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1.
Molecules ; 29(5)2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38474449

RESUMEN

In this work, a novel sustainable approach was proposed for the integral valorisation of Arctium lappa (burdock) seeds and roots. Firstly, a preliminary recovery of bioactive compounds, including unsaturated fatty acids, was performed. Then, simple sugars (i.e., fructose and sucrose) and phenolic compounds were extracted by using compressed fluids (supercritical CO2 and propane). Consequently, a complete characterisation of raw biomass and extraction residues was carried out to determine the starting chemical composition in terms of residual lipids, proteins, hemicellulose, cellulose, lignin, and ash content. Subsequently, three alternative ways to utilise extraction residues were proposed and successfully tested: (i) enzymatic hydrolysis operated by Cellulases (Thricoderma resei) of raw and residual biomass to glucose, (ii) direct ethanolysis to produce ethyl levulinate; and (iii) pyrolysis to obtain biochar to be used as supports for the synthesis of sulfonated magnetic iron-carbon catalysts (Fe-SMCC) to be applied in the dehydration of fructose for the synthesis of 5-hydroxymethylfurfural (5-HMF). The development of these advanced approaches enabled the full utilisation of this resource through the production of fine chemicals and value-added compounds in line with the principles of the circular economy.


Asunto(s)
Arctium , Arctium/química , Lignina/química , Extractos Vegetales/química , Celulosa , Fructosa
2.
Environ Res ; 248: 118205, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38242421

RESUMEN

This paper presents a techno-economic analysis (TEA) of six (6) scenarios of the kraft lignin catalytic (CFP) and thermal (TFP) fast pyrolysis towards the production of high value-added chemicals (HVACs) and electric energy, based on experimental data from our previous work. ASPEN PLUS was used to simulate the proposed plants/scenarios and retrofitted custom-based economic models that were developed in Microsoft EXCEL. The results showed that scenarios 1 and 2 in which the produced bio-oil is used as fuel for electricity production are the most cost-deficient. On the other hand, scenarios 3 and 6 that utilize the light bio-oil fraction to recover distinct HVACs, along with the use of heavier fractions for electricity production, have showed a significant investment viability, since profitability measures are high. Furthermore, scenarios 4 and 5 that refer to the recovery of mixtures (fractions) of HVACs, are considered an intermediate investment option due to the reduced cost of separation. All the proposed scenarios have a substantial total capital investment (TCI) which ranges from 135 MM€ (scenario 4) to 380 MM€ (scenario 6) with a Lang factor of 6.08, which shows that the CAPEX results are within reason. As far as the comparison of lignin CFP and TFP goes, it is shown that lignin CFP leads to the production of aromatic and phenolic monomers which have a substantial market value, while TFP can lead to important value-added chemicals with a lower OPEX than CFP. A target of return of investment (ROI) of 32% has been set for the selling prices of the HVACs. In summary, this study aims at listing and assessing a set of economic indicators for industrial size plants that use lignin CFP and TFP towards the production of high value-added chemicals and energy production and to provide simulation data for comparative analysis of three bio-oil separation methods, i.e. distillation, liquid-liquid extraction and moving bed chromatography.


Asunto(s)
Lignina , Aceites de Plantas , Polifenoles , Pirólisis , Lignina/química , Biocombustibles , Biomasa
3.
Int J Biol Macromol ; 259(Pt 2): 129140, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38199558

RESUMEN

Plastic wastes accumulated due to food packaging pose environmental threats. This study proposes biopolymeric films containing lignins extracted from potato crop residues (PCR) through organosolv treatment as a green alternative to non-degradable food packaging. The isolation process yielded 43.9 wt% lignins with a recovery rate of 73.5 wt% achieved under optimum conditions at 180 °C with 50 % v/v ethanol. The extracted lignins were then incorporated into a starch matrix to create biocomposite films. ATR-FTIR analysis confirmed interactions between the starch matrix and extracted lignins, and XRD analysis showed the amorphous structure of lignins, reducing film crystallinity. The addition of 1 wt% of extracted lignins resulted in a 87 % reduction in oxygen permeability, a 25 % increase in the thermal stability of the film, and a 78 % enhancement in antioxidant. Furthermore, introducing 3 wt% lignins led to the lowest water vapor transmission rate, measuring 9.3 × 10-7 kg/s·m2. Morphological studies of the films demonstrated a homogeneous and continuous structure on both the surface and cross-sectional areas when the lignins content was below 7 wt%. These findings highlight the potential of using organosolv lignins derived from potato crop residues as a promising additive for developing eco-friendly films designed for sustainable food packaging.


