Lignin Fragments Research Articles

A green strategy to realize the high value utilization of lignin for hydrogel formation

Grafting lignin extracted from pulping black liquor onto hydrogel not only endows hydrogel with strong adsorption capacity, but also realizes the high value utilization of lignin, thereby alleviating the environmental pressure caused by the exhaust gas generated by direct combustion of black liquor. However, those lignin fragments have lost generous active functional groups as the high temperature polycondensation during industrial production, restricting the improvement of lignin-based hydrogel adsorption capacity. Herein, we propose a strategy combining amination and oxidation to prepare lignin derivatives with low molecular weight and high activity groups. The introduced amino groups promote the Cα-Cβ cleavage of β-O-4 unit and the oxidation treatment converts S-unit hydroxyl to carboxyl. The hydrogel obtained by grafting aminated-oxidized-lignin shows satisfactory adsorption performance with a methylene blue adsorption capacity of 697.47 mg/g (vs. 195.12 mg/g for pristine hydrogel). The retention ability has also been greatly improved that only 0.43 % of the adsorbed methylene blue is released even after 96 h (vs. 5 % within just 12 h for pristine hydrogel). This work not only provides a new strategy for the high-value utilization of biomass resources, but also offers a new idea for the preparation of hydrogels with high adsorption performance.

Solid-State Structures and Properties of Lignin Hydrogenolysis Oil Compounds: Shedding a Unique Light on Lignin Valorization

This article explores the important, and yet often overlooked, solid-state structures of selected bioaromatic compounds commonly found in lignin hydrogenolysis oil, a renewable bio-oil that holds great promise to substitute fossil-based aromatic molecules in a wide range of chemical and material industrial applications. At first, single-crystal X-ray diffraction (SCXRD) was applied to the lignin model compounds, dihydroconiferyl alcohol, propyl guaiacol, and eugenol dimers, in order to elucidate the fundamental molecular interactions present in such small lignin-derived polyols. Then, considering the potential use of these lignin-derived molecules as building blocks for polymer applications, structural analysis was also performed for two chemically modified model compounds, i.e., the methylene-bridging propyl-guaiacol dimer and propyl guaiacol and eugenol glycidyl ethers, which can be used as precursors in phenolic and epoxy resins, respectively, thus providing additional information on how the molecular packing is altered following chemical modifications. In addition to the expected H-bonding interactions, other interactions such as π–π stacking and C–H∙∙∙π were observed. This resulted in unexpected trends in the tendencies towards the crystallization of lignin compounds. This was further explored with the aid of DSC analysis and CLP intermolecular energy calculations, where the relationship between the major interactions observed in all the SCXRD solid-state structures and their physico-chemical properties were evaluated alongside other non-crystallizable lignin model compounds. Beyond lignin model compounds, our findings could also provide important insights into the solid-state structure and the molecular organization of more complex lignin fragments, paving the way to the more efficient design of lignin-based materials with improved properties for industrial applications or improving downstream processing of lignin oils in biorefining processes, such as in enhancing the separation and isolation of specific bioaromatic compounds).

Sucrose-derived porous carbon catalyzed lignin depolymerization to obtain a product with application in type 2 diabetes mellitus

As the most important phenolic biopolymer in nature, lignin shows promising application potentialities in various bioactivities in vivo and in vitro, mainly including antioxidant, anti-inflammatory, hypolipidemic, and antidiabetic control. In this work, several carbon-based solid acids were synthesized to catalyze the fragmentation of organosolv lignin (OL). The generated lignin fragments, with controllable molecular weight and functional groups, were further evaluated for their application in the prevention and treatment of type 2 diabetes mellitus (T2DM). The results suggested that the urea-doped catalyst (SUPC) showed a more excellent catalytic performance in producing diethyl ether insoluble lignin (DEIL) and diethyl ether soluble lignin (DESL). In addition, the lignin fragments have a good therapeutic effect on the cell model of T2DM. Compared with the insulin resistance model, DEIL obtained by catalytic depolymerization of OL with SUPC could improve the glucose consumption of insulin-resistant cells. Moreover, low-concentration samples (50 μg/mL) can promote glucose consumption (19.7 mM) more than the traditional drug rosiglitazone (17.5 mM). This work demonstrates the prospect of depolymerized lignin for the prevention and treatment of T2DM and provides a new application field for lignin degradation products.

