Search Results (1,279)

This study developed a two-step conversion strategy for the efficient conversion of bamboo waste into 5-hydroxymethylfurfural (HMF). First, ultrasonic-assisted formic acid pretreatment was used at 80 °C for 3 h, removing approximately 83.7% of hemicellulose and 76.5% of lignin from the biomass, with a cellulose recovery of 93.5%. The ultrasonic step significantly enhanced the chemical action of formic acid through cavitation, allowing formic acid to penetrate deeper into the biomass, thereby more effectively removing hemicellulose and lignin. Subsequently, glucose was obtained through an enzymatic hydrolysis. In the second step of HMF preparation, citric acid in the hydrolysate was combined with ChCl to form an acidic deep eutectic solvent (DES), and metal chlorides were added as Lewis acid catalysts. Experiments results showed that when the ChCl–citric acid ratio was 2:1, and the Ca²⁺ concentration was 100 mM, an HMF yield of 51.9% was obtained at 220 °C for 1.5 h. This study provides an efficient, mild, and environmentally friendly method for the high-value valorization of waste bamboo. Full article

Driven by the energy transition within the framework of the United Nations Framework Convention on Climate Change, second-generation (2G) ethanol stands out as a technical and sustainable alternative to fossil fuels. Although first-generation ethanol, produced from saccharine and starchy feedstocks, represents an advance in mitigating emissions, its expansion is limited by competition with areas destined for food production. In this context, 2G ethanol, obtained from residual lignocellulosic biomass, emerges as a strategic route for diversifying and expanding the renewable energy matrix. Thus, this work discusses the current state of 2G ethanol technology based on the gradual growth in production and the consolidation of this route over the last few years. Industrial second-generation ethanol plants operating around the world demonstrate the high potential of agricultural waste as a raw material, particularly corn straw in the United States, which offers a lower cost and significant yield in the production of this biofuel. Similarly, in Brazil, sugarcane by-products, especially bagasse and straw, are consolidating as the main sources for 2G ethanol, integrated into the biorefinery concept and the valorization of by-products obtained during the 2G ethanol production process. However, despite the wide availability of lignocellulosic biomass and its high productive potential, the consolidation of 2G ethanol is still conditioned by technical and economic challenges, especially the high costs associated with pretreatment stages and enzymatic cocktails, as well as the formation of inhibitory compounds that compromise the efficiency of the process. Genetic engineering plays a particularly important role in the development of microorganisms to produce more efficient enzymatic cocktails and to ferment hexoses and pentoses (C₆ and C₅ sugars) into ethanol. In this scenario, not only are technological limitations important but also public policies and tax incentives, combined with the integration of the biorefinery concept and the valorization of (by)products, which prove fundamental to reducing costs, increasing process efficiency, and ensuring the economic viability and sustainability of second-generation ethanol. Full article

The massive influx of pelagic Sargassum in the Caribbean poses a serious environmental, social, and economic problem, as the stranded biomass is often treated as waste and deposited in landfills. This literature review synthesizes recent research highlighting its potential for valorization in various industries, turning this challenge into an opportunity. Sargassum has low levels of protein and lipids. Still, it is particularly rich in carbohydrates, such as alginates, fucoidans, mannitol, and cellulose, as well as secondary metabolites, including phenolic compounds, flavonoids, pigments, and phytosterols with antioxidant and bioactive properties. These biochemical characteristics allow for its application in renewable energy (bioethanol, biogas, biodiesel, and combustion), agriculture (fertilizers and biostimulants), construction (composite materials, cement additives, and insulation), bioremediation (adsorption of heavy metals and dyes), and in the health sector (antioxidants, anti-inflammatories, and pharmacological uses). A major limitation is its high bioaccumulation capacity for heavy metals, particularly arsenic, which increases environmental and health risks and limits its direct use in food and feed. Therefore, innovative pretreatment and bioprocessing are essential to mitigate these risks. The most promising approach for its utilization is a biorefinery model, which allows for the sequential extraction of multiple high-value compounds and energy products to maximize benefits, reduce costs, and sustainably transform Sargassum from a coastal pest into a valuable industrial resource. Full article