Asunto(s)
Lignina , Solanum tuberosum , Lignina/química , Solanum tuberosum/química , Almidón/química , Embalaje de Alimentos , Antioxidantes/química
4.
Int J Biol Macromol ; 255: 128042, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37977476

RESUMEN

This work describes the chemical and structural characterization of a lignin-rich residue from the bioethanol production of olive stones and its use for nanostructures development by electrospinning and castor oil structuring. The olive stones were treated by sequential acid/steam explosion pretreatment, further pre-saccharification using a hydrolytic enzyme, and simultaneous saccharification and fermentation (PSSF). The chemical composition of olive stone lignin-rich residue (OSL) was evaluated by standard analytical methods, showing a high lignin content (81.3 %). Moreover, the structural properties were determined by Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and size exclusion chromatography. OSL showed a predominance of ß-ß' resinol, followed by ß-O-4' alkyl aryl ethers and ß-5' phenylcoumaran substructures, high molecular weight, and low S/G ratio. Subsequently, electrospun nanostructures were obtained from solutions containing 20 wt% OSL and cellulose triacetate with variable weight ratios in N, N-Dimethylformamide/Acetone blends and characterized by scanning electron microscopy. Their morphologies were highly dependent on the rheological properties of polymeric solutions. Gel-like dispersions can be obtained by dispersing the electrospun OSL/CT bead nanofibers and uniform nanofiber mats in castor oil. The rheological properties were influenced by the membrane concentration and the OSL:CT weight ratio, as well as the morphology of the electrospun nanostructures.


Asunto(s)
Nanofibras , Olea , Lignina/química , Olea/química , Aceite de Ricino , Polímeros , Nanofibras/química , Espectroscopía Infrarroja por Transformada de Fourier
5.
Sci Rep ; 13(1): 18169, 2023 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-37875587

RESUMEN

The advancement in natural fibre composites has replaced synthetic fibres in various commercial sectors. Bamboo species possess high mechanical properties due to their lignocellulosic fibre content, which makes them suitable for engineering applications and potential alternatives to solid wood. However, despite Bamboo being composed of 130 genera and 1700 different species, out of which many still remains underexplored. In this study, we investigated the, Lignocellulosic profiling, fibre strength, and mechanical characterization of two species of Pseudoxytenanthera Bamboo: Pseudoxytenanthera ritchiei, Pseudopxytenanthera stocksii, and the results obtained were compared with Bambusa balcooa, one of the priority species of bamboo identified by The International Plant Genetic Resources Institute (IPGRI). BET (Brunauer-Emmett-Teller) was used to quantify the samples' density, while SEM-EDX and FTIR spectroscopy were used for elemental analysis. The samples were then subjected to tensile test in addition, thermogravimetric analysis and water absorption test were carried out for the three species. The results showed that Pseudoxytenanthera species possessed superior chemical and mechanical characteristics compared to the priority species of bamboo used for composites. Out of the two Pseudoxytenanthera species studied, Pseudoxytenanthera stocksii exhibited the highest values of cellulose, hemicellulose, lignin, pectin, ash, carbon, and silicon, indicating its chemical superiority. Moreover, Pseudoxytenanthera stocksii also showed higher mechanical values for tensile strength, making it suitable for a variety of engineering applications. The TGA values also indicated that Pseudoxytenanthera stocksii is stable at high temperatures when compared with other natural fibres.


