Decomposition Of Hemicellulose Research Articles

Genomic evidence for the widespread presence of GH45 cellulases among soil invertebrates.

Lignocellulose is a major component of vascular plant biomass. Its decomposition is crucial for the terrestrial carbon cycle. Microorganisms are considered primary decomposers, but evidence increases that some invertebrates may also decompose lignocellulose. We investigated the taxonomic distribution and evolutionary origins of GH45 hydrolases, important enzymes for the decomposition of cellulose and hemicellulose, in a collection of soil invertebrate genomes. We found that these genes are common in springtails and oribatid mites. Phylogenetic analysis revealed that cellulase genes were acquired early in the evolutionary history of these groups. Domain architectures and predicted 3D enzyme structures indicate that these cellulases are functional. Patterns of presence and absence of these genes across different lineages prompt further investigation into their evolutionary and ecological benefits. The ubiquity of cellulase genes suggests that soil invertebrates may play a role in lignocellulose decomposition, independently or in synergy with microorganisms. Understanding the ecological and evolutionary implications might be crucial for understanding soil food webs and the carbon cycle.

Kinetic, products and shrinkage for the pyrolysis of flax fibers

Biomass pyrolysis is a thermochemical process used for renewable products and energies. However, there are still issues that need to be addressed for process modeling and optimization. This study focuses on the relationship between heating rate, shrinkage, and products from flax fibers using thermogravimetric analysis (TGA), microscopic observation, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). TGA confirms sequential evaporation of water then decomposition of hemicellulose, cellulose, and lignin. Observations from the micro-reactor show that flax fibers undergo shrinkage within the temperature range of 335–370 ∘C, depending on the heating rate. Pyrolysis products were analyzed using Py-GC/MS at four different final temperatures from 350 to 500 ∘C, revealing the presence of anhydrosugars, furans, ketones, phenols, esters, alcohols, aldehydes, and acids. The results indicate a correlation between temperature and the increase in furans and ketones. The analysis suggests that furans and ketones are associated with shrinkage.

Maintaining the native gut microbiota of bharal (Pseudois nayaur) is crucial in ex situ conservation.

As wildlife protection continue to strengthen, research on the gut microbiota of wildlife is increasing. Carrying out conservation and research on endangered species in the Qinghai Tibet Plateau plays an important role in global biodiversity conservation. This study utilized 16S rRNA sequencing of fecal samples to investigate the composition, function, and changes of the gut microbiota of bharal in different environments, seasons, and genders. The results showed that Firmicutes and Bacteroidota were the dominant phyla and UCG-005, Bacteroides, UCG-010 were the dominant genera of bharal. In the wild, the abundance of Firmicutes increased which was conducive to the decomposition and utilization of cellulose, hemicellulose, and carbohydrate. Due to the variety of food types and nutrition in different seasons, the composition and function of gut microbiota were obviously different between genders. Compared with zoo, higher alpha diversity, a more complex gut microbiota network structure, and stronger metabolic function were conducive bharal to adapting to the wild environment. In the zoo, captive bharals were fed foods rich in high fat and protein, which increased the abundance of Bacteroidota and reduced the alpha diversity of gut microbiota. A fixed diet unified the gut microbiota between genders of bharal. It is very important to pay attention to the impact of captive environments and maintain the native gut microbiota of wildlife.

Drying Shrinkage and Mechanical Strength of Cementitious Composites with Alkali-Treated Makino Bamboo Fibers

ABSTRACT Alkali-treated bamboo fibers (AFs) treated with different NaOH concentrations (5 and 10%) and treatment times (1, 12, and 24 h) were used as fillers to fabricate cementitious composites with AFs (CAFs) in the present study. The results demonstrated that alkali treatment caused the partial decomposition of hemicellulose and lignin and an increase in the surface roughness of bamboo fibers. Additionally, the amounts of calcium hydroxide in alkali-treated CAFs were higher than in untreated CAFs, and they increased with increasing NaOH concentration and treatment time. For drying shrinkage (DS) under 75% relative humidity (RH), the DS values of the CAFs significantly decreased after adding AFs compared to the DS values of untreated CAFs. Compared to untreated CAFs, the density of the 5% and 10% NaOH-treated CAFs with longer treatment times decreased by 2.9% and 5.1%, respectively. Furthermore, the tensile strength of all alkali-treated CAFs exhibited no significant differences when compared with that of untreated CAFs, while the modulus of rupture and compressive strength were significantly decreased by NaOH treatment. These results indicated that the AFs significantly improved the drying shrinkage of the CAFs and hydration retardation effect of cement pastes, while the density and mechanical strength of the CAFs decreased.

