Search Results (101)

The olive oil sector constitutes a fundamental pillar in the Mediterranean region from socio-economic and cultural perspectives. Nonetheless, it produces significant amounts of waste, leading to numerous environmental issues. These waste streams contain valuable compounds that can be recovered and utilized as inputs for various applications. This study introduces a novel value chain for olive wastes, focused on extracting lignin from olive pomace by ionic liquids and polyphenols from olive mill wastewater, which are then incorporated as hybrid nanoparticles in the formulation of an innovative starch-based biofertilizer. This biofertilizer, obtained by using residual wastewater as a source of soluble nitrogen, acting at the same time as a plasticizer for the biopolymer, was demonstrated to surpass traditional NPK biofertilizers’ efficiency, allowing for root growth and foliage in drought conditions. In order to recognize the environmental impact due to its production and align it with the technical output, the circularity and environmental performance of the proposed system were innovatively evaluated through a combination of Life Cycle Assessment (LCA) and the Material Circularity Indicator (MCI). LCA results indicated that the initial upcycling process was potentially characterized by significant hot spots, primarily related to energy consumption (>0.70 kWh/kg of water) during the early processing stages. As a result, the LCA score of this preliminary version of the biofertilizer may be higher than that of conventional commercial products, due to reliance on thermal processes for water removal and the substantial contribution (56%) of lignin/polyphenol precursors to the total LCA score. Replacing energy-intensive thermal treatments with more efficient alternatives represents a critical area for improvement. The MCI value of 0.84 indicates limited potential for further enhancement. Full article

This study aimed to evaluate the antibacterial activity of several technical lignins against major environmental bacteria that cause mastitis in dairy cattle. The efficacy of four types of technical lignins against environmental mastitis pathogens was evaluated using MIC and MBC assays. The best candidate, sodium lignosulfonate (NaL-O), was further tested using sawdust bedding substrates. Substrates were prepared in different cleanliness conditions: sawdust only, sawdust plus urine, sawdust plus feces, or sawdust plus a combination of both. The antimicrobial activity of NaL-O against the mixture of environmental mastitis-causing pathogens was determined on days 0, 2, and 6 of incubation. In addition, the components of bedding substrates were analyzed to help understand the dynamics of pathogen loads. In the MIC and MBC assays, NaL-O showed the best antimicrobial performance against all pathogens except Escherichia coli. When testing in the bedding substrates, the addition of NaL-O decreased the concentration of Staphylococcus chromogenes, Streptococcus uberis, and Pseudomonas aeruginosa across all bedding cleanliness levels at d 0, 2, and 6 of incubation. As the incubation time increased, the antimicrobial effect decreased. NaL-O also lowered the counts of E. coli and Klebsiella pneumoniae across all incubation times, but to a lesser extent. The presence of feces significantly reduced the antibacterial effects of NaL-O for these two bacteria. Among the technical lignins tested, NaL-O showed the broadest antibacterial activity against the mastitis pathogens tested. This study suggests that NaL-O has promising potential as a bedding conditioner to control environmental pathogens on dairies due to its low cost, ready availability, and compatibility with sustainable livestock practices. Combined with bedding cleanliness, bedding conditioner application may play a crucial role in reducing the growth of EM pathogens and subsequent mastitis incidence. Full article

This study presents the development and characterization of sustainable bio-bricks incorporating agricultural residues—specifically coffee husks and bovine excreta—as partial substitutes for cement. A mixture design optimized through response surface methodology (RSM) identified the best-performing formulation, namely 960 g of cement, 225 g of lignin (extracted from coffee husks), and 315 g of bovine excreta. Experimental evaluations included compressive and flexural strength, water absorption, density, thermal conductivity, transmittance, admittance, and acoustic transmission loss. The optimal mixture achieved a compressive strength of 1.70 MPa and a flexural strength of 0.56 MPa, meeting Colombian technical standards for non-structural masonry. Its thermal conductivity (~0.19 W/(m×K)) and transmittance (~0.20 W/(m²×K)) suggest good insulation performance. Field tests in three Colombian climate zones confirmed improved thermal comfort compared to traditional clay brick walls, with up to 8 °C internal temperature reduction. Acoustic analysis revealed higher sound attenuation in bio-bricks, especially at low frequencies. Chemical and morphological analyses (SEM-EDS, FTIR, and TGA) confirmed favorable thermal stability and the synergistic interaction of organic and inorganic components. The findings support bio-bricks’ potential as eco-efficient, low-carbon alternatives for sustainable building applications. Full article

