate–albumin microcapsules can serve as an effective platform for drug delivery, especially in cancer therapy and other biomedical applications. Full article

High-nitrogen organic chemical wastewater is characterized by high chemical oxygen demand (COD_Cr), poor biodegradability, and toxic nitrogenous organics, posing significant challenges for conventional biological treatment. In this study, a dual-electrical treatment strategy integrating an electromagnetic Fenton (EM-Fenton) pretreatment unit with a three-dimensional biofilm electrode reactor (3D-BER) is proposed. The EM-Fenton system used iron–carbon fillers under electric and magnetic fields to generate hydroxyl radicals (·OH), enabling efficient oxidation of nitro-aromatic compounds and the conversion of organic nitrogen into NO₃⁻-N, while reducing Fe²⁺ input and iron sludge generation. Subsequently, the 3D-BER, filled with Fe₃O₄/Mn₃O₄-modified polyurethane spheres, facilitated autotrophic denitrification and phosphorus removal through enhanced extracellular electron transfer and trace hydrogen (H₂) release. Experimental results demonstrated that the EM-Fenton system achieved COD_Cr and NH₄⁺ removal rates of over 40% and 14%, respectively, under optimal HRT. The 3D-BER further improved removal efficiencies, with TN and TP reductions exceeding 80% and 81%, respectively, significantly outperforming the control groups. Microbial analysis revealed the enrichment of functional genera, such as Pararhodobacter and Thauera, and the upregulation of key denitrification pathways. This coupled system demonstrated high treatment efficiency, process synergy, and microbial selectivity, offering a promising approach for the advanced treatment of high-nitrogen industrial wastewater. Full article

Blow spinning is a low-cost and versatile method that permits the large-scale production of fibrous membranes. However, polysaccharides that show numerous merits such as biocompatibility and biodegradability often have a low spinnability due to their high chain rigidity and low ability to form sufficient entanglements. Here, we report the fabrication of polysaccharide micro-fibrous membranes from sodium alginate/polyethylene oxide solutions formulated in solvent mixtures of water and ethanol. The shear and extensional rheological responses of the solutions are characterized, and parameters including specific shear viscosity, reptation time, extensional relaxation time, and maximum stretch ratio are correlated with the concentrations of polymer, polyethylene oxide, and ethanol. It is found that flexible polyethylene oxide and poorer solvent ethanol can synergistically delay the chain relaxation during stretch and increase the stretchability of the solutions. A processability map of the solutions for blow spinning is constructed, enabling the fabrication of fibrous membranes with a fiber diameter of ~1 μm, tensile strength of 4.89 MPa, elongation at break of 15.24%, and Young’s modulus of 45.43 MPa. This study presents a new strategy to fabricate sodium alginate-based membranes, which should provide insights into the design of other polysaccharide membranes with specific functions and applications. Full article

Gelatin-based hydrogels are promising materials for pharmaceutical and biomedical applications due to their biocompatibility, biodegradability, and tunable gel-forming behavior. However, their thermo-sensitivity and limited processability often restrict their practical use in advanced drug delivery or tissue engineering systems. In this study, low-molecular-weight gelatin (LMWG) was obtained from native gelatin through controlled degradation with hydroxylamine, aiming to enhance processability while maintaining functional amino groups for crosslinking. Hydrogels prepared from both native gelatin and LMWG were crosslinked with genipin, a natural and biocompatible compound, and comprehensively characterized in terms of structural, mechanical, and biological properties. LMWG exhibited superior processability, remaining liquid at room temperature, which facilitates the preparation of different formulations and the potential incorporation of bioactive compounds into the crosslinked hydrogels. Compared with gelatin-genipin hydrogels, LMWG-genipin hydrogels showed higher swelling capacity, slightly increased porosity, and improved flexibility without significant loss of mechanical integrity. Rheological analysis confirmed both hydrogels’ viscoelastic properties with differences in their thermo-sensitive behavior. Cytocompatibility assays using L929 fibroblasts demonstrated low toxicity as well as proliferation of cells seeded on the materials. Overall, the combination of molecular weight modulation and crosslinking by genipin provides a simple and effective strategy to develop gelatin-based hydrogels suitable for pharmaceutical formulations, tissue-engineering scaffolds, and controlled-release systems. Full article

