ACS Sustainable Chemistry & Engineering最新文献

Traditional cotton textile dyeing processes are extensively dependent on electrolytes and auxiliaries, generating wastewater laden with hydrolyzed dyes and salts that present substantial environmental risks. This work developed a water-saving and less-salt dyeing method for cotton textiles by integrating deep eutectic solvent (DES) swelling pretreatment. This innovative approach alters the intra- and intermolecular hydrogen bonding of cellulose, inducing structural modifications, such as increased fiber diameter, enhanced amorphous cellulose content, and expanded porous architecture. These changes significantly improve dye accessibility and the uptake efficiency. Among the DES systems evaluated, K₂CO₃-glyceryl DES exhibited the highest S_w% in cotton fibers (59.5%). DES swelling method offers significant advantages over conventional processes, such as reduced environmental impact (e.g., lower water/energy consumption, fewer harsh chemicals), enhanced dye uptake efficiency, or improved fiber integrity. Furthermore, the DES retained its swelling efficacy after multiple recycling cycles, underscoring its reusability. This advancement not only aligns with eco-friendly textile manufacturing goals but also demonstrates economic viability.

In the quest for sustainable energy and environmental preservation, reductive catalytic fractionation (RCF) of lignocellulosic biomass has emerged as a powerful approach to valorize lignin. However, the precise mechanism driving the RCF process remains elusive due to analytical challenges. This study unlocks the mechanism by investigating the Pd/C-catalyzed RCF of birch wood using online high-resolution mass spectrometry (HRMS) for the first molecular-level insights. Real-time evolutions of various monomers, dimers, and oligomers bridged the gap between large lignin fragments and small phenolic products, revealing the stepwise nature of RCF. The process starts with lignin extraction into the liquid phase from the middle lamella to the secondary wall of the cell wall, followed by rapid catalytic depolymerization of the extracted lignin fragments to yield phenolic monomers and dimers. Intriguingly, the evolution of sugar-derived compounds highlights the holocellulose degradation with prolonged reaction times, posing challenges to lignin-first strategies. These findings underscore the importance of fine-tuning RCF conditions to enhance conversion efficiency and minimize side reactions. Moreover, this work highlights the application of advanced HRMS techniques for gaining mechanistic and kinetic insights into liquid-phase reactions, paving the way for more efficient biomass valorization technologies.

An environmentally friendly adsorbent for recovering nuclear energy source U(VI) from wastewater plays a crucial role in resource recovery and environmental preservation. In this work, a double-network aerogel adsorbent composite constructed from sodium alginate, poly(acrylic acid), and NH₂-MIL-125 (NM@SA) was fabricated by a mild method, which was adopted to remove and concentrate U(VI) in the corresponding simulated wastewater samples. According to the results of adsorption kinetic and isotherm models, the adsorption of U(VI) on NM@SA was a monolayer chemisorption process. The maximum adsorption capacity of NM@SA for U(VI) calculated from the Langmuir model was 703.6 mg·g^–1. In addition, the adsorbent maintained excellent adsorption capacity, recoverability, and reuse in large-scale operation. The same abilities can be demonstrated in real seawater environments. Finally, the potential adsorption mechanisms of U(VI) on NM@SA were discussed in conjunction with the experimental determination and characterization results. Overall, this study introduces an advantageous research approach for treating U(VI)-containing radioactive wastewater.

Nitrilase has attracted widespread attention due to its efficiency, specificity, and ecofriendliness in the hydrolysis reactions of nitrile compounds. These enzymes can catalyze various substrates, including aliphatic nitriles and aromatic nitriles. However, high substrate specificity is key to efficient catalysis and high-purity product synthesis. This study aims to enhance the preference of nitrilase for aliphatic nitriles through substrate channel engineering to expand its industrial applications. We developed a semirational design workflow that integrates extensive search and deep optimization strategies, relying on computational tools such as substrate channel modeling and molecular docking to systematically identify and optimize key amino acid residues related to substrate binding. Taking 3-chloropropionitrile as an example, the specific activity of the optimal mutant G191A/L194W increased from 2.47 to 58.35 U·mg^–1, with the substrate conversion rate approaching 100%, while the catalytic activity toward aromatic nitriles significantly decreased. Molecular dynamics simulations revealed the correlation between substrate specificity and channel morphology regulated by W194 and promoted the formation of a specificity-enhanced mutant network. This study provides a structural and mechanistic basis for substrate channel design and enzyme function modification and validates its potential for industrial applications.

This study presents a novel and cost-effective approach to biomass pretreatment that addresses the limitations of conventional methods, which often result in high water and chemical usage as well as the production of chemical-laden wastewater. We investigated the integration of metal oxides (specifically CaO and MgO) for biomass pretreatment and mineral acids (H₂SO₄ or H₃PO₄) for pH adjustment at a high solid loading of 20 wt %. This innovative method allows for direct enzymatic hydrolysis and fermentation of the resulting slurry, effectively eliminating the need for solid–liquid separation and extensive washing. Our findings reveal that hydrolysates from MgO combined with H₃PO₄ or H₂SO₄ were inhibitory to Saccharomyces cerevisiae, resulting in no ethanol production. In contrast, corn stover that was pretreated with CaO and subsequently adjusted to pH with H₃PO₄ demonstrated a higher enzymatic hydrolysis efficiency than the case of adjusting pH with H₂SO₄, achieving over 65% glucan conversion and 80% xylan conversion, along with an ethanol concentration of approximately 33 g/L following separate hydrolysis and fermentation. This enhanced performance can be attributed to reduced osmotic stress, decreased salt toxicity, and minimal formation of inhibitors, as CaO neutralized with H₃PO₄ generated the minimally soluble precipitate Ca₃(PO₄)₂. Furthermore, employing a semisimultaneous saccharification and fermentation process improved sugar utilization efficiency, resulting in an increased ethanol concentration of 46 g/L. The corn stover fermentation residue (CSFR) contained 93% lignin, predominantly of syringyl and guaiacyl types. This study offers a sustainable and scalable method for producing cellulosic ethanol, significantly lowering chemical and water consumption while achieving a high conversion efficiency.

The Na₄Fe₃(PO₄)₂(P₂O₇) (NFPP) cathode material for sodium-ion batteries (SIBs) is modified through a facile yttrium (Y)-doping approach. The crystal structures, surface morphologies, and electrochemical performances of the pristine and Y-doped samples are comparatively investigated. The results indicate that the structure and morphology of the material are almost unchanged after Y doping. Doping with an appropriate amount of Y can enhance the electronic conductivity and electrochemical kinetics of the material, leading to superior electrochemical performance. Among the four samples prepared with different Y-doping levels, the optimum one exhibits the highest capacity of 115.8 mAh g^–1 (0.1C, 2–4 V, 1C = 129 mA g^–1), as well as outstanding cycling stability and rate capability (retaining a capacity of 87.8 mAh g^–1 after 3000 cycles at 20C, with a retention of 92.7%). Furthermore, scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements after cycling reveal that Y doping can stabilize the material structure, thereby further enhancing its lifespan during long-term cycling.