Microplastic quantification in marine vegetated ecosystems remains analytically demanding, yet little is known about the environmental footprint of the laboratory procedures required to isolate and measure these particles. This study applies Life Cycle Assessment (LCA) to laboratory analytical workflows for microplastics quantification, focusing exclusively on sample preparation and analytical procedures rather than natural environmental absorption or fate processes, in two ecologically relevant matrices: (i) pelagic algae (Sargassum) and (ii) seagrass biomass. Using the openLCA 2.5 and the ReCiPe Midpoint (H) v1.13 methods, the analysis integrates foreground inventories of digestion, filtration, drying, and spectroscopic identification, combined with background datasets from OzLCI2019, ELCD 3.2 and USDA. Results show substantially higher impacts for the algae scenario, particularly for climate change, human toxicity, ionising radiation and particulate matter formation, largely driven by longer digestion times, increased reagent use and higher energy demand during sample pre-treatment. Conversely, the seagrass scenario exhibited lower burdens per functional unit due to reduced organic complexity and shorter laboratory processing requirements. These findings highlight the importance of matrix-specific methodological choices and the influence of background datasets on impact profiles. This study provides the first benchmark for the environmental performance of microplastic analytical workflows and underscores the need for harmonised, low-impact laboratory protocols to support sustainable monitoring of microplastic pollution in marine ecosystems. Full article

Fruit shrubs’ lignocellulosic biomass remaining as waste after harvesting and/or after pruning is an underutilized, little-explored bioresource. Sea buckthorn (Hippophae rhamnoides L.), aronia (Aronia melanocarpa) and blackcurrant (Ribes nigrum) berries are rich in biologically active compounds, so these shrubs’ woody biomass derivatives are prospective investigation objects. The influence of pre-treated biomass, extracts, and purified proanthocyanidins on the oxidative stability of lipid-based systems was studied by accelerated oxidation method. Emulsion stability, antimicrobial activity against bacteria that causes acne—Cutibacterium acnes; contaminating wounds; skin care products—Streptococcus pyogenes, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus; cytotoxicity and phototoxicity of extracts and proanthocyanidins on HaCaT human keratinocytes were tested. The study established that biomass, lipophilic extracts obtained using liquefied hydrofluorocarbon, and hydrophilic extracts obtained by aqueous ethanol increased oxidative stability of lipid-based formulations. Compounds with skin-protecting properties were detected. Sea buckthorn and aronia hydrophilic extracts and proanthocyanidins had the highest antimicrobial activity. Low phototoxicity was revealed, emphasizing safety and applicability in topical formulations; human HaCaT keratinocyte viability was the best with aronia extracts, but none of the other samples decreased cell viability by more than 50%. It was proven that agro-waste biomass is a prospective source of multifunctional ingredients for cosmetic and pharmaceutical topical formulations. Full article

Cheese whey, the major by-product of the dairy industry, poses an environmental challenge due to its high organic load but simultaneously represents a nutrient-dense matrix suitable for biotechnological valorization. This review synthesizes recent advances positioning whey as (i) a fermentation substrate for lactic acid bacteria, yeasts/fungi, and microalgae, enabling the production of functional biomass, organic acids, bioethanol, exopolysaccharides, enzymes, and wastewater bioremediation; (ii) a platform for postbiotic generation, supporting cell-free preparations with functional activities; and (iii) a food-grade encapsulating material, particularly through whey proteins (β-lactoglobulin, α-lactalbumin), which can form emulsions, gels, and films that protect biotics and bioactive compounds during processing, storage, and gastrointestinal transit. We analyze key operational variables (whey type and pretreatment, supplementation strategies, batch and continuous cultivation modes), encapsulation routes (spray drying, freeze-drying, and hybrid protein–polysaccharide systems), and performance trade-offs relevant to industrial scale-up. Finally, we outline future directions, including precision fermentation, mixed-culture processes with in situ lactase activity, microfluidics-enabled encapsulation, and life-cycle assessment, to integrate product yields with environmental performance. Collectively, these strategies reframe whey from a high-impact waste into a circular bioeconomy resource for the food, nutraceutical, and environmental sectors. Full article

