Biomass Conversion and Biorefinery最新文献

Dye wastes discharged into water bodies without proper treatment from various industries pose significant environmental hazards due to their carcinogenic, mutagenic, and highly toxic nature. Traditional dye wastewater treatment methods often achieve limited degradation efficiencies, typically between 40 and 60%. In response, various advanced oxidation processes (AOPs) have emerged, offering improved degradation rates of 80 to 90%. However, AOPs are associated with high-energy consumption, maintenance costs, and sludge disposal challenges, which have led to increased interest in oxidase enzymes as alternatives, offering similar dye degradation capabilities with zero disposal costs, eco-friendly production, and reduced energy consumption. Among the oxidase enzymes, laccase, derived from bacteria, fungi, plants, and insects, has demonstrated up to 90% dye degradation efficiency, with and without a mediator system. Laccase-treated samples showed a 65% reduction in toxicity (p < 0.05) and a 70% improvement in water quality metrics compared to untreated wastewater. This review comprehensively examines the enzymatic decolorization of various azo dyes using laccase, highlighting its potential for industrial pollution abatement by exploring the mechanisms, efficiency, and practical applications of laccase in treating dye wastewater, aiming to provide a thorough understanding of its role in mitigating environmental pollution from industrial sources.

In this study, a detailed simulation model of steam-only gasification of pine sawdust with limestone for in situ CO₂ capture and simultaneous tar elimination is developed using the ASPEN plus simulator. The predicted results were compared with the experimental data available in the literature, and a good agreement was found. After validating the model, a parametric study was performed to investigate the influence of operational conditions on the product gas composition and the gasification characteristics. In order to evaluate the reactivity of carbonation reaction in terms of tar destruction and CO₂ absorption, two parameters named CO₂ capture ratio (CCR) and tar cracking ratio (TCR) are also defined. According to the predicted results, higher temperature and introducing more sorbent particles are favorable for promoting the H₂ production and tar elimination; however, enhancing H₂ production and tar conversion is marginal above CaO/biomass ratio (C/B) of 1.5. The addition of steam not only increased H₂ content and H₂ yield by promoting water–gas shift reaction but also apparently enhanced tar reforming/cracking and char conversion. The predictions also showed that the limestone can play the role of both CO₂ absorber and tar converter at low temperature (T < 800 °C); however, it only acts as a catalyst for tar conversion at high temperature (T > 800 °C). For C/B > 1.5, CCR showed a slight increase, implying that less CO₂ was captured as the C/B increased from 1.5 to 2.0.

This study investigates the use of chitin extracted from dead sea urchin shells (testa) to enhance the mechanical and physical properties of vinyl-based composites made using pineapple fiber. The chitin biopolymer is extracted via the thermo-chemical method and mixed with resin before making a composite. The composites were fabricated using the hand layup method and tested in accordance with the American Society for Testing and Materials (ASTM) standards. The resulting composites underwent a series of rigorous examinations to evaluate their mechanical performance, fatigue resistance, wear behavior, and hydrophobicity. Results demonstrated the synergistic effect of combining pineapple fiber and chitin in vinyl ester composites across various compositions. The mechanical properties were improved to higher up to C4 (chitin up to 15 vol. % and pineapple fiber of 40 vol. %) composite after that decreased. However, the wear resistance improved with higher chitin content, as evidenced by a reduced coefficient of friction and specific wear rate. Moreover, an extended fatigue life cycle of 17,732 is observed at 75% of ultimate tensile stress in the C4 composite. The contact angle measurements indicated a retained hydrophilicity with an angle of 86⁰ for the C5 composite. These findings provide crucial insights for advanced material engineering applications, highlighting the significant enhancement in mechanical properties with the incorporation of chitin derived from sea urchin shells. The comprehensive characterization reveals the multifaceted improvements brought about by chitin, paving the way for the development of eco-friendly and high-performance composite materials.

Here, we present the production of carbonaceous bioadsorbent derived from Bidens pilosa L. invasive plant biomass. The bioadsorbent, pyrolyzed at 400 °C, was selected to assess the adsorption performance against ciprofloxacin antibiotic and crystal violet dye from water. This bioadsorbent exhibited a porous structure with a surface area of 4.0 m² g⁻¹ and a point of zero charge of 7.7. To optimize simultaneous removal conditions, a Box-Behnken design and response surface methodology were employed. The model predicted the optimum condition at a dosage of 1.23 g L⁻¹, a ciprofloxacin concentration of 12.82 mg L⁻¹, a crystal violet concentration of 20.5 mg/L, and pH of 3. Notably, the tested values closely matched the predicted values. Additionally, kinetic and isotherm models were applied, indicating excellent adherence to pseudo-first and second-order kinetics, as well as Langmuir and Freundlich isotherms, respectively. Due to high adsorption capacities, i.e., 31.89 mg/g for ciprofloxacin and 58.42 mg g⁻¹ for crystal violet of the bioadsorbent, it is proposed that the conversion of Bidens pilosa L. invasive plant biomass into bioadsorbents is both feasible and sustainable for the simultaneous removal of antibiotics and dyes from water.