Lignin Structural Characterization and Its Antioxidant Potential: A Comparative Evaluation by EPR, UV-Vis Spectroscopy, and DPPH Assays.

The natural aromatic polymer lignin and its lignin-like oligomeric fragments have attracted attention for their antioxidant capacity and free radical scavenging activities. In this study, a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was employed to assess the antioxidant capacity of fractionated and partially depolymerized organosolv lignin by electron paramagnetic resonance (EPR) and UV-Vis spectroscopy. The results show significant antioxidant activity for both the lignin and oligomeric fragments, with the EPR measurements demonstrating their efficiency in quenching the free radicals. The EPR data were analyzed to derive the kinetic rate constants. The radical scavenging activity (RSA) of lignins was then determined by UV-Vis spectroscopy and the results were compared with the EPR method. This two-method approach improves the reliability and understanding of the antioxidant potential of lignin and its derivatives and provides valuable insights for their potential applications in various industries, including pharmaceuticals, food preservation, and cosmetics.

Photocatalytic β-O-4 bond cleavage in lignin models and native lignin through CdS integration on titanium oxide photocatalyst under visible light irradiation

Converting lignin, a key sustainable biopolymer, into valuable oxygen-containing compounds is a significant challenge. To address such a challenge, photocatalytic self-transfer hydrogenolysis strategy is employed utilizing a CdS(x%)/TiO2 heterojunction photocatalyst, with minimal CdS loading on TiO2. The CdS(3 %)/TiO2 catalyst, under blue light, dehydrogenates HCα–OH groups, transferring hydrogen to Cβ–O bonds, cleaving β-O-4 ether bonds in lignin model compounds yielding over 95 % phenols and acetophenones. It utilizes glyceryl moieties as a hydrogen source, yielding ∼ 24 % of diverse lignin monomer derivatives from teak lignin. Improved charge separation in the CdS(3 %)/TiO2 catalyst is revealed by electrochemical and spectral analyses and exhibits delayed charge carrier recombination. Scavenging studies confirm a type II charge transfer mechanism and support visible-light-driven lignin fragmentation. The present photocatalytic process offers a promising, cost-effective approach for converting lignin into valuable aromatic compounds, advancing renewable biomass-derived chemicals.

Mechanochemical cleavage of wheat lignin into a more homogeneous fraction

Lignin, the second most abundant biopolymer in earth, represents nature’s largest carbon sources, has high polydispersity and uncertain reactivity, that limit efficient modification/degradation and use of products obtained. In order to decrease by mechanochemical means the average molecular mass and polydispersity of lignin fragments of the CIMV organosolv lignin named Biolignin™, we applied a sodium hydroxide-assisted planetary ball milling process. Experimental conditions were first optimized on purified Biolignin™ then to Biolignin™ without prior purification in 20 mL jars before applying it successfully to a 500 mL planetary ball milling apparatus. Extensive, quantitative HSQC NMR, IR and GPC studies, overtaken supported our three most important findings: reduction of the needed quantity of sodium hydroxide of 75 % compared to the literature, obtention of halve (-51 %) the occurrence of β-O-4’ linkages in lignin fragment, an optimum of 14 wt% of moisture is useful in the degradation process.

Photoinduced Lignin C α -C β Bond Cleavage and Chemodivergent Functionalization via Iron Catalysis.