Alkaline pretreatment of wheat straw could significantly augment enzymatic hydrolysis for producing fermentable sugars, which is a pivotal process for the conversion of lignocellulosic biomass into advanced biofuels, biomaterials, or biochemicals. Yet, the enzymatic conversion process system is complex and multivariate, and study on the interaction mechanism of the key parameters in enzymatic hydrolysis is still lacking. Therefore, in this work, multivariate data analysis (MDA) (i.e., principal component analysis (PCA) and partial least square (PLS)) was conducted to reveal the inherent relationship and the significance of these factors in a modified alkali pretreatment system. A robust model, developed from 140 enzymatic hydrolysis datasets, was validated with an additional 20 datasets, demonstrating the predictive prowess of the PLS model. MDA identified that cellulase dosage, mechanical refining, dye adsorption value, and solid content were paramount variables. The integration of cellulase and xylanase notably elevated sugar yields and the conversion rates of carbohydrates, surpassing those of single enzyme treatments. The model’s predictive accuracy, reflected in the close alignment between observed and predicted data, underscores its suitability for optimizing and controlling the enzymatic hydrolysis process. This study paves a way for data-driven strategies to enhance industrial bioprocessing of lignocellulosic feedstocks. Full article

The global floriculture industry generates massive organic residues that pose environmental risks but offer untapped bioenergy potential. This review evaluates the feasibility of valorizing flower waste through anaerobic digestion (AD) by synthesizing experimental data on substrate characterization, pretreatment efficacy, and reactor performance. Results indicate that biochemical methane potentials (BMP) vary significantly, ranging from 89 to 412 mL_CH4·g⁻¹_VS, depending on plant species and tissue composition. Major bottlenecks include high lignocellulosic recalcitrance (lignin content up to 0.28 g·g⁻¹_TS) and the presence of inhibitory phenolic compounds. Analysis reveals that while alkaline pretreatments effectively disrupt lignocellulosic structures, co-digestion strategies are essential to mitigate inhibition and balance nutrient ratios. However, current research is predominantly limited to laboratory-scale batch assays, leaving a critical knowledge gap regarding long-term process stability and inhibition dynamics in continuous systems. To transform this laboratory concept into a scalable technology, future efforts must focus on pilot-scale continuous reactor trials, standardized testing protocols, and comprehensive techno-economic and life cycle assessments. Full article

Agricultural biomass has potential as a renewable and versatile carbon feedstock for developing eco-friendly and biodegradable polymers capable of replacing conventional petrochemical plastics. To address the growing environmental concerns associated with plastic waste and carbon emissions, lignocellulosic residues, edible crop by-products, and algal biomass were utilized as sustainable raw materials. These biomasses provided carbohydrate-, lipid-, and lignin-rich fractions that were deconstructed through optimised physical, chemical, and enzymatic pretreatments to yield fermentable intermediates, such as reducing sugars, organic acids, and fatty acids. The intermediates were subsequently converted through tailored microbial fermentation processes into biopolymer precursors, primarily polyhydroxyalkanoates (PHAs) and lactate-based monomers. The resulting monomers underwent polymerization via polycondensation and ring-opening reactions to produce high-performance biodegradable plastics with tunable structural and mechanical properties. Additionally, the direct extraction and modification of naturally occurring polymers, such as starch, cellulose, and lignin, were explored to develop blended and functionalized bioplastic formulations. Comparative evaluation revealed that these biomass-derived polymers possess favourable physical strength, thermal stability, and biodegradability under composting conditions. Life-cycle evaluation further indicated a significant reduction in greenhouse gas emissions and improved carbon recycling compared to fossil-derived counterparts. The study demonstrates that integrating agricultural residues into bioplastic production not only enhances waste valorization and rural bioeconomy but also supports sustainable material innovation for packaging, farming, and consumer goods industries. These findings position agriculture-based biodegradable polymers as a critical component of circular bioeconomy strategies, contributing to reduced plastic pollution and improved environmental sustainability. Full article