Microplastics (MPs) have emerged as persistent and ubiquitous contaminants in aquatic and terrestrial environments, yet existing reviews often focus narrowly on conventional removal methods and lack an integrated assessment of rapidly emerging technologies. This review addresses this critical gap by providing a comprehensive and comparative synthesis of both established and next-generation approaches for MP removal from water and wastewater systems. Conventional methods such as coagulation–flocculation, sedimentation, and filtration are compared with advanced approaches including membrane separation, adsorption using engineered biochar and nanomaterials, advanced oxidation processes (AOPs), and biodegradation using microbial or enzymatic pathways. Particular emphasis is placed on hybrid and integrated systems, an area seldom summarized in prior reviews, highlighting their synergistic potential to enhance removal efficiency, reduce energy demand, and improve operational stability. Promising front-runner technologies including membrane filtration coupled with coagulation pretreatment and biochar-based magnetic adsorption systems have been identified based on a balanced performance across the key criteria of removal efficiency, scalability, energy demand, cost, byproduct risk, and environmental sustainability. The review concludes by outlining key research priorities such as standardized testing protocols, scalable biophysicochemical integration strategies, and sustainability-oriented life-cycle assessments to guide future innovation in MP management. Full article

Biodegradable microplastics can adsorb organic pollutants in aquatic environments, worsening contamination. However, the molecular mechanisms behind this association remain poorly understood. This study employs molecular dynamics (MD) simulations and density functional theory (DFT) calculations to systematically explore the molecular interactions between polylactic acid (PLA) and the herbicide acetochlor (ACT) in freshwater and a seawater analog. Our simulations reveal that PLA demonstrates a notably higher adsorption capacity for organic pollutants in seawater than in pure water. This improvement stems from three main factors: (i) PLA forms a more compact microstructure under saline conditions, (ii) its specific surface area increases, offering more active adsorption sites, and (iii) surface adsorption between PLA and ACT molecules dominates. DFT calculations support the MD simulation findings, demonstrating stronger PLA–ACT interaction energies in seawater. The adsorption process is mainly driven by two fundamental mechanisms: van der Waals forces and hydrogen bonding. Importantly, dissolved salt ions in seawater act as molecular bridges, facilitating interactions between PLA and ACT. Based on these insights, the study proposes conservative, testable risk indicators and planning/management implications for coastal drainage infrastructure, contributing to broader sustainable development objectives. Full article

C footprint is a feature used to search the integral life cycle of a product to predict its environmental impact. The packaging industry is changing rapidly to the production of biodegradable products to mitigate the negative environmental consequences of the use of single-use packages. It is thought that biodegradable packages should be more sustainable than traditional plastics due to the sources of the raw materials used to produce them, but this is not always true and depends on the issues considered, the methodology, and the scale analyzed. Limited research includes case studies from developing countries where waste management is less efficient and where the environmental impacts of single-use packaging can be more significant. This paper evaluates the C footprint of bags and dishes made from traditional or local biodegradable sources in an Amazonian settlement of Colombia, such as thermoplastic cassava starch and powdered plantain leaves, to evaluate the impact of locally made biodegradable packaging vs. imported petrochemical ones. Results show that using local raw materials and in situ production reduces the C footprint of biodegradable packages, considering that the energy source for production and transport are important contributors to the C footprint beyond the raw materials used, with ratios that can be between 0.1 and 7 times more kg CO₂ eq generated per functional unit. Full article