The photocatalytic conversion of lignin into value-added chemicals especially those functionalized molecules represent one of the most important strategies for sustainable and environmental-friendly development. Cleavage of C-C bonds in lignin under mild photocatalytic conditions for refining lignin into useful molecules is meaningful but challenging. Meanwhile, the assembly of diverse functional groups into active lignin fragments during the depolymerization is of great challenging. Herein, using cheap iron catalysts under visible light irradiation, the highly selective and efficient cleavage of Cα-Cβ bond in lignin is realized via ligand-to-metal charge transfer (LMCT) and hydrogen atom transfer (HAT) processes. The subsequent divergent functionalization of generated lignin fragment-based radical intermediates enables an efficient formation of diverse functionalized molecules. This method is also effective for cleavage of Cα-Cβ bond in native lignin, yielding two identified benzaldehyde monomers in a total yield of 8.7 wt%.

Regularities in mercury cation sorption by a lignin-based sulfur-containing sorbent

The unfavorable environmental situation in the town of Usolye-Sibirskoye (Irkutsk Oblast, Russia) determines the relevance of investigating and applying a new lignin-based sulfur-containing sorbent for purification of groundwater from mercury compounds. The sorbent was synthesized on the basis of waste products of epichlorohydrin (1,2,3-trichloropropane), sulfur, and lignin. The IR spectrum of the sorbent under study showed the presence of an S–S bond in the region of 445–465 cm-1. Intensive absorption of Hg2+ ions in the regions of 2800–2950 cm-1 (valence vibrations of C–H bonds in CH and CH2 groups) and 1460 cm-1 (deformation vibrations in CH2 group) was observed. Absorption of Hg2+ ions by lignin fragments was accompanied by a change in the vibration band of S–S bonds, which splits into two bands of higher frequencies than the νS–S band in the original sorbent. The optimum sulfur content, which ensures the maximum sorption activity of the sorbent, was found to be 53.25%. The mercury sorption isotherms at 20 and 60 °C are described by parabolic dependencies with determination coefficients of 98.9 and 98.6 %, respectively. The kinetic curve at 20 °C and 40 °C is approximated by a hyperbola and a cubic polynomial with determination coefficients of 97.9 and 96.2 %, respectively. The reaction order (first order at 20 °C and second order at 40 °C) and the reaction rate constant (0.0876 min-1 at 20 °C and 0.00014 min-1 at 40 °C) were determined. At 20 °C, the sorption rate of Hg2+ was established to be significantly higher and the sorption time to be faster than those at 40 °C. Therefore, mercury sorption by the proposed sorbent should be carried out at 20 °C in order to reduce energy consumption.

Ethyl acetate fractionation improved the homogeneity and purity of CAOSA-extracted lignin

Lignin separated from the pulping and bio-refining industry is a cross-linked organic phenolic polymer and the most abundant renewable aromatic resource. However, its wide molecular weight distribution, inhomogeneity and complex functional groups are the factors restricting the application of lignin. The preparation of lignin with simple structures and low dispersity by fractionation is one of the main methods to transform lignin into higher-value materials. In this study, lignin fragments with lower dispersibility (Đ) were separated from CAOSA-extracted bamboo lignin by continuous organic solvent fractionation involving ethyl acetate, ethanol, acetone and dioxane/water (95:5). The lignin fragments extracted by ethyl acetate possessed a lower molecular weight (821 g/mol), lower glass transition temperature (Tg), higher purity and phenolic hydroxyl content (0.370 mmol/g). This method unlocked the versatility of the lignin components and provided a reference for the application of lignin in resin, rubber, antioxidant, asphalt and adhesive.