This study addresses the lack of transparent methods for calculating the energy requirements of pulsed electric field (PEF) pretreatments in biogas research. Two detailed approaches are proposed and evaluated to quantify the energy consumed during the pretreatment of lignocellulosic harvest residues (corn, soybean, and sunflower) using a low-frequency electric field. The first approach is based on previously measured capacitor parameters, including resistance (R_s, R_p), inductance (L_s), capacitance (C_p), and loss factor (D), which were interpolated to 50 Hz from measurements performed over the frequency range of 100 Hz to 10 kHz. The second approach relies on direct measurements of the effective voltage and current waveforms across the capacitor, followed by calculation of the power factor (cos φ). Both methods enable reliable estimation of energy consumption and differ primarily in the type of input data required: Method 1 is based on capacitor characteristics determined before and after pretreatment, while Method 2 uses real-time treatment data. Despite these differences, the two approaches yielded highly consistent results, confirming their robustness and applicability. The calculated energy values were subsequently incorporated into a net energy balance by comparing the energy consumed during pretreatment with the methane energy output from anaerobic digestion. For all three investigated lignocellulosic substrates, PEF pretreatment resulted in a positive energy balance under the applied process conditions. Full article

Environmental pollution caused by industrialization and population growth has intensified the demand for sustainable materials capable of mitigating contaminants effectively. In this context, the green synthesis of carbon-based nanomaterials derived from biomass has gained significant attention as an eco-friendly and renewable approach that reduces dependence on fossil resources. These nanomaterials exhibit outstanding physicochemical characteristics, including high surface area, tunable porosity, abundant functional groups, and excellent stability, which enhance their performance in environmental remediation. Specifically, biomass-derived carbon nanomaterials have demonstrated remarkable efficiency as adsorbents for the removal of heavy metals and organic pollutants, as well as photocatalysts for the degradation of toxic compounds under visible light irradiation. The physicochemical properties of the resulting materials are strongly influenced by the type and pretreatment of the biomass, along with synthesis parameters such as pyrolysis temperature, activation process, and heteroatom doping. This review highlights recent advances in the synthesis, characterization, and environmental applications of biomass-derived carbon nanomaterials, emphasizing their potential as cost-effective, scalable, and sustainable solutions for wastewater treatment and pollutant degradation in both aquatic and atmospheric systems. Full article

Heavy metals release in the environment represents a growing threat to human health and nature, particularly due to industrial activities contributing to soil and water contamination. In this study, Ganoderma lucidum heteropolysaccharides (GLHP) were evaluated as a biosorbent for cadmium removal. The biomass was acquired following the production of Ganoderma lucidum fruiting bodies and consisted of remnants from the fungus and cultivation substrate. Cd(II) and elemental analysis were carried out by atomic adsorption spectrometry (AAS) and inductively coupled plasma mass spectroscopy (ICP-MS), respectively. The biosorption efficiency was critically evaluated, optimizing physical adsorption parameters for batch, column, and percolation configuration, as well as application in real environmental water. Utilizing a simple pre-rinsing step, completely omitting any chemical pretreatment, the Cd(II) removal efficiency was improved from 41.2% to 78.4% in a batch system and up to 98.4% in a fixed-bed column, making it suitable not only for wastewater treatment but also for drinking water purification. The adsorption kinetics were described by a pseudo-second-order (PSO) model and further analyzed using a revised PSO (rPSO) model, which explicitly accounts for adsorbate and adsorbent concentrations. A global fit to the PSO model demonstrated that the rate constant was independent of the adsorbent concentration, supporting its application as a robust descriptor of the adsorption process. GLHP showed good adsorption performance, following the Sips adsorption isotherm and Thomas model for batch and column setup, respectively, demonstrating the potential as a scalable, low-cost biosorbent for fast and efficient Cd(II) removal from contaminated waters. Full article