Asunto(s)
Bambusa , Celulosa , Celulosa/química , Lignina/química , Bambusa/genética , Pectinas , Estructuras de las Plantas
6.
Int J Biol Macromol ; 253(Pt 2): 126786, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37690637

RESUMEN

Rust powder collected from an archeological iron was evaluated by complementary analyses such as FTIR, XRD, XRF, and SEM/EDX. The analyses revealed that lepidocrocite (L) was the major component in the archeological iron. Coconut husk (CH) can be classified as a type of lignocellulosic biomass of renewable resources that are widely available, especially in coastal areas. In this research, the isolated lignin extracted from CH is being studied as a potential alternative for environmentally friendly applications. The isolated lignin from soda and organosolv pulping went through several analyses such as FTIR, NMR (13C and 2D-HSQC), and TGA analyses. The analyses showed that lignin isolated via soda pulping has superior antioxidant capabilities due to its greater phenolic-OH content compared to lignin isolated from organosolv pulping. The effects of lignin concentrations, pH, and reaction time were utilized in rust conversion studies of an archeological iron. 5 wt% of soda lignin (SL) was revealed as the ideal condition in this rust conversion study with a value of 84.21 %. The treated rust powder with 5 wt% of SL was then further gone through several complementary analyses, which revealed that the treated rust had nearly transformed into an amorphous state.


Asunto(s)
Cocos , Lignina , Lignina/química , Cocos/química , Hierro , Polvos , Espectroscopía de Resonancia Magnética
7.
Plant Commun ; 4(6): 100682, 2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-37691288

RESUMEN

Sporopollenin in the pollen cell wall protects male gametophytes from stresses. Phenylpropanoid derivatives, including guaiacyl (G) lignin units, are known to be structural components of sporopollenin, but the exact composition of sporopollenin remains to be fully resolved. We analyzed the phenylpropanoid derivatives in sporopollenin from maize and Arabidopsis by thioacidolysis coupled with nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS). The NMR and GC-MS results confirmed the presence of p-hydroxyphenyl (H), G, and syringyl (S) lignin units in sporopollenin from maize and Arabidopsis. Strikingly, H units account for the majority of lignin monomers in sporopollenin from these species. We next performed a genome-wide association study to explore the genetic basis of maize sporopollenin composition and identified a vesicle-associated membrane protein (ZmVAMP726) that is strongly associated with lignin monomer composition of maize sporopollenin. Genetic manipulation of VAMP726 affected not only lignin monomer composition in sporopollenin but also pollen resistance to heat and UV radiation in maize and Arabidopsis, indicating that VAMP726 is functionally conserved in monocot and dicot plants. Our work provides new insight into the lignin monomers that serve as structural components of sporopollenin and characterizes VAMP726, which affects sporopollenin composition and stress resistance in pollen.


Asunto(s)
Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Estudio de Asociación del Genoma Completo , Calor , Lignina/química , Lignina/genética , Lignina/metabolismo , Polen/genética , Polen/metabolismo , Rayos Ultravioleta , Zea mays/genética , Zea mays/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
8.
Int J Biol Macromol ; 242(Pt 2): 124706, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37146852

RESUMEN

This study proposes a novel and feasible dissolution and fractionation method of depectinated sugar beet pulp (SBP) in NaOH/Urea/H2O, ionic liquid (IL) and alkaline treatment processes. Interestingly, the complicated structure of SBP can be treated with 30 % H2SO4 to increase the dissolution rate. Scanning electron microscope (SEM) analysis confirmed that the appearance of cellulose and hemicellulose obtained by two methods were different. At the same time, two lignin fractions showed irregular high-density clusters, which were composed of a large number of submicron particles. The crystal structure of two cellulose fractions changed from cellulose I to cellulose II. The thermal stability of cellulose and lignin obtained by ionic liquid was slightly better than that obtained by NaOH/urea/H2O. Results of Fourier transform infrared (FTIR) and 13C NMR showed that the chemical structures of SBP cellulose, hemicellulose and lignin regenerated from NaOH/urea/H2O and ionic liquid were similar.