Wood adhesives play a critical role in the wood processing industry; however, traditional formaldehyde-based adhesives pose health risks and are reliant on non-renewable resources. This study aims to develop a bio-based wood adhesive with excellent water resistance, focusing on environmentally friendly solutions. The synthesis of an oxidized starch-lignin (OSTL) composite adhesive was accomplished by modifying starch via oxidation and subsequent cross-linking with lignin. Ammonium persulfate (APS) was employed for oxidation of starch, introducing aldehyde groups that upgrade its reactivity with lignin. Subsequently, the oxidized starch (OST) was cross-linked with the phenolic rings of lignin, resulting in a strong network structure. The oxidation of starch and its cross-linking mechanism with lignin were investigated using the Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR), and X-ray photoelectron spectroscopy (XPS) techniques, proving the formation of aldehyde and carboxyl groups with subsequent reaction possibilities. The effects of oxidant dosage, oxidation time, and the ratio of starch to lignin on the adhesive properties were systematically studied. The results demonstrated that the OSTL adhesive, prepared under optimized conditions, exhibited outstanding adhesion strength (1.23 MPa in dry state) and water resistance (0.94 MPa after 24 h cold water immersion, 1.04 MPa after 3 h in hot water, and 0.69 MPa after 3 h in boiling water), significantly outperforming conventional wood adhesives in terms of cold water, hot water, and boiling water resistance. In addition, the thermal behavior of the OSTL adhesive was further validated using differential scanning calorimetry (DSC) as well as thermogravimetric analysis (TGA). This study presents new insights and technical support for the development of green, environmentally friendly, and highly water-resistant lignin-based bio-adhesives. Full article

Excessive nitrogen fertilizer use has resulted in growing nitrate contamination of groundwater. In this study, an in situ bioelectrochemical reactor (isBER) reinforced with woodchips was developed for the treatment of actual nitrate-contaminated groundwater. During the 75-day experiment, the denitrification performance, grid permeability, and microbial community structure were investigated under different flow rates and current densities. The reactor achieved a remarkable nitrate removal efficiency of 97.6% ± 0.4% and a rate of 2.09 ± 0.14 mg-N/(L·h). These results were obtained at a temperature of 18.5 ± 0.8 °C, a current density of 350 mA/m², and a flow rate of 10 cm/d. Notably, the reactor can adapt to a wide flow-rate range of 5~20 cm/d and the operation proceeded smoothly without any blockages. Furthermore, the cathode module demonstrated enrichment of hydrogen autotrophic denitrifying bacteria (Pseudomonas, Stenotrophomonas) and heterotrophic denitrifying bacteria (Brucella, Enterobacteriaceae). Conversely, the anode module exhibited relatively high enrichment levels of aerobic microorganisms and lignin-degrading bacteria (Cellvibrio). The research results can provide novel insights and technical support for in situ remediation of groundwater nitrate contamination. Full article

Single-ring aromatic compounds including BTX (benzene, toluene, xylene) serve as essential building blocks for high-performance fuels and specialty chemicals, with extensive applications spanning polymer synthesis, pharmaceutical manufacturing, and aviation fuel formulation. Current industrial production predominantly relies on non-renewable petrochemical feedstocks, posing the dual challenges of resource depletion and environmental sustainability. The catalytic hydrodeoxygenation (HDO) of lignin-derived phenolic substrates emerges as a technologically viable pathway for sustainable aromatic hydrocarbon synthesis, offering critical opportunities for lignin valorization and biorefinery advancement. This article reviews the relevant research on the conversion of lignin-derived phenolic compounds’ HDO to benzene and aromatic hydrocarbons, systematically categorizing and summarizing the different types of catalysts and their reaction mechanisms. Furthermore, we propose a strategic framework addressing current technical bottlenecks, highlighting the necessity for the synergistic development of robust heterogeneous catalysts with tailored active sites and energy-efficient process engineering to achieve scalable biomass conversion systems. Full article

