Search Results (887)

In rural Ghana, limited access to affordable, clean cooking fuels drives the need for decentralised waste-to-energy solutions. Anaerobic co-digestion (AcoD) offers a viable route for transforming organic residues into renewable energy, with the added benefit of improved process stability resulting from substrate synergy. This study aims to evaluate the technical feasibility and stabilisation challenges of AcoD, using locally available fruit waste and beet molasses at a secondary school in Bedabour (Ghana). Biological methane potential (BMP) assays of different co-digestion mixtures were conducted at two inoculum-to-substrate (I/S) ratios (2 and 4), identifying the highest yield (441.54 ± 45.98 NmL CH₄/g VS) for a mixture of 75% fruit waste and 25% molasses at an I/S ratio of 4. Later, this mixture was tested in a 6 L semi-continuous AcoD reactor. Due to the high biodegradability of the substrates, volatile fatty acid (VFA) accumulation led to acidification and process instability. Three low-cost mitigation strategies were evaluated: (i) carbonate addition using eggshell-derived sources, (ii) biochar supplementation to enhance buffering capacity, and (iii) the integration of a bioelectrochemical system (BES) into the AcoD recirculation loop. The BES was intended to support VFA removal and enhance methane recovery. Although they temporarily improved the biogas production, none of the strategies ensured long-term pH stability of the AcoD process. The results underscore the synergistic potential of AcoD to enhance methane yields but also reveal critical stability limitations under high-organic-loading conditions in low-buffering rural contexts. Future implementation studies should integrate substrates with higher alkalinity or adjusted organic loading rates to ensure sustained performance. These findings provide field-adapted insights for scaling-up AcoD as a viable renewable energy solution in resource-constrained settings. Full article

This study investigated the aerobic biodecolorization of azo dyes by Shewanella oneidensis MR-1. S. oneidensis MR-1 can rapidly degrade azo dyes under aerobic conditions, even at high concentrations of up to 270 mg/L, demonstrating remarkable dye decolorization capabilities. This decolorization efficiency persists even under high concentrations of oxygen. The introduction of different environmental metal ions led to either inhibitory or stimulatory effects on the decolorization of Methyl Orange and Amaranth. Furthermore, the addition of extracellular electron shuttles and electron scavengers confirmed that dyes were being reduced via electron transfer, and the decolorization capability of S. oneidensis MR-1 correlated with electron density. Our study unveils the rapid degradation ability of S. oneidensis MR-1 for dyes under aerobic conditions, which is closely linked to its electron transfer capacity. This research holds significant implications for a deeper understanding of the biodegradation mechanisms of azo dyes under aerobic conditions. Full article

Development of biodegradable packaging materials and valorization of agri-food waste are necessary to produce more sustainable materials while reducing the environmental impact. Starch-based biocomposite films reinforced with beer bagasse fractions with different purification degrees were developed and characterized in structural, mechanical, thermal and optical properties. To this aim, 5% and 10% (w/w) of either beer bagasse (BB) or its lignocellulosic-rich fibers (LF), obtained by subcritical water extraction at temperatures between 110 and 170 °C, were incorporated into starch matrices. Elastic modulus and tensile strength values increased by up to eight-fold and 2.5-fold, respectively, compared to the control film. The incorporation of BB or LF significantly enhanced the mechanical resistance of the films. In general, the increment in the filler:polymer ratio significantly increased the EM values (p < 0.05), while decreasing the stretchability of the films around 80–85%, regardless of the type of filler. This effect suggests a good interfacial adhesion between the fillers and the polymeric matrix, as observed by FESEM. The biocomposite films exhibited a dark reddish appearance, reduced transparency, light blocking barrier capacity and remarkable antioxidant activity due to the presence of phenolic compounds in the fibers. The water vapor and oxygen barrier properties were better preserved when using the more purified LF obtained at 170 °C. Overall, starch films reinforced with beer bagasse fractions showed strong potential for the development of biodegradable food packaging materials. Full article