Asunto(s)
Beta vulgaris , Líquidos Iónicos , Celulosa/química , Lignina/química , Líquidos Iónicos/química , Hidróxido de Sodio , Urea , Azúcares , Hidrólisis
9.
J Oleo Sci ; 72(6): 605-612, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37258214

RESUMEN

Quince fruit powder can be obtained from the waste of the edible product. In this study, we modified the powder with various solvents and investigated its application in Pickering emulsification. The crushed Chinese quince fruit possessed excellent Pickering emulsifying abilities when the water-soluble components were removed. In addition to cellulose, the powder contains hydrophilic pectin and hydrophobic lignin fibers. Similarly, a powder consisting of cellulose and a small amount of lignin without pectin, which was obtained by further solvent treatment, also showed high emulsification performance. Although these two powders had different fiber compositions, their water contact angles were almost equal, and their surface hydrophilicity was lower than that of the cellulose-only powder without emulsification ability.


Asunto(s)
Emulsiones , Frutas , Rosaceae , Celulosa/química , Emulsiones/química , Frutas/química , Lignina/química , Pectinas/análisis , Polvos , Rosaceae/química , Tensoactivos/química , Agua/química
10.
Food Chem ; 416: 135688, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-36905709

RESUMEN

Lignin is a crucial component in the wound tissue of tubers. The biocontrol yeast Meyerozyma guilliermondii increased the activities of phenylalanine ammonia lyase, cinnamate-4-hydroxylase, 4-coenzyme coenzyme A ligase, and cinnamyl alcohol dehydrogenase, and elevated the levels of coniferyl, sinapyl, and p-coumaryl alcohol. The yeast also enhanced the activities of peroxidase and laccase, as well as the content of hydrogen peroxide. The lignin promoted by the yeast was identified as guaiacyl-syringyl-p-hydroxyphenyl type using Fourier transform infrared spectroscopy and two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance. Furthermore, a larger signal area for G2, G5, G'6, S2, 6, and S'2, 6 units was observed in the treated tubers, and the G'2 and G6 units were only detected in the treated tuber. Taken together, M. guilliermondii could promote deposition of guaiacyl-syringyl-p-hydroxyphenyl type lignin by activating the biosynthesis and polymerization of monolignols at the wounds of potato tubers.


Asunto(s)
Lignina , Solanum tuberosum , Lignina/química , Polimerizacion
11.
Int J Mol Sci ; 24(6)2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36982237

RESUMEN

Large amounts of vine shoots are generated every year during vine pruning. This residue still presents many of the compounds found in the original plant, including low molecular weight phenolic compounds and structural compounds such as cellulose, hemicellulose, and lignin. For wine-producing regions, the challenge is to develop alternatives that will increase the value of this residue. This work proposes the full valorization of vine shoots, focusing on the extraction of lignin by mild acidolysis for the preparation of nanoparticles. The effect of the pretreatment solvents (ethanol/toluene, E/T, and water/ethanol, W/E), on the chemical and structural features of lignin, was evaluated. The chemical analysis suggests similar composition and structure regardless of the pretreatment solvent, although lignin isolated after pretreatment of biomass with E/T showed a higher content of proanthocyanidins (11%) compared with W/E (5%). Lignin nanoparticles (LNPs) presented an average size ranging from 130-200 nm and showed good stability for 30 days. Lignin and LNPs showed excellent antioxidant properties (half maximal inhibitory concentration, IC50 0.016-0.031 mg/mL) when compared to commercial antioxidants. In addition, extracts resulting from biomass pretreatment showed antioxidant activity, with W/E presenting a lower IC50 (0.170 mg/mL) than E/T (0.270 mg/mL), correlated with the higher polyphenol content of W/E, with (+)-catechin and (-)-epicatechin being the main compounds detected. Overall, this work shows that the pre-treatment of vine shoots with green solvents can yield (i) the production of high-purity lignin samples with antioxidant properties and (ii) phenolic-rich extracts, promoting the integral reuse of this byproduct and contributing to sustainability.