Co-production of fermentable sugars and highly active lignin from eucalyptus via a mild preprocessing with diethylene glycol and chromic chloride

Eucalyptus was pretreated with diethylene glycol catalyzed by 0.02 mol/L CrCl3 for 10 min, resulting in 91 % delignification and 98 % cellulose recovery, with trace fermentation inhibitors generated. After the mild pretreatment, the accessibility and affinity of cellulase to eucalyptus was enhanced, especially since enzyme adsorption rate increased by 1.6-fold. Therefore, glucose yield of pretreated eucalyptus was 7.9-fold higher than that of untreated eucalyptus after hydrolyzed 48 h, in which the maximum glucose concentration reached 62 g/L from eucalyptus by adding Tween 80. According to the characterization analysis, the structure of the eucalyptus lignin-carbohydrate complexes structure was destroyed during the pretreatment, while lignin fragments was likely reacted with diethylene glycol to form the stabilized aromatic ethers. Moreover, the extracted Deg-lignin exhibited better performances than commercial alkali lignin such as higher fluorescence intensity, less negative surface charge, and lower particle size. The mild pretreatment method with diethylene glycol and CrCl3 provided a promising approach for co-production of fermentable sugars and high activity lignin from lignocellulosic biomass.

Differential Studies on the Structure of Lignin-Carbohydrate Complexes (LCC) in Alkali-Extracted Plant Hemicelluloses.

Hemicellulose extracted by alkali treatment is of interest because of the advantages of its intact sugar structure and high degree of polymerization. However, the hemicellulose extracted by alkali treatment contained more lignin fragments and the presence of a lignin-carbohydrate complex (LCC), which affected the isolation and purification of hemicellulose and its comprehensive utilization. Therefore, the evaluation of the LCC structure of different types of lignocellulosic resources is of great significance. In this study, the LCC structures of hardwoods and Gramineae were enriched in alkaline systems. Information on the composition, structural proportions, and connection patterns of LCC samples was discussed. The similarities and differences between the LCC structures of different units of raw materials were comparatively studied. The results indicated that the monosaccharide fractions were higher in the LCC of Gramineae compared to hardwoods. The composition of the lignin fraction was dominated by G and S units. The phenyl glycosidic (PhGlc) bond is the predominant LCC linkage under alkali-stabilized conditions. In addition, Gramineae PhGlc types are more numerous compared to hardwoods. The results of the study provide insights into the differences in the chemical composition and structural features of LCC in different plants and provide important guidance for the optimization of the process of purifying hemicellulose.

Analytical Pyrolysis of Soluble Bio-Tar from Steam Pretreatment of Bamboo by Using TG-FTIR and Py-GC/MS.

Steam pretreatment at high temperatures enables fresh bamboo to possess antifungal and antiseptic properties. The process produces a large amount of wastewater that urgently needs to be recycled. Soluble bio-tars derived from wastewater under low-temperature (LTS-tar) and high-temperature (HTS-tar) steam pretreatments of moso bamboo were studied with a thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FTIR) and pyrolysis-gas-chromatography/mass spectrometry (Py-GC/MS). Thermogravimetric analysis showed that in the three stages of the thermal decomposition process, the final residue of the bamboo and HTS-tar had two main peaks of 0.88 wt% and 6.85 wt%. The LTS-tar had much more complicated thermal decomposition behavior, with six steps and a high residue yield of 23.86 wt%. A large quantity of CH4 was observed at the maximum mass loss rates of the bamboo and bio-tars. Acids, aldehydes, ketones, esters, and phenolic compounds were found in the pyrolysis products of the bamboo and soluble bio-tars. Both bio-tars contained carbohydrates and lignin fragments, but the LTS-tar under mild steam conditions had more saccharides and was much more sensitive to temperature. The lignin in the bamboo degraded under harsh steam conditions, resulting in high aromatic and polymeric features for the HTS-tar. The significant differences between LTS-tar and HTS-tar require different techniques to achieve the resource utilization of wastewater in the bamboo industry.

Role of the molecular structure of humified organic matter in rice plant response to environmental lead pollution.