Objective. To determine how bamboo loadings (2.5–5 wt%) and compatibilization with PBAT-g-MAH (BP-1, 10 wt%) affect melt flow and early-time mineralization of PLA biocomposites under near-ambient soil–compost conditions (ASTM D5988), while using PBAT-g-GMA (BP-2) only as a melt-flow screening reference. Methods. Melt flow index (MFI, ASTM D1238, 2.16 kg; 190/210/230 °C) was first measured for neat PLA and PLA/BP-1/BP-2 blends to select a printable matrix. PLA/10BP-1 composites containing 2.5–5 wt% bamboo were then compounded, extruded as bars for biodegradation tests, and validated by FFF printing. Biodegradation was quantified from titrimetric CO₂ evolution in soil–compost reactors at 21 ± 2 °C and pH ≈ 7 (triplicate specimens plus triplicate blanks; mean ± SD and endpoint statistics). ATR-FTIR was used to support mechanistic interpretation. Results. BP-1 markedly increased MFI relative to neat PLA, whereas BP-2 remained close to the neat matrix, consistent with epoxy-driven coupling that can raise viscosity. Under ambient burial, all materials exhibited very low mineralization over 0–23 days; PLA/10BP-1/2.5B and PLA/10BP-1/5B showed a slight increase in net CO₂ evolution compared with neat PLA, but the differences remained modest and within the experimental uncertainty, reflecting a balance between bamboo’s pro-hydrolytic effect and the sealing action of PBAT-g-MAH compatibilization. Significance. The data delineate a printing–degradation window in which PLA/10BP-1 with 2.5–5 wt% bamboo combines easy processing and short-term durability while preserving industrial compostability at end-of-life. Full article

This study focuses on improving the fatigue strength and overall performance of sustainable biopolymer polylactic acid (PLA) components manufactured via Fused Deposition Modelling (FDM) additive manufacturing process. PLA, as a biodegradable and renewable polymer derived from natural resources, represents a promising alternative to conventional petroleum-based plastics in engineering and research applications. The influence of key FDM process parameters—layer height, infill density, and number of perimeters—on critical performance indicators such as filament consumption, printing time, and fatigue strength (number of cycles to failure) was systematically analyzed using the Taguchi L9 orthogonal array. Subsequently, Grey Relational Analysis (GRA) was applied as a multi-objective optimization technique to identify the parameter settings that achieve an optimal balance between mechanical durability and resource efficiency. The obtained results demonstrate that a proper combination of process parameters can significantly enhance the mechanical reliability and sustainability profile of FDM-printed PLA parts, contributing to the broader adoption of eco-friendly materials in additive manufacturing. Full article

The increasing emphasis on green chemistry has led numerous researchers to focus on environmentally friendly solvents for mineral extraction. Among them, deep eutectic solvents (DESs) have garnered significant attention due to their eco-friendly, non-toxic, and biodegradable properties. These solvents possess comparable physicochemical properties to conventional ionic liquids but are more cost-effective and environmentally friendly. While DESs have been widely studied for extracting metals from synthetic minerals and end-of-life products, its use with primary ores and associated wastes remains relatively unexplored. This study aims to bridge that gap by assessing the effectiveness of choline chloride- and ethylene glycol-based DESs in extracting rare earth elements from primary feedstocks with varied grades and mineralogy, including sub-economic ores, monazite flotation tailings, and acid-crack and leach residue. The study also examines the practical challenges in preparing DES and assesses the applicability of the solvents for primary materials. By examining both solvent preparation challenges and the variable responses of different feed materials, this work provides a high-level scoping analysis to better understand the suitability and limitations of DES for primary resource extraction. This study highlights the challenges with physical properties and mineral breakdown in using DES. Full article

Biosurfactants (BSs) are natural, biodegradable compounds crucial for replacing synthetic emulsifiers in the food industry, provided their production costs can be reduced through the use of sustainable and low-cost substrates. This study evaluated the viability of licuri oil as a carbon source for BS production by Candida utilis and assessed the product’s functional stability in food formulations. Production kinetics confirmed the yeast’s efficiency, reducing the water surface tension to a minimum of 31.55 mN·m⁻¹ at 120 h. Factorial screening identified a high carbon-to-nitrogen ratio as the key factor influencing ST reduction. The isolated BS demonstrated high surface activity, with a Critical Micelle Concentration of 0.9 g·L⁻¹. Furthermore, the cell-free broth maintained excellent emulsifying activity (E₂₄ > 70%) against canola and motor oils across extreme pH, temperature, and salinity conditions. Twelve mayonnaise-type dressings were formulated, utilizing licuri oil, and tested for long-term physical stability. Six formulations, featuring the BS in combination with lecithin and/or egg yolk, remained stable without phase segregation after 240 days of refrigeration, maintaining a stable pH and suitable microbiological conditions for human consumption. The findings confirm that the valorization of licuri oil provides a route to produce a highly efficient and robust BS, positioning it as a promising co-stabilizer for enhancing the shelf-life and natural appeal of complex food emulsions. Full article