Biodegradable hydroretentive polymers, such as UPDT^®, have emerged as promising alternatives to synthetic hydrogels, particularly in pasture systems where sustainable water management is crucial. These materials enhance subsurface drip irrigation by maintaining soil moisture, which supports germination and early root development until roots access deeper water reserves. However, their degradation dynamics in tropical forage systems remain poorly characterized, posing a challenge to long-term application strategies. This study aimed to evaluate the effects of different UPDT^® doses (0, 7.5, 15, 22.5, and 30 kg ha⁻¹) on the morphological and agronomic traits of Mombaça grass under controlled conditions. After a uniformity cycle, treatments were evaluated across four cultivation cycles with monitored irrigation to avoid water deficits. Morphogenetic traits such as number of live leaves (NLL), final number of emerging leaves (NEmL), leaf appearance rate (LAR), and stem elongation rate (SER), as well as shoot dry mass (SDM), were analyzed. Results showed that morphological variables responded quadratically to polymer doses during the initial and intermediate cycles. In the final cycle, reductions in these traits and in water productivity suggested the onset of polymer degradation and loss of hydroretentive capacity. Agronomic traits were influenced throughout all cycles, with the fourth cycle showing the highest SDM due to elevated temperatures. These findings highlight the need to better understand the degradation kinetics of biodegradable hydrogels such as UPDT^® in tropical pastures. Field trials are recommended to define optimal reapplication intervals and integrate degradation monitoring into irrigation planning, ensuring long-term sustainability in pasture management. Full article

The increasing demand for sustainable building solutions has directed attention toward bio-based materials, among which mycelium bio-composites (MBCs) have emerged as promising alternatives to traditional insulation materials. Grown from fungal mycelium and lignocellulosic waste, MBCs offer low embodied energy, biodegradability, and effective hygrothermal performance. This review assesses the current state of the art in MBC fabrication and hygrothermal properties, encompassing both laboratory-scale and industrial methods. MBCs demonstrate thermal conductivity values in the range of 0.036–0.06 W·m⁻¹·K⁻¹, moisture buffering capacity comparable to plant-fiber composites, and up to 70% lower embodied carbon than conventional materials. Key challenges are identified, including process standardization, scalability, and durability under real-world conditions. These composites also offer moisture buffering, compostability, and design flexibility. Moreover, recent advancements in additive manufacturing and microstructural optimization suggest a path toward broader adoption of MBCs in construction. By highlighting critical technical and scientific developments, this review identifies targeted research priorities, including the development of standardized fabrication protocols, quantitative lifecycle assessment of MBCs across varying climates, and strategies to scale up production while maintaining mechanical and hygrothermal consistency. Full article

The increasing demand for food necessitates that agri-food systems adopt innovative techniques to enhance food production while optimizing the use of limited resources, such as water. In agriculture, hydrogels are being increasingly used to enhance water retention and reduce irrigation requirements. However, most of these materials are based on synthetic polymers that are not biodegradable. This raises serious environmental and health concerns, highlighting the urgent need for sustainable, biodegradable alternatives. Biomass-derived from agro-industrial waste presents a substantial potential for producing hydrogels, which can effectively function as water collectors and suppliers for crops. This review article provides a comprehensive overview of recent advancements in the application of agro-industrial waste for the formulation of hydrogels. Additionally, it offers a critical analysis of the development of hydrogels utilizing natural and compostable materials. Agro-industrial and food waste, which are rich in hemicellulose and cellulose, have been utilized to enhance the mechanical properties and water absorption capacity of hydrogels. These biomaterials hold significant potential for the development of effective hydrogels in agricultural applications; they can be either hybrid or natural materials that exhibit efficacy in enhancing seed germination, improving water retention capabilities, and facilitating the controlled release of fertilizers. Natural hydrogels derived from agro-industrial waste present a sustainable technological alternative that is environmentally benign. Full article