Interaction among lignocellulosic biomass components in thermochemical processes

This research aims to evaluate the thermal behavior of main components of biomass (hemicellulose, cellulose and lignin) in order to identify their synergistic effect in thermochemical processes. These components were isolated from sugarcane bagasse and straw using different chemical treatments and their chemical and physical-chemical characterizations were performed. Results showed that chemical treatments were adequate for cellulose and lignin isolation, although it was verified that more adequate methodologies must be sought for hemicellulose isolation. The thermogravimetric analysis of each sample and their mixtures in inert (N2) and oxidant (synthetic air) atmospheres allowed investigating the synergism among the components. It was observed that the synergistic effect was more pronounced in DTG curves in an oxidizing atmosphere. There was a weak interaction effect between cellulose and hemicellulose, but hemicellulose allowed reducing cellulose decomposition rate. Moreover, the mixture between hemicellulose and lignin showed a synergistic effect on lignin, which promoted an increase in hemicellulose decomposition rate, while hemicellulose anticipated the main event of lignin decomposition in an oxidizing atmosphere. It was found that lignin had a positive effect on cellulose decomposition in an oxidizing atmosphere, thus inhibiting its decomposition, while cellulose promoted an increase in lignin decomposition rate in its final event. Ultimately, results for the synergistic effect allowed detecting other components besides isolated elements in the biomass structure in smaller amounts, which nevertheless affect the behavior of its thermal decomposition.

Synergistic effects of the mixing factor on the kinetics and products obtained by co-pyrolysis of Rosa rubiginosa rosehip seed and husk wastes

The aim of this work was to study the potential synergistic effects of the mixing factor on the kinetics parameters and products obtained through co-pyrolysis of two wastes from Rosa rubiginosa rosehip, and further co-gasification with CO2 of the remaining biochar. Thermogravimetric analysis showed that 6 different processes occur by slow pyrolysis (heating rates of 5, 10, and 20 °C/min), associated with the decomposition of hemicelluloses, cellulose, lignin, and CaCO3 from the ashes. Isoconversional methods determined activation energies of 84.68–223.42, 230.11–270.85, 187.58–303.37, and 400.11–421.71 kJ/mol for hemicellulose, cellulose, lignin, and CaCO3 decomposition, respectively. In most cases, the activation energy from co-pyrolysis was higher for the blends than for the pure wastes, which means that the blends are less reactive to pyrolysis. Gas and tar analyses showed that the blend with 75 % husk waste and 25 % seed waste produced the most hydrogen (5.639 mmol/g biomass), while the blend with 25 % husk waste and 75 % seed waste produced the most carbon monoxide (3.642 mmol/g biomass). The biochar produced by the blends and pure wastes were thermally treated with CO2 to compare reactivity to gasification. It was concluded that the addition of husk waste to the blend increases the reactivity of the biochar obtained, mainly due to its higher ash content.

Devolatilization characteristics of a bio-residue (potato stems) with high contents of alkali metals and non-structural components – Influences of the washing pretreatment severity

A bio-residue (potato stems), rich in alkali metals and non-structural components, is subjected to hot (353 K) or acidic (0.1 mol/L hydrochloric acid) water washing. The acidic pretreatment is more effective for the demineralization, with alkalis reduced by 99 (powders) or 90 (particles) %, corresponding to organic matter dissolution around 35 or 17 wt%, respectively. The latter figures remain approximately the same for hot water washing (38 and 19 wt%) but alkalis are reduced only by 78 or 64 %. The leachate properties are significantly dependent on the solvent type and the residue granulometry, as indicated by thermogravimetric and SEM-EDX analysis. Washed bio-residues decompose at temperatures and with rates progressively increasing as the pretreatment becomes more severe (fine granulometry and acidic water washing). Multi-step global kinetics, previously developed for the untreated material and properly revisited to incorporate washing effects, reveals trends with important compositional changes. Despite starch dissolution, volatile product yields for the absolute peak rate zone increase by about 40–65 %, testifying augmented cellulose contents. The pectin compounds are almost eliminated, to the advantage of the shoulder rate zone, representing hemicellulose decomposition, with an increase in the volatile product yields around 22–78 %.

Effects of different heat treatment media on odorous constituents, chemical decomposition and mechanical properties of two hardwoods.

With China's increasing dependence on foreign wood, African wood has gradually become a potential imported species, but its use is seriously affected by problems such as unpleasant odors. In this study, we investigate the effect of heat treatment medium on odor-causing VOCs, decomposition of structural polymers, Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) of hardwood. Samples of "Afrormosia" and "Newtonia" wood were heated under air and palm oil for two hours at 160 °C, 180 °C, and 200 °C, respectively. Then, the nature of the odor of each VOC emitted by the wood before and after heat treatment was identified using the GCMS method. The decomposition of hemicelluloses, cellulose and lignin in wood samples was examined using a ThermoGravimetric Analyzer coupled to Fourier Transform InfraRed spectrometry (TGA-FTIR). The 3-point bending test was used to evaluate MOR and MOE. The results indicate that the main VOCs responsible for unpleasant smells are acetic acid and hexanal; the reduction in hexanal emissions after heat treatment is mainly due to the treatment temperature, while the reduction in acetic acid emissions depends on the heat treatment medium and is due to the chemical interactions between palm