Asunto(s)
Antioxidantes , Lignina , Lignina/química , Antioxidantes/farmacología , Extractos Vegetales/química , Fenoles/análisis , Etanol , Solventes
12.
Biotechnol Adv ; 64: 108107, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36758651

RESUMEN

Lignin is the most affluent natural aromatic biopolymer on the earth, which is the promising renewable source for valuable products to promote the sustainability of biorefinery. Flavonoids are a class of plant polyphenolic secondary metabolites containing the benzene ring structure with various biological activities, which are largely applied in health food, pharmaceutical, and medical fields. Due to the aromatic similarity, microbial conversion of lignin derived aromatics to flavonoids could facilitate flavonoid biosynthesis and promote the lignin valorization. This review thereby prospects a novel valorization route of lignin to high-value natural products and demonstrates the potential advantages of microbial bioconversion of lignin to flavonoids. The biodegradation of lignin polymers is summarized to identify aromatic monomers as momentous precursors for flavonoid synthesis. The biosynthesis pathways of flavonoids in both plants and strains are introduced and compared. After that, the key branch points and important intermediates are clearly discussed in the biosynthesis pathways of flavonoids. Moreover, the most significant enzyme reactions including Claisen condensation, cyclization and hydroxylation are demonstrated in the biosynthesis pathways of flavonoids. Finally, current challenges and potential future strategies are also discussed for transforming lignin into various flavonoids. The holistic microbial conversion routes of lignin to flavonoids could make a sustainable production of flavonoids and improve the feasibility of lignin valorization.


Asunto(s)
Flavonoides , Lignina , Lignina/química , Biodegradación Ambiental
13.
Int J Biol Macromol ; 233: 123470, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36736974

RESUMEN

This research studies in detail four different assays, namely DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric ion reducing antioxidant potential) and FC (Folin-Ciocalteu), to determine the antioxidant capacity of standard substances as well as 50 organosolv lignins, and two kraft lignins. The coefficient of variation was determined for each method and was lowest for ABTS and highest for DPPH. The best correlation was found for FRAP and FC, which both rely on a single electron transfer mechanism. A good correlation between ABTS, FRAP and FC, respectively, could be observed, even though ABTS relies on a more complex reaction mechanism. The DPPH assay merely correlates with the others, implying that it reflects different antioxidative attributes due to a different reaction mechanism. Lignins obtained from paulownia and silphium have been investigated for the first time regarding their antioxidant capacity. Paulownia lignin is in the same range as beech wood lignin, while silphium lignin resembles wheat straw lignin. Miscanthus lignin is an exception from the grass lignins and possesses a significantly higher antioxidant capacity. All lignins possess a good antioxidant capacity and thus are promising candidates for various applications, e. g. as additives in food packaging or for biomedical purposes.


Asunto(s)
Antioxidantes , Lignina , Antioxidantes/farmacología , Antioxidantes/química , Lignina/química , Extractos Vegetales/química , Poaceae
14.
Int J Biol Macromol ; 230: 123245, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36639080

RESUMEN

Spent coffee ground (SCG) is a representative type of biomass waste with huge annual output. To better develop high value applications of SCG, in this study, the lignin-polysaccharide complex (LPC) was isolated from SCG by applying effective ball milling and the subsequent solvent extraction of 96 % 1, 4-dioxane aqueous solution. In addition to the comprehensive analyses of the obtained LPC regarding its chemical composition, surface morphology, molecular weight distribution, characteristic functional groups, surface chemical linkages, and thermal stability, its potentials in radical scavenging and UV shielding had been emphatically investigated. As revealed from the results, a proper duration (e.g., 4 h) of UV irradiation could evidently enhance the radical-scavenging capacity of LPC, ascribed to the increasing number of antioxidant groups. Moreover, the LPC-containing composite sunscreens also exhibited strengthened UV resistance after UV irradiation, which may benefit from the UV-induced conjugated structures and the π-π stacking of aromatic rings from both LPC and the active ingredients in commercial sunscreen. Therefore, LPC is highly promising to be exploited for the development of novel antioxidants and UV-shielding products, by virtue of its characteristic chemical structure and potential synergistic effect with other active ingredients from the composite.