Wet coffee pulp residues (WCPRs) are typically underutilized, and their accumulation increases alongside coffee production, generating significant environmental impacts. This study proposes a sustainable valorization approach through hydrothermal treatment followed by membrane filtration for the production of xylooligosaccharides (XOSs). Extractive-free WCPR contained 35.4% structural carbohydrates (20.4% cellulose and 15.0% hemicellulose) and 27.0% lignin. Hydrothermal treatments (180 °C, 3 °C min⁻¹, 15–60 min) were performed with and without citric acid as an organic catalyst. The acid-assisted treatment (T4) enhanced hemicellulose depolymerization and xylose release (16 g·kg⁻¹ dry biomass), whereas milder, non-acidic conditions (T3) promoted the selective formation and recovery of short-chain XOS, reaching cumulative biomass-normalized yields of up to 14 g·kg⁻¹ of xylobiose (X2) and 9 g·kg⁻¹ of xylotriose (X3). Subsequent membrane processing (UF–DF–NF) enabled progressive purification and enrichment of XOS fractions. Diafiltration was identified as the main step governing XOS enrichment, whereas nanofiltration primarily refined separation by directing monomeric sugars to the permeate rather than substantially increasing XOS yields. Additionally, Multiple Factor Analysis (MFA) integrated process and compositional variables, explaining 79.6% of the total variance. Dimension 1 represented process intensity and xylose transport, while Dimension 2 reflected molecular-weight-driven XOS fractionation. The acid-assisted process (T4) exhibited a distinct multivariate signature, characterized by enhanced carbohydrate mobilization and improved XOS recovery with reduced dependence on dilution. Overall, coupling hydrothermal pretreatment with membrane fractionation proved to be an efficient, and environmentally friendly strategy for coffee by-product valorization, consistent with hemicellulose-first biorefinery models and the principles of the circular bioeconomy. Full article

Concentrated wastewater streams, like vacuum blackwater (VBW), pose significant management challenges due to their high organic strength and pathogen loads. This review evaluates an integrated biorefinery model employing sequential black soldier fly larvae (BSFL) bioconversion and thermophilic anaerobic digestion (TAD) as a circular solution for effective VBW management. The BSFL pretreatment facilitates bio-stabilization, mitigates ammonia inhibition via nitrogen assimilation, and initiates contaminant degradation. However, this stage alone does not achieve complete hygienization, as it fails to inactivate resilient pathogens, including helminth eggs and spore-forming bacteria, thus precluding the safe direct use of frass as fertilizer. By directing the frass into TAD, the system addresses this limitation while enhancing bioenergy recovery: the frass serves as an optimized, nutrient-balanced substrate that increases biomethane yields, while the sustained thermophilic conditions ensure comprehensive pathogen destruction, resulting in the generation of a sterile digestate. Additionally, the harvested larval biomass offers significant valorization flexibility, making it suitable for use as high-protein animal feed or for conversion into biodiesel through lipid transesterification or co-digestion in TAD to yield high biomethane. Consequently, the BSFL-TAD synergy enables net-positive bioenergy production, achieves significant greenhouse gas mitigation, and co-generates digestate as sanitized organic biofertilizer. This cascading approach transforms hazardous waste into multiple renewable resources, advancing both process sustainability and economic viability within a circular bioeconomy framework. Full article

To optimize and model the fermentation process of Beauveria bassiana, adsorbed carrier solid-state fermentation (ACSSF) was used with rice husk as the inert support. The sample pretreating method was improved by combining homogenization and ultrasonic treatment after dry crushing; the large particles (100–1000 μm in size) were broken and the content of small particles (2–100 μm in size) increased, and the relative standard deviation of the biomass detection method was as low as 3.32% (intra-day) and 3.75% (inter-day). The most suitable carbon source—cassava starch—and the most suitable nitrogen source—corn steep liquor powder (CSLP)—were screened from multiple carbon and nitrogen sources. Through single-factor optimization and an artificial neural network combining genetic algorithm optimization, the optimal recipe including cassava starch 0.0314 g·cm⁻³, CSLP 0.004885 g·cm⁻³ and water 0.2630 g·cm⁻³ was obtained, and the highest biomass yield was verified as 0.1379 g·cm⁻³, which was 45.0% higher than the original recipe before the optimization (0.0951 g·cm⁻³). The modeling of microbial growth was based on the Logistic model and executed by nonlinear regression with the R² value as high as 0.9525 and absolute value of the residues completely under 0.003 g·cm⁻³, which validated not only the feasibility of modeling the growth kinetics of B. bassiana using total biomass content, but also the reliability of the improved biomass pretreating and determination method. Full article