Biomass is an energy source with variable physico-chemical properties. Thermal treatments lower moisture and volatile matter contents. They also raise the high heating value (HHV). This is especially desirable for agro-wastes with low-energy potential, like maize cobs. To make pellets from biomass, it is important to keep the lignin intact. It is responsible for particle adhesion. This paper presents a study focused on high-temperature drying of maize cobs. The process temperatures were selected from a range between 60 and 220 °C. The upper temperature limit prevents significant lignin breakdown. We also do not exceed the self-ignition temperature of the raw material. The study analyzed changes in basic technical parameters. These include moisture content, ash content, volatile matter, and HHV. We tested the grinding and densification process. We measured the raw material’s particle size distribution (PSD), specific density, and the mechanical durability (DU) of the agglomerates. The study showed a positive effect of high-temperature drying on the technical parameters. We found that the drying of corn cobs at a temperature of 180 °C gives the best results. Both PSD and DU values indicate that it is possible to create quality compacted biofuels from this material. Full article

Biopolymers are revolutionizing the materials landscape, driven by a growing demand for sustainable alternatives to traditional petroleum-based materials. Sourced from biological origins, these polymers are not only environment friendly but also present exciting solutions in healthcare, packaging, biosensors, high performance, and durable materials as alternatives to crude oil-based products. Recently, biopolymers derived from plants, such as lignin and cellulose, alongside those produced by bacteria, like polyhydroxyalkanoates (PHAs), have captured the spotlight, drawing significant interest for their industrial and eco-friendly applications. The growing interest in biopolymers stems from their potential as sustainable, renewable materials across diverse applications. This review provides an in-depth analysis of the current advancements in plant-based and bacterial biopolymers, covering aspects of bioproduction, downstream processing, and their integration into high-performance next-generation materials. Additionally, we delve into the technical challenges of cost-effectiveness, processing, and scalability, which are critical barriers to widespread adoption. By highlighting these issues, this review aims to equip researchers in the bio-based domain with a comprehensive understanding of how plant-based and bacterial biopolymers can serve as viable alternatives to petroleum-derived materials. Ultimately, we envision a transformative shift from a linear, fossil fuel-based economy to a circular, bio-based economy, fostering more sustainable and environmentally conscious material solutions using novel biopolymers aligning with the framework of the United Nations Sustainable Development Goals (SDGs), including clean water and sanitation (SDG 6), industry, innovation, and infrastructure (SDG 9), affordable and clean energy (SDG 7), sustainable cities and communities (SDG 11), responsible production and consumption (SDG 12), and climate action (SDG 13). Full article