In light of the environmental impact of disposable products made from petroleum-based plastics, this study focused on developing biodegradable foam trays made from a starch (PS) derived from potato waste and beer malt flour (BMBF). The objective of this study was to evaluate the effect of the concentration of BMBF on the physical and mechanical properties of potato starch-based foam trays prepared by the thermoforming process at temperatures of 150 °C (upper plate) and 145 °C (lower plate) for 5 min and 40 s. The results showed that increasing the BMBF concentration from 0 to 40% reduced the moisture content from 4.68% to 3.42%, increased the thickness from 2.63 cm to 4.77 cm, and decreased the density from 0.28 g.cm⁻³ to 0.15 g.cm⁻³. Meanwhile, the water absorption capacity increased from 38.7% to 69.7%. In terms of mechanical properties, increasing the BMBF concentration in the PS foam tray resulted in a decrease in hardness from 5.61 N to 2.87 N, a decrease in tensile strength from 2.92 MPa to 0.85 MPa, and a decrease in elongation from 1.42% to 0.59%. Meanwhile, fracturability increased from 2.04 mm to 3.68 mm. FTIR analysis revealed interactions between BMBF and PS in the composite foam tray. Thermogravimetric analysis (TGA) showed two thermal events: one between 20.96 °C and 172.89 °C, and another between 189.14 °C and 517.69 °C, with weight losses of 5.53% and 74.23%, leaving an ash residue of 20.24%. Differential calorimetry analysis (DSC) showed a glass transition at 152.88 °C and a melting at 185.94 °C, with an enthalpy of fusion of 74.11 J.g⁻¹. Higher concentrations of BMBF (>10%) decreased the water resistance, mechanical strength, and flexibility of the PS foam trays. Therefore, a formulation of 90% PS and 10% BMBF was better for producing a foam tray with improved mechanical properties and water resistance, which could be used as a sustainable alternative to conventional single-use plastic. Full article

We report an investigation on the cobalt(II) chelation mechanism by a modified α-maltoside ligand 9 decorated with two iminodiacetate (IDA) residues on C6,C6′ positions. Herein we uncovered the capacity of this biodegradable ligand to chelate cobalt(II), an ionic metal contaminant in the environment that is used, in particular, in lithium-ion batteries. The interactions between cobalt(II) and synthesized ligand 9 were systematically studied using different analytical methods such as ¹H and ¹³C NMR, potentiometry, spectrophotometry, ITC, and ICP-AES. We observed a high affinity for the 1:1 complex, one cobalt(II) associated with two iminodiacetate groups, which is 10-fold higher than the 2:1 complex, where each of the two IDA groups interacts alone with a cobalt(II). Taking into account the log β_CoL value obtained (≈12.3) with the stoichiometry 1:1, the strength of this complexation with cobalt(II) can be ranked as follows for the most common ligands: IDA < MIDA < NTA < 9 < EDTA < TTHA < DTPA. We further completed a preliminary remediation test with water contaminated with cobalt(II) and recovered cobalt(II) metal using Chelex^® resin, which allowed a recycling of the synthetic ligand for future recovering experiments. The results shed light on the great potential of using this synthetic ligand as an effective and green remediation tool. Full article

Concern over the presence of pharmaceutical waste in the environment has prompted research into the management of emerging organic micropollutants (EOMs). In response, sustainable technologies have been applied as alternatives to reduce the effects of these contaminants. This study investigated the capacity of filamentous fungi isolated from iron mine soil in the Amazon region to biodegrade the drug chloroquine diphosphate. An initial screening assessed the growth of four fungal strains on solid media containing chloroquine diphosphate: Trichoderma pseudoasperelloides CBMAI 2752, Penicillium rolfsii CBMAI 2753, Talaromyces verruculosus CBMAI 2754, and Penicillium sp. cf. guaibinense CBMAI 2758. Among them, Penicillium sp. cf. guaibinense CBMAI 2758 was selected for further testing in liquid media. A Box–Behnken factorial design was applied with three variables, pH (5, 7, and 9), incubation time (5, 10, and 15 days), and chloroquine diphosphate concentration (50, 75, and 100 mg·L⁻¹), totaling 15 experiments. The samples were analyzed by gas chromatography–mass spectrometry (GC-MS). The most effective conditions for chloroquine biodegradation were pH 7, 100 mg·L⁻¹ concentration, and 10 days of incubation. Four metabolites were identified: one resulting from N-deethylation M1 (N4-(7-chloroquinolin-4-yl)-N1-ethylpentane-1,4-diamine), two from carbon–carbon bond cleavage M2 (7-chloro-N-ethylquinolin-4-amine) and M3 (N1,N1-diethylpentane-1,4-diamine), and one from aromatic deamination M4 (N1-ethylbutane-1,4-diamine) by enzymatic reactions. The toxicity analysis showed that the products obtained from the biodegradation of chloroquine were less toxic than the commercial formulation of this compound. These findings highlight the biotechnological potential of Amazonian fungi for drug biodegradation and decontamination. Full article