Asunto(s)
Antioxidantes , Lignina , Antioxidantes/química , Lignina/química , Café/química , Polisacáridos/química , Rayos Ultravioleta , Protectores Solares/farmacología
15.
Environ Technol ; 44(3): 416-430, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34433389

RESUMEN

This work reports the preparation of nano lignin-rich fraction material via green technology from the holistic use of lignocellulosic biomass bamboo. The bamboo is first chemically treated, followed by acid precipitation to extract bamboo-derived macro lignin-rich fraction material. The nano lignin-rich fraction material was then prepared via ultrasonication technique from the extracted bamboo-derived macro lignin-rich fraction material. The confirmation of the distinct lignin functional groups in the extracted lignin-rich fractions has been done by FTIR. Surface morphology by FESEM and TEM revealed spherical nano-lignin-rich fraction materials from extracted bamboo-derived macro lignin-rich fraction materials. DPPH assays indicated that both the obtained fractions depict beneficial antioxidant characteristics. They were found to be effective in terms of their antibacterial activity against both gram-positive bacteria Staphylococcus aureus (S.aureus) and gram-negative bacteria Escherichia coli (E.coli), using the disc diffusion method. These fractions have UV blocking property, and nano-lignin-rich fraction material acts as a more potential UV blocking agent than others. Thus, the nano-lignin-rich fraction material has great potential as a high antioxidant, antibacterial, and UV blocking agent useful in biomedical applications.Highlights Extraction of macro-lignin rich fraction material using chemical treatment of lignocellulosic biomass bamboo via refluxing followed by acid precipitation.Preparation of nano-lignin rich fraction material from extracted bamboo-derived macro-lignin rich fraction material via ultrasonication technique as a green technology.Structural and surface morphology of the extracted macro-lignin & nano lignin-rich fraction materials have been analyzed by XRD, FTIR, EDX, SEM and TEM.The macro lignin & nano lignin-rich fraction materials showed good antioxidant, antibacterial activity and UV-blocking properties, but the nano-lignin rich fraction material exhibited more efficient properties.


Asunto(s)
Antioxidantes , Lignina , Antioxidantes/farmacología , Lignina/química , Extractos Vegetales/farmacología , Extractos Vegetales/química , Antibacterianos/farmacología , Antibacterianos/química , Escherichia coli
16.
Int J Phytoremediation ; 25(10): 1359-1370, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36576064

RESUMEN

Ligno-cellulosic biomasses had been recognized for their potential use to produce chemicals and biomaterials. The current study focused on the use of a new cellulosic Robinia Pseudoacacia fiber and extracted lignin as adsorbents for methylene blue (a cationic dye). The biomaterials were analyzed using FT-IR spectroscopy, SEM, XRD, and TGA-DTA techniques. The surface of Robinia fibers was rough and porous. The crystallinity index (CrI) value for Robinia fibers was found to be 32%. The ability of the studied samples to remove methylene blue from water was assessed under the variation of time, pH, dye concentration, temperature, and NaCl concentration. The maximum adsorption capacity of methylene blue reached 191 mg/g for Robinia fibers and it achieved 22 mg/g for the extracted lignin (T = 20 °C, pH = 6, and time = 90 min). The adsorption data complied with the pseudo second-order kinetic model and both Langmuir and Freundlich isotherms. Based on these findings, the process suggested the occurrence of many physicochemical interactions between methylene blue molecules and the studied biomaterials. The adsorption mechanism was exothermic, non-spontaneous, and it was described by the decrease of the disorder. Adsorption results proved that Robinia fiber was an attractive candidate for the removal of cationic dyes from water.


A low-cost and abundant Robinia Pseudoacacia fiber and its extracted lignin are characterized and further studied as adsorbents for cationic dyes under the change of the experimental conditions.


Asunto(s)
Robinia , Contaminantes Químicos del Agua , Agua , Lignina/química , Azul de Metileno/análisis , Azul de Metileno/química , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/química , Concentración de Iones de Hidrógeno , Biodegradación Ambiental , Colorantes/química , Adsorción , Cinética
17.
Environ Technol ; 44(5): 695-707, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34617872