In the present work, the application of lignin (LIG) as a bioactive additive for the preparation of drug-loaded tablets by direct compression has been studied, and its influence on the release of chlorzoxazone (CLZ) from the hydrophilic matrices has been followed. In hydrophilic matrices, the excipients Kollidon^® SR (KOL) and chitosan (CHT) have been used in various amounts and tested in the preparation of 500 mg tablets. They were used as matrix-forming agents, and their influence on the flow and the compressibility properties as well as their effect on the pharmaco-chemical characteristics of the matrix tablets have been studied. Based on the initial evaluation of the pharmaco-technical analysis, pharmaco-chemical characteristics, and in vitro release profile, three matrix tablet formulations (FLa, FLb, and FLc) were selected and further tested. They were evaluated through Fourier-transform infrared spectrometry (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimetry (DSC), and in vitro dissolution tests. The three formulations were comparatively studied regarding the release kinetics of active substances using in vitro release testing. The in vitro kinetic study reveals a complex release mechanism occurring in two steps of drug release. The first one is a burst effect that occurs within the first 0–2 h, involving a rapid release of the majority of the drug in a short time, followed by the second step as a prolonged release of the drug, which is relatively constant with a fixed rate over the next 2–36 h. Two factors have been calculated to assess the release profile of chlorzoxazone: f1—the similarity factor and f2—the difference factor together with the correlation coefficient R². Comparing their values, the three optimal formulations have been selected, containing 55 mg LIG (FLa), 60 mg LIG (FLb), or 65 mg LIG (FLc), confirming that LIG next to KOL and CHT influenced the release characteristics of the matrix tablets. Due to the presence of lignin in the matrix of the three formulations, FLa, FLb, and FLc tablets with CLZ, the antioxidant activity has improved. The antioxidant activity of FLc was found to be 21.36% ± 1.06 greater than that of FLa and FLb. The tablets FLa, FLb, and FLc also presented higher antimicrobial activity against Staphylococcus aureus, Escherichia coli, Candida albicans, and colistin-resistant Klebsiella spp. The higher the concentration of LIG in the matrix (FLc), the higher the antimicrobial activity. By using LIG, the drug dose could be decreased. It can be concluded that lignin can be used as a multifunctional pharmaceutical bioactive additive/excipient for tablets. Its interesting properties have been proven, and its use as a pharmaceutical active additive should be exploited for different applications. Full article

This study aims to explore the feasibility of producing submicrometer and nanometer cellulose fibers derived from rice husk treated with a novel method which selectively eliminate hemicellulose and lignin, while maintaining the integrity of the cellulosic and silica constituents. Three distinct processing methods are tested to extract the nanocellulose, namely hand milling, ball milling, and wet milling using a high-shear wet media mill from Masuko Sangyo Co., Ltd., Kawaguchi-city, Japan. A range of analytical methods, including Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA), are utilized to characterize the morphology, elemental composition, thermal stability, and chemical properties of the samples. The study revealed that among the tested methods, only wet milling successfully produced cellulose nanofibrils and silica nanoparticles, forming a biogenic organic–inorganic nanohybrid system. The nanofibers had lengths in the range of 120 nm and below, while the nanoparticles were in the tens of nanometers. The silica nanoparticles were found to adhere to the cellulose nanofibrils, forming a biogenic organic–inorganic nanohybrid system, with potential applications across diverse fields, including biomedical (drug delivery, biosensing, bone regeneration, and wound healing), cosmetic (skin and dental care), technical (insulating aerogels, flame retardants, and UV-absorbing pigments), and food applications (dietary supplements, thickeners). Full article

Green materials are emerging as sustainable alternatives in water and wastewater treatment. Due to their biodegradability, renewable origin and low toxicity characteristics, green materials are an alternative to conventional synthetic materials. Green materials include nanomaterials of natural origin, biopolymers and composites that optimize the adsorption and removal of contaminants. The applications of cellulose nanofibers, alginates, chitosan and lignin stand out, as well as functionalized hydrogels and aerogels for the removal of heavy metals, dyes and organic contaminants. The analysis of the mechanisms and processes of contaminant removal and modeling and optimization techniques are included as key emerging tools for the design and optimization of these materials, allowing one to predict properties, simulate interactions and customize solutions. Despite the sustainability benefits of green materials, they face technical and economic challenges, such as scalability, synthesis costs and experimental validation. This work concluded that green materials, combined with modeling and optimization tools, are essential to move towards more sustainable, efficient and environmentally friendly water treatment technologies, aligned with global objectives of sustainable development and climate change mitigation. Full article

The potential of technical lignins as secondary raw materials is discussed. The characteristics of lignin pyrolysis, with particular emphasis on slow pyrolysis technologies, are briefly summarized. The slow pyrolysis process, which can be self-sustained by burning the coproduced gas, can primarily produce high-quality biochar in significant amounts, to be used as a fuel, as a reductant in metallurgy, and as an adsorbent and catalyst component. Together, significant amounts of bio-oil can be produced, rich in guaiacols, which are commercial and expensive chemicals produced today via petrochemical routes and used in pharmacology, food chemistry, polymer chemistry, etc. Such compounds, or bio-oil itself, can also be converted by hydrodeoxygenation into biofuels. A possible simplified flowsheet for a lignin slow pyrolysis process in the frame of a ligneocellulosics-based biorefinery is proposed. Full article