Hydrogels exhibit remarkable physicochemical properties, including high water absorption and retention capacities, as well as controlled release behavior. Their inherent biodegradability, biocompatibility, and non-toxicity make them suitable for a wide range of applications. Cellulose, a biodegradable, renewable, and abundantly available polysaccharide, is a viable source for hydrogel preparation. Ionizing radiation, using electron-beam (EB) or gamma (γ) irradiation, provides a promising approach for synthesizing hydrogels. This study reviews recent advancements in cellulose-based hydrogels, focusing on cellulose and its derivatives, brief information regarding ionizing radiation, comparison between EB and γ-irradiation, synthesis and modification through ionizing radiation technology, and their environmental and agricultural applications. For environmental remediation, these hydrogels have demonstrated significant potential in water purification, particularly in the removal of heavy metals, dyes, and organic contaminants. In agricultural applications, cellulose-based hydrogels function as soil conditioners by enhancing water retention and serving as carriers for agrochemicals. Full article

The cosmetics industry has been seeking to develop products with renewable natural ingredients to reduce the use of or even replace synthetic substances. Biosurfactants can help meet this demand. These natural compounds are renewable, biodegradable, and non-toxic or have low toxicity, offering minimal risk to humans and the environment, which has attracted the interest of an emerging consumer market and, consequently, the cosmetics industry. The aim of the present study was to produce a biosurfactant from the yeast Starmerella bombicola ATCC 22214 cultivated in a mineral medium containing 10% soybean oil and 5% glucose. The biosurfactant reduced the surface tension of water from 72.0 ± 0.1 mN/m to 33.0 ± 0.3 mN/m after eight days of fermentation. The yield was 53.35 ± 0.39 g/L and the critical micelle concentration was 1000 mg/L. The biosurfactant proved to be a good emulsifier of oils used in cosmetic formulations, with emulsification indices ranging from 45.90 ± 1.69% to 68.50 ± 1.10%. The hydrophilic–lipophilic balance index demonstrated the wetting capacity of the biosurfactant and its tendency to form oil-in-water (O/W) emulsions, with 50.0 ± 0.20% foaming capacity. The biosurfactant did not exhibit cytotoxicity in the MTT assay or irritant potential. Additionally, an antioxidant activity of 58.25 ± 0.32% was observed at a concentration of 40 mg/mL. The compound also exhibited antimicrobial activity against various pathogenic microorganisms. The characterisation of the biosurfactant using magnetic nuclear resonance and Fourier transform infrared spectroscopy revealed that the biomolecule is a glycolipid with an anionic nature. The results demonstrate that biosurfactant produced in this work has potential as an active biotechnological ingredient for innovative, eco-friendly cosmetic formulations. Full article

Hydrogels are widely known for their ability to increase soil water retention and for their potential slow nutrient release mechanism. They have been constantly improved to meet the growing demand for sustainability in agriculture. Research focused on the development of biodegradable hydrogels, produced from industrial cellulose waste, are an ecological and efficient alternative soil ameliorant for the improvement of agricultural land. The objective of this study was to evaluate the impacts of two types of hydrogel (processed in a glass reactor versus a twin-screw extruder) on soils with different textures (clay and sandy loam), testing their water retention capacity, nitrogen leaching, and effects on seed germination. The methodology included the evaluation of water retention capacity at different pressures with different hydrogel addition rates in the soil, leaching tests in columns filled with soil and hydrogel layers, and germination tests of sorghum and corn. The results indicated that the addition of hydrogel significantly improved water retention, especially in sandy loam soils. The hydrogels also reduced nitrogen leaching, acting as nitrification inhibitors and limiting the conversion of ammonium to nitrate, with greater effectiveness in clayey soils. In the tested formulations, it was observed that the hydrogel doses applied to the columns favored nitrogen retention in the region close to the roots, directly influencing the initial stages of germination. This behavior highlights the potential of hydrogels as tools for directing nutrients in the soil profile, indicating that adjustments to the C:N ratio, nutrient release rate, and applied doses can optimize their application for different crops. Full article