RESUMEN

In order to obtain a lignin-based adsorbent with low cost, simple operation and no further modification, a calcium lignin adsorbent was prepared from chemical mechanical pulping (CMP) waste liquor by directly calcification from lime. The calcium lignin was characterized by BET, SEM, TEM, FT-IR and solid-state NMR analyses. The results showed that the molecular structure of the calcium lignin particles did not change when compared to sodium lignin, the formation mechanism of calcium lignin was revealed. The initial COD and lignin contents of CMP waste liquid were 54858 mg/L and 24.39 g/L, the conversion rate of lignin can reach 71.36% when was deal with lime. Thus, most of the lignin resources in the waste liquid were recovered. The middle-stage wastewater (MSWW) of pulping and papermaking was dealt with calcium lignin, the COD removal rate was up to 85.83%. The adsorption isotherms and kinetics were well fitted by the Langmuir model and pseudo-second-order kinetic model, respectively. Lime was regenerated from the used calcium lignin with high-temperature calcination, the conversion rate of calcium ions can reach 83.56%. Overall, the calcium lignin prepared by the one-step method exhibited great potential for effectively removing COD from middle-stage wastewater.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Calcio , Lignina/química , Espectroscopía Infrarroja por Transformada de Fourier , Adsorción , Cinética , Concentración de Iones de Hidrógeno
18.
Photochem Photobiol ; 99(2): 706-715, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35929341

RESUMEN

Given the current grave problems with antibiotic resistance, the discovery of novel, unconventional antibacterial drugs is not just important but also urgent. In this contribution, we report on the synthesis and testing of several composite nanomaterials that may find applications as therapeutic drugs or surface disinfectants. These materials are based on magnetic nanostructures coated with lignin, for example, lignin@FeCo. The magnetic properties of these nanocomposites facilitate removal or localization, whereas the lignin shell provides biocompatibility. These nanomaterials are mild antibacterials in the absence of light, but when illuminated become powerful antibacterial agents with typically ≥6 log units of bacterial reduction in 1-5 min of irradiation. These materials are strongly absorbing, including in the very useful NIR biological window, which we illustrate using 810 nm LED irradiation. We also show that in the short time required for antibacterial action, thermal changes are very small (≤5°C). Further, biocompatibility tests using fibroblasts show very limited cell damage and no enhanced adverse effect during 810 nm NIR illumination. As a surface coating for the active material, lignin provides a "trojan horse" strategy to facilitate the antibacterial action.


Asunto(s)
Nanopartículas de Magnetita , Nanocompuestos , Nanopartículas , Lignina/química , Antibacterianos/farmacología , Antibacterianos/química , Nanopartículas/química , Nanocompuestos/química
19.
Methods Mol Biol ; 2566: 243-259, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36152257

RESUMEN

Autofluorescence of plant tissues can be used as a label-free method to detect a range of phenolic-based cell wall components including lignin, suberin, and ferulate using widefield or confocal fluorescence microscopy. Likewise, fluorescently labeled antibodies can be used to localize specific carbohydrate molecules including arabinoxylan, ß-1,4 galactan, glucomannan, glucuronoxylan, pectins, and xyloglucan. When combined, these two methods allow detailed study of topochemistry in different plant tissues for phenotyping of mutant varieties and plant biology studies. This article describes the protocols for fluorescent detection and imaging of molecules in plant cell walls using autofluorescence and immunofluorescence.


Asunto(s)
Pared Celular , Lignina , Pared Celular/química , Galactanos , Lignina/química , Microscopía Fluorescente/métodos , Pectinas/análisis
20.
Carbohydr Polym ; 298: 120112, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36241286

RESUMEN

In this study, a series of pretreatment methods (pectin extraction) were employed to prepare cellulose nanofibrils (CNFs) with different pectin composition and contents from ramie fibers. The comprehensive effects of residual pectin on the final properties of CNFs were investigated. The residual pectin did not have a significant effect on the size distribution of the obtained CNFs. While the presence of pectin led to higher zeta potential value, improved dispersion stability and enhanced storage modulus of the CNF dispersion, with the sodium carbonate extraction method showing the greatest impact. The possible mechanism for enhanced dispersion stability of CNFs is the formation of self-assembled hierarchical pectin-hemicellulose/lignin-cellulose nanostructures, offering abundant electrostatic repulsion and steric hindrance between the nanoparticles. This work provides guidelines for the tailored production of CNFs to meet the requirements for different applications.


Asunto(s)
Boehmeria , Nanofibras , Celulosa/química , Lignina/química , Nanofibras/química , Pectinas
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