In recent times, due to non-renewable resources, construction operations have resulted in significant quantity reductions. Millions of hazardous mineral wastes are produced as a result, and there are also significant amounts of greenhouse gas emissions. To overcome the drawbacks of the existing methodologies, an innovative approach is introduced in this study which is based on the renewable materials which results in low environmental impact and cost. In recent times, the cellulosic materials have been utilized in the concrete technology. Since MCC has the hydrophilic character and water retention capability properties, it can be utilized in cement-based materials which is crucial for the construction. This article describes the use of naturally derived renewable microcrystalline cellulose (MCC) from palm fruit (PF) to reinforce cement. The physical, thermal, chemical, and mechanical properties of PF-MCC are analyzed. The functional groups peaks of PF-MCC are studied from FTIR analysis; XRD analysis reported the crystallinity index and crystalline size to be about 72.13% and 29.6 nm. The higher absorbance is seen at 354 nm by the UV analysis, and the thermal degradation at three stages is resulted from TGA analysis, and the peak is found at (327.27^circ{rm C}). From the EDX analysis, the oxygen and carbon dominate the composition, constituting of about 45.3% and 26.7%, respectively. The addition of the PF-MCC with the M30 grade cement concrete as fillers resulted in a better compressive strength by 10.4% and tensile strength by 9.3%. Thus PF-MCC results in superior characteristics which can be utilized as the eco-filler in the construction industry.

The present study explored the genomic capacities of bacterial isolates Enterobacter cloacae AAK_M13, Bacillus subtilis AAK_M29, and Serratia marcescens EGD-HP20 for enhanced hydrolysis of proteinaceous wastes. Genome annotation showed conditionally expressed genes for degrading complex organic substrates thus indicating the metabolic versatility of the isolates which was also validated by plate assay. Of the different subsystems, 28, 24, and 54 annotation hits were associated with protein degradation in the three isolates respectively coding for peptidases of the di-, serine-, omega-, amino-, metalloendo-, and metallocarboxy-peptidase groups. Considering that high concentration of metals in the environment could interfere with the spatial structure of enzymes thereby inhibiting the microbial metabolism, the annotation of genes encoding metal resistance enzymes such as CopA (copper resistance), ArsC and ArsB (arsenic resistance), and yieF (chromium resistance) was significant. Validation of genomic capacities for extracellular proteolytic enzymes revealed the highest protease production between 100 and 200 U/mL min in case of strain EGD-HP20 that was also reflected from the highest soluble protein generation of 198–416 mg/mL during pre-treatment and hydrolysis of protein rich substrates (PRS). Batch studies on biomethanation led to highest methane yield from PRS hydrolysed in presence of strain EGD-HP20, such as soybean flour (270–275 mL/g VS added) followed by meat extract (266 mL/g VS added) and egg white (227 mL/g VS added) in comparison to the respective untreated/un-augmented PRS thus indicating the advantage of bioaugmentation/pre-treatment. The study suggests that deciphering the genes governing the protein degradation pathways and conversion of complex organics could enable the development of bioaugmentation strategies using bacterial strains for efficient biomenthanation.

Due to resource scarcity and habitat damage, fossil fuels—especially oil and gas—are unsustainable. Recently, scientists have investigated biotechnology and microbiology as solutions for carbon-free, renewable, and alternative energy sources. A modern study shows that bacteria degrade inorganic and organic wastewater pollutants. Since they clean wastewater and generate electricity, microbial fuel cells (MFCs) are the ideal response to the concerns listed earlier. MFCs struggle with electron transport issues due to a lack of anode performance. Thus, current research focuses on the production of anode from biomass waste with minimal effort. This work developed a graphene oxide (GO) electrode using local Moringa biomass powder and found that waste-derived GO yielded 175 mV in 16 days with a power density of 1.49 mW/m². The calculated internal resistance was 796 ῼ, while the external resistance was 1000 ῼ. It seems that electron transportation works effectively. Wastewater treatment is an additional focus for this work. Meanwhile, the inoculation source contains Pb and Hg. The removal efficiency was remarkable, such as Pb = 75.10% and Hg = 65%. Additionally, a thorough analysis of the mechanism and future prospects is also enclosed.