Humified organic matter has been shown to decrease Pb toxicity in plants. However, there are still gaps in our understanding of the mechanism by which this phenomenon occurs. In this study, we aimed to assess the ability of humic substances (HSs), humic acids (HAs), and fulvic acids (FAs) to enhance defense mechanisms in rice plants under lead (Pb)-stressed conditions. HS fractions were isolated from vermicompost using the chemical fractionation methodology established by the International Humic Substances Society. These fractions were characterized by solid-state NMR and FTIR. Chemometric analysis was used to compare humic structures and correlate them with bioactivity. Three treatments were tested to evaluate the protective effect of humic fractions on rice plants. The first experiment involved the application of humic fractions along with Pb. The second comprised pretreatment with humic fractions followed by subsequent exposure to Pb stress. The third experiment involved Pb stress and subsequent treatment with humic fractions. The root morphology and components of the antioxidative defense system were evaluated and quantified. The results showed that HS + Pb, HA + Pb, and FA + Pb treatment preserved root growth and reduced the levels of O2- and malondialdehyde (MDA) in the roots by up to 5% and 2%, respectively. Pretreatment of the plants with humic fractions promoted the maintenance of root growth and reduced the contents of O2-, H2O2, and MDA by up to 48%, 22%, and 20%, respectively. Combined application of humic fractions and Pb reduced the Pb content in plant tissues by up to 60%, while pretreatment reduced it by up to 80%. The protective capacity of humic fractions is related to the presence of peptides, lignin, and carbohydrate fragments in their molecular structures. These results suggest that products could be developed that can mitigate the adverse effects of heavy metals on agricultural crops.

QM/MM Study Into the Mechanism of Oxidative C=C Double Bond Cleavage by Lignostilbene-α,β-Dioxygenase.

The enzymatic biosynthesis of fragrance molecules from lignin fragments is an important reaction in biotechnology for the sustainable production of fine chemicals. In this work we investigated the biosynthesis of vanillin from lignostilbene by a nonheme iron dioxygenase using QM/MM and tested several suggested proposals via either an epoxide or dioxetane intermediate. Binding of dioxygen to the active site of the protein results in the formation of an iron(II)-superoxo species with lignostilbene cation radical. The dioxygenase mechanism starts with electrophilic attack of the terminal oxygen atom of the superoxo group on the central C=C bond of lignostilbene, and the second-coordination sphere effects in the substrate binding pocket guide the reaction towards dioxetane formation. The computed mechanism is rationalized with thermochemical cycles and valence bond schemes that explain the electron transfer processes during the reaction mechanism. Particularly, the polarity of the protein and the local electric field and dipole moments enable a facile electron transfer and an exergonic dioxetane formation pathway.

The role of glycosylation in non-productive adsorption of cellulase to lignin isolated from pretreated corn stover

Glycosylation, a general post-translational modification for fungal cellulase, has been shown to affect cellulase binding to its substrate. However, the exact impact of glycosylation on cellulase-lignin interaction remain unclear. Here, we demonstrated that the lignin isolated from tetrahydrofuran-pretreated corn stover exhibits strong adsorption capability to cellulase due to its negatively charged and porous structure. For the cellulases with varying glycosylation levels, the less-glycosylated protein showed high adsorption capability to lignin, and that trend was observed for the main cellulase components secreted by Penicillium oxilicum, including endoglucanase PoCel5B, cellobiohydrolase PoCel7A-2, and β-glucosidase PoBgl1. Additionally, N-glycan sites and motifs were examined using mass spectrometry, and protein structures with N-glycans were constructed, where PoBgl1 and PoCel7A-2 contained 13 and 1 glycosylated sites respectively. The results of molecular dynamics simulations indicated that the N-glycans impacted on the solvent-accessible surface area and secondary structure of protein, and the binding conformation of lignin fragment on cellulase, resulting in a decrease in binding energy (14 kcal/mol for PoBgl1 and 13 kcal/mol for PoCel7A-2), particularly for van der Waals and electrostatic interaction. Those findings suggested that glycosylation negatively impacted the lignin-cellulase interaction, providing a theoretical basis for the rational engineering of enzymes to reduce lignin-enzyme interaction.