Conventional hydrogen production processes, which often involve fossil raw materials, emit significant amounts of carbon dioxide into the atmosphere. This study critically evaluates the feasibility of using sugarcane biomass as an energy source to produce green hydrogen. In the 2023/2024 harvest, Brazil, the world’s largest sugarcane producer, processed approximately 713.2 million metric tons of sugarcane. This yielded 45.68 million metric tons of sugar and 29.69 billion liters of first-generation ethanol, equivalent to approximately 0.0416 liters of ethanol per kilogram of sugarcane. A systematic literature review was conducted using Scopus and Clarivate Analytics Web of Science, resulting in the assessment of 335 articles. The study has identified seven potential biohydrogen production methods, including two direct approaches from second-generation ethanol and five from integrated bioenergy systems. Experimental data indicate that second-generation ethanol can yield 594 MJ per metric ton of biomass, with additional energy recovery from lignin combustion (1705 MJ per metric ton). Moreover, advances in electrocatalytic reforming and plasma-driven hydrogen production have demonstrated high conversion efficiencies, addressing key technical barriers. The results highlight Brazil’s strategic potential to integrate biohydrogen production within its existing bioenergy infrastructure. By leveraging sugarcane biomass for green hydrogen, the country can contribute significantly to the global transition to sustainable energy while enhancing its energy security. Full article

The growing interest in renewable and natural antioxidants has positioned lignin as one of the most significant bioresources for sustainable applications. Lignin, a polyphenolic biomolecule and a major by-product of chemical pulping and biorefinery processes, is abundant and widely accessible. Recent advancements in lignin modification, fractionation, and innovative biorefinery techniques have expanded its potential applications, particularly as a natural antioxidant. This review explores the underlying chemistry of lignin’s antioxidant activities, from model compounds to technical lignin resources, and examines its current applications. Additionally, we highlight the influence of lignin’s chemical structure and functional groups on its antioxidant efficacy, emphasizing its promising role in the development of practical and sustainable solutions. Full article

In line with environmental awareness movements and social concerns, the textile industry is prioritizing sustainability in its strategic planning, product decisions, and brand initiatives. The use of non-biodegradable materials, obtained from non-renewable sources, contributes heavily to environmental pollution throughout the textile production chain. As sustainable alternatives, considerable efforts are being made to incorporate biodegradable biopolymers derived from residual biomass, with reasonable production costs, to replace or reduce the use of synthetic petrochemical-based polymers. However, the commercial deployment of these biopolymers is dependent on high biomass availability and a cost-effective supply. Residual forest biomass, with lignocellulosic composition and seasonably available at low cost, constitutes an attractive renewable resource that might be used as raw material. Thus, this review aims at carrying out a comprehensive analysis of the existing literature on the use of residual forest biomass as a source of new biomaterials for the textile industry, identifying current gaps or problems. Three specific biopolymers are considered: lignin that is recovered from forest biomass, and the bacterial biopolymers poly(hydroxyalkanoates) (PHAs) and bacterial cellulose (BC), which can be produced from sugar-rich hydrolysates derived from the polysaccharide fractions of forest biomass. Lignin, PHA, and BC can find use in textile applications, for example, to develop fibers or technical textiles, thus replacing the currently used synthetic materials. This approach will considerably contribute to improving the sustainability of the textile industry by reducing the amount of non-biodegradable materials upon disposal of textiles, reducing their environmental impact. Moreover, the integration of residual forest biomass as renewable raw material to produce advanced biomaterials for the textile industry is consistent with the principles of the circular economy and the bioeconomy and offers potential for the development of innovative materials for this industry. Full article