The nano-biocomposites are the combination of natural and synthetic fibers, and they are indeed the most promising materials for many industrial applications. In the present study, the reinforcement Anogeissus latifolia (AL) gum powder of 40% is mixed with polyester (P) of 60% to produce a unique hybrid polyester (ALP) resin matrix; the same is fed with three different volume fractions of 1%, 3%, and 5% fly ash nano powder (FANP) as a binding agent. These compositions were applied to abaca (AB), hemp (HE), and kenaf (KE) mats to produce the individual three layers biocomposite fibers. According to experiment results, the untreated AB fiber mats supplemented with ALP matrix resin at 3% vol% of FANP have better compression and flexural strengths measuring 39.2 MPa and 168.2 MPa, respectively Furthermore, thermal conductivity, hybrid resins, and nano-biocomposites are subjected to thermogravimetric analysis (TGA) and scanning electron microscope (SEM) analyses.

Recently, semiconductor materials have attracted significant interest due to its remarkable catalytic activity. Heterogeneous catalysts play a crucial role in degrading organic dyes and their hazardous by-product, which threaten both aquatic and terrestrial ecosystems when released into wastewater. In this study, we follow the co-precipitation technique to synthesize cobalt-ferrite (CoFe₂O₄) and nickel-ferrite (NiFe₂O₄). Subsequently, produce five distinctive nanocomposite beads, decorated with chitosan: Chi-CoFe₂O₄ − I, Chi-CoFe₂O₄ − II, Chi-NiFe₂O₄ − I, and Chi-NiFe₂O₄ − II, all within an acidic aqueous environment. Different characterization was performed specially the Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) analysis, to check the morphology of the synthesized beads. Most importantly, the synthesized novel beads were then utilized for the photo-degradation of Organic dyes, mostly used in industries, i.e., Eriochrome black T (EBT), and Congo red (CR). The remarkable results revealed a staggering 93% degradation of EBT dye after just 120 min under visible light exposure. Simultaneously, CR dye shows an impressive 93% degradation just within 120 min, through Chi-NiFe₂O₄ − II. While, the TOF were 1257.5 kg⁻¹ s⁻¹, 1287 kg⁻¹ s⁻¹, 1318.18 kg⁻¹ s⁻¹, 1363 kg⁻¹ s⁻¹, and 1393 kg⁻¹ s⁻¹. Furthermore, the turnover numbers were 2.26 × 10^7 kg⁻¹ s⁻¹, 2.3 × 10^7 kg⁻¹ s⁻¹, 2.37 × 10^7 kg⁻¹ s⁻¹, 2.45 × 10^7 kg⁻¹ s⁻¹, and 2.5 × 10^7 kg⁻¹ s⁻¹ for chitosan beads, Chi-CoFe₂O₄ − I, Chi-CoFe₂O₄ − II, Chi-NiFe₂O₄ − I, and Chi-NiFe₂O₄ − II respectively. This study shows the great potential of synthesized nanocomposite beads for degrading organic dyes from wastewater. This study will be a great addition to future environmental studies.

Carbon-based nanomaterials were prepared using a simple microwave-assisted hydrothermal carbonization method, with Chondrus crispus and Palmaria palmata algae as a sustainable feedstock. These materials were thoroughly characterized by FTIR spectroscopy, elemental microanalysis, and XPS analysis. The resulting hydrochars effectively removed ciprofloxacin (CIP), an antibiotic, and malachite green (MG), an organic dye, both of which are pollutants posing threats to ecosystems and public health. The hydrochar derived from Chondrus crispus (HC-Cho-MW) demonstrated superior performance, following a cooperative adsorption process well-described by the Dubinin–Radushkevich isotherm. It exhibited maximum adsorption capacities of 350 mg.g⁻¹ for CIP and 136 mg.g⁻¹ for MG, at 25ºC and pH 6. These values surpass those of previously reported hydrochars and are competitive with certain activated carbons. The pseudo-second-order model provided the best fit for the kinetic data, with film diffusion predominant at specific intervals. The adsorption of CIP and MG was exothermic and entropically favorable for both hydrochars. The small ΔH values (-9.85 to -23.26 kJ.mol⁻¹) suggest that physisorption predominantly governed the overall adsorption mechanism, although electrostatic interactions may also contribute. The hydrochars could be regenerated and reused to remove CIP and MG over three consecutive cycles. These results highlight the potential of using renewable and readily available algae biomass as a precursor for sorbents to remove pollutants from environmental water. This approach utilizes highly efficient microwave heating and avoids costly activation processes.