Burn injuries are complex and require effective wound management strategies. Traditional treatments, such as dermal templates, are limited by simplified extracellular matrix (ECM) composition (e.g., collagen-elastin or collagen-glycosaminoglycan), sheet-based formats, and frequent use of animal-derived materials. These limitations can reduce wound conformity, biocompatibility, and integration with host tissue. Functional hydrogels are being explored as alternatives due to properties such as high water content, biodegradability, adhesiveness, antimicrobial activity, and support for angiogenesis. Unlike standard templates, hydrogels can adapt to irregular wound shapes as in burn wounds and reach deeper tissue layers, supporting moisture retention, cell migration, and controlled drug delivery. These features may improve the wound environment and support healing in burns of varying severity. This review outlines recent developments in functional hydrogel technologies and compares them to current clinical treatments for burn care. Emphasis is placed on the structural and biological features that influence performance, including material composition, bioactivity, and integration capacity. Through an exploration of key mechanisms of action and clinical applications, this review highlights the benefits and challenges associated with hydrogel technology, providing insights into its future role in burn care. Full article

Keratin, a fibrous structural protein, has been employed as a biomaterial for hemostasis and tissue repair due to its structural stability, mechanical strength, biocompatibility, and biodegradability. While extensive research has focused on developing scaffolds using keratin extracted from various sources, no studies to date have explored the use of keratin derived from human nail clippings. In this study, keratin was extracted from human nail clippings using the Shindai method and used to fabricate and compare two types of scaffolds for bone tissue engineering via the freeze-drying method. The first scaffold consisted of keratin combined with gelatin (KG), while the second combined keratin, gelatin, and hydroxyapatite (HAp) (KGH), the latter synthesized from blood cockle clam shells using the wet precipitation method. Physicochemical characterization and surface morphology analysis of keratin and both scaffolds showed promising results. Tensile strength testing revealed a significant difference in Young’s modulus. The KG scaffold exhibited higher porosity, water uptake, and water retention capacity compared to the KGH scaffold. In vitro biocompatibility studies revealed that the KGH scaffold supported higher cell proliferation compared to the KG scaffold. This study demonstrates the potential of using human nail-derived keratin in composite scaffold fabrication and serves as a foundation for future research on this novel biomaterial source. Full article

This study theoretically investigates the potential of a polyacrylamide copolymerized with amylose, a primary component of starch, to evaluate its efficiency in removing heavy metals from industrial wastewater. This material concept seeks to combine the high adsorption capacity of polyacrylamide with the low cost and biodegradability of starch, ultimately aiming to offer an economical, efficient, and sustainable alternative for wastewater treatment. To this end, a computational model based on density functional theory (DFT) was developed, utilizing the B3LYP functional with the 6-311++G(d,p) basis set, a widely recognized combination that strikes a balance between accuracy and computational cost. The interactions between an acrylamide-amylose (AM/Amy) polymer matrix, as well as the individual polymers (AM and Amy), and the metal ions Pb, Hg, and Cd in their hexahydrated form (M·6H₂O) were analyzed. This modeling approach, where M represents any of these metals, simulates a realistic aqueous environment around the metal ion. Molecular geometries were optimized, and key parameters such as total energy, dipole moment, frontier molecular orbital (HOMO-LUMO) energy levels, and Density of States (DOS) graphs were calculated to characterize the stability and electronic reactivity of the molecules. The results indicate that this proposed copolymer, through its favorable electronic properties, exhibits a high adsorption capacity for metal ions such as Pb and Cd, positioning it as a promising material for environmental applications. Full article