CHARACTERIZATION OF LIGNIN DISSOLVED DURING ALKALINE SODIUM BOROHYDRIDE AND HYDROGEN PEROXIDE PRETREATMENTS OF SUGAR MAPLE (ACER SACCHARUM)

Sugar maple (Acer saccharum) wood chips were pretreated with aqueous sodium hydroxide, sodium borohydride, and hydrogen peroxide pretreatments, and the characterization (i.e., amount, molar masses, and molar mass distributions) of the lignin dissolved during the pretreatments was performed. Of the applied pretreatments, especially borohydride pretreatments were efficient in dissolving lignin from this feedstock, as 20% to 28% of the dissolved organics were found to consist of dissolved lignin, contributing to 3.4% to 9.0% of the initial wood lignin. Corresponding values for 2.5% and 5.0% alkaline peroxide pretreatments were from 5.9% to 9.2% dissolved lignin of the total dissolved organics and from 1.1% to 3.2% of the initial wood lignin. Additionally, determined molar masses and molar mass distributions indicated that borohydride pretreatments generally led to the formation of smaller-molar-mass lignin fragments when compared to reference pretreatments and to pretreatments conducted with alkaline peroxide process, indicating more efficient lignin degradation caused by borohydride addition. For example, Mn and Mw values of the analyzed reference effluents were 54%-62% and 66%-71% higher when compared to the corresponding borohydride effluents, respectively.

Molecular insights into inhibiting effects of lignin on cellulase investigated by molecular dynamics simulation

The hydrolysis of lignocellulose into fermentable monosaccharides using cellulases represents a critical stage in lignocellulosic bioconversion. However, the inactivation of cellulase in the presence of lignin is attributed to the high cost of biofinery. To address this challenge, a comprehensive investigation into the structure–function relationship underlying lignin-driven cellulase inactivation is essential. In this study, molecular docking and molecular dynamics (MD) simulations were employed to explore the impacts of lignin fragments on the catalytic efficiency of cellulase at the atomic level. The findings revealed that soluble lignin fragments and cellulose could spontaneously form stable complexes with cellulase, indicating a competitive binding scenario. The enzyme’s structure remained unchanged upon binding to lignin. Furthermore, specific amino acid residues have been identified as involved in interactions with lignin and cellulose. Hydrophobic interactions were found to dominate the binding of lignin to cellulase. Based on the mechanisms underlying the interactions between lignin fragments and cellulase, decreased hydrophobicity and change in the charge of lignin may mitigate the inhibition of cellulase. Furthermore, site mutations and chemical modification are also feasible to improve the efficiency of cellulase. This study may contribute valuable insights into the design of more lignin-resistant enzymes and the optimization of lignocellulosic pretreatment technologies. Communicated by Ramaswamy H. Sarma

Valorization of straw biomass into lignin bio-ink, bacterial cellulose and activated nanocarbon through the trade-off alkali-catalyzed glycerol organosolv biorefinery

Integrated lignocellulosic biorefinery that transforms low-value lignocellulose into multiple value-added products is crucial for a low-carbon sustainable development. Herein, a one-pot alkali-catalyzed glycerol organosolv (ALGO) pretreatment-based integrated biorefinery process to directionally produce lignin bio-inks, bacterial celluloses (BCs), and activated nanocarbons (ANCs) was proposed. ALGO pretreatment could modify the structure of dissolved lignins by glycerolysis. The extracted lignin fragments with high-purity (>90 %), uniform with low molecular weight (2500–4000 of Mw), and abundant hydrophilic aliphatic –OH were promising candidates in 3D-printable inks preparation. The glycerolysis reaction during ALGO process also enabled pretreated substrates toward high hydrolyzability and protected pretreatment liquor from generating fermentable inhibitors, making the solid fractions more liable for enzymatic deconstruction and microbial fermentation. Without any detoxification treatments, hydrolysates from ALGO pretreated substrates were used directly as carbon sources for BCs production, resulting in the BC yields were 56 % higher than that of the commercial glucose. The enzymatic hydrolysis residue and BC fermentation waste liquid were synthesized into ANCs via a facile carbonization process, which could further increase the value of ALGO biorefinery. Calculations showed that this ALGO integrated strategy rendered the conversion of ∼75 % lignins in pretreatment liquor to bio-inks and nearly 100 % solid fractions to BCs and ANCs. Unlike the conventional “lignin-first” route to obtain high-purity cellulose by sacrificing the value-adding conversion ability of by-products, the designed technical route in this work achieved a good trade-off between fractionation ability and subsequent conversion potential, inspiring further exploration of the technical correlation between biomass fractionation and bioproduct processing.