Citrus fruits are among the most important global crops, with annual production exceeding 160 million tons. Processing produces significant waste, mainly peels, seeds, and pulp, which can make up to fifty percent of the fruit’s mass. This review critically examines innovative ways to valorize these byproducts. Recent research shows that peels, seeds, and pulp can be converted into high-value materials, including biocomposites and biomaterials, marking a shift from traditional uses like animal feed and biogas production. Notable innovations include smart packaging, pectin-based wound dressings, and biodegradable polymers for sustainable electronics. Advanced green extraction methods, such as deep eutectic solvents, have achieved extraction yields over 85% for flavonoids. Additionally, multifunctional biorefineries processing citrus and olive residues have increased biogas yields by 38–42%. The review explores emerging applications in nanotechnology, nutraceuticals, biodegradable polymers, and functional coatings, all aligned with principles of circular economy and green chemistry. These advances suggest that citrus waste can play a significant role in sustainability efforts and new market development. The review also discusses barriers to adoption, including scalability challenges, regulatory limits, and consumer acceptance, from both global and regional viewpoints. Full article

The recovery of critical metals from spent lithium-ion batteries (LIBs) is essential to reduce environmental impacts and promote circular economy strategies. This study developed a sustainable and scalable process for the recovery and complete valorization of lithium, cobalt, and other valuable components from end-of-life LIBs. Hydrometallurgical treatment using biodegradable citric and oxalic acids was employed as a green alternative to conventional inorganic acids, achieving high selectivity and reduced environmental impact. Experimental work was conducted on 3 kg of LIBs from discarded laptop batteries (Dell and HP). After safe discharge and dismantling, the cathode materials were thermally treated at 300 °C to detach active components, followed by acid leaching in 1 M citric acid at 30 °C, pH 2.5, and 6 h of reaction. Lithium and cobalt were recovered as oxalates with efficiencies of 90% and 85%, respectively, while copper, aluminum, and graphite were separated through mechanical and thermal processes. Beyond metal recovery, the process demonstrates a circular upcycling approach, transforming recovered materials into functional products such as aluminum keychains, copper jewelry, and graphite-based pencils. This integrated strategy connects hydrometallurgical extraction with material reuse, advancing toward a zero-waste, closed-loop system for sustainable LIB recycling and local resource valorization. Full article

It is well known that elevated phosphate concentrations in water bodies trigger the eutrophication process, posing adverse environmental, health, and economic consequences that necessitate effective removal solutions. Phosphate removal has therefore been widely studied using various methods, including chemical precipitation, membrane filtration, and crystallisation. However, most of these methods are often expensive or inefficient for low phosphate concentrations. Therefore, in this study, an eco-friendly, sustainable and biodegradable adsorbent was manufactured by extracting calcium ions from an industrial by-product, ground granulated blast furnace slag (GGBS) and magnesium ions from magnesium dross (MgD), then immobilising them on sodium alginate to form Ca-Mg-SA beads. The new adsorbent was applied to remove phosphate from water under different flow patterns (batch and continuous flow), initial pH levels, contact times, agitation speeds and adsorbent doses. Additionally, the degradation time of the new adsorbent, recycling potential, its morphology, formation of functional groups and chemical composition were investigated. The results obtained from batch experiments demonstrated that the new adsorbent achieved 90.2% phosphate removal efficiency from a 10 mg/L initial concentration, with a maximum adsorption capacity of 1.75 mg P/g at an initial pH of 7, a contact time of 120 min, an agitation speed of 200 rpm and an adsorbent dose of 1.25 g/50 mL. The column experiments demonstrated a 0.82 mg P/g removal capacity under the same optimal conditions as the batch experiments. The findings also showed that the adsorption process fitted well to the Freundlich and Langmuir isotherm models and followed a pseudo-second-order kinetic model. Characterisation of Ca-Mg-SA beads using EDX, SEM and FTIR confirmed successful ion immobilisation and phosphate adsorption. Furthermore, the beads fully biodegraded in soil within 75 days and demonstrated potential recycling as a fertiliser. Full article