Double in-situ lignin modification in surfactant-assisted glycerol organosolv pretreatment of sugarcane bagasse towards efficient enzymatic hydrolysis

Organosolv pretreatment effectively fractionates lignocellulosic biomass for efficient enzymatic hydrolysis, yielding fermentable sugars. However, substantial lignin redeposition on the substrate surface and residual lignin content exacerbate lignin’s inhibitory effects on subsequent enzymatic hydrolysis. An in-situ lignin modification is proposed to address this challenge by incorporating polyethylene glycol (PEG) series into glycerol organosolv (GO) pretreatment. According to the results obtained, PEG-assisted GO pretreated substrate exhibited significantly increased sugar yield during enzymatic hydrolysis, particularly with PEG 4000, showing 35.4% higher glucose yield over 72 h. The improved glucose yield with PEG could be attributed to changes in the physicochemical structure and properties of residual lignin, mitigating its non-productive interaction with cellulase enzymes. PEG's presence in GO pretreatment also increased β-O-4 linkages preservation by 55% and reduced phenolic hydroxyl groups by 28% in lignin fragments versus no surfactants. This outcome resulted from introducing glycerol and PEG hydroxyl tails into the lignin structure, forming α-etherified lignin and rendering it more hydrophilic. Simulations confirmed strong Van Der Waals and hydrogen bonding interactions between lignin units and PEG, hindering lignin fragments repolymerization. Incorporating PEG in the organosolv pretreatment proves highly beneficial for cellulase-mediated lignocellulosic biorefinery, resembling a lignin-first strategy. The optimized process enables efficient biomass utilization for sustainable fuels and chemicals production.

Harnessing Renewable Lignocellulosic Potential for Sustainable Wastewater Purification.

Utilizing renewable lignocellulosic resources for wastewater remediation is crucial to achieving sustainable social development. However, the resulting by-products and the synthetic process characterized by complexity, high cost, and environmental pollution limit the further development of lignocellulose-based materials. Here, we developed a sustainable strategy that involved a new functional deep eutectic solvent (DES) to deconstruct industrial xylose residue into cellulose-rich residue with carboxyl groups, lignin with carboxyl and quaternary ammonium salt groups, and DES effluent rich in lignin fragments. Subsequently, these fractions equipped with customized functionality were used to produce efficient wastewater remediation materials in cost-effective and environmentally sound manners, namely, photocatalyst prepared by carboxyl-modified cellulose residue, biochar-based adsorbent originated from modified lignin, and flocculant synthesized by self-catalytic insitu copolymerization of residual DES effluent at room temperature. Under the no-waste principle, this strategy upgraded the whole components of waste lignocellulose into high-value-added wastewater remediation materials with excellent universality. These materials in coordination with each other can stepwise purify high-hazardous mineral processing wastewater into drinkable water, including the removal of 99.81% of suspended solids, almost all various heavy metal ions, and 97.09% chemical oxygen demand, respectively. This work provided promising solutions and blueprints for lignocellulosic resources to alleviate water shortages while also advancing the global goal of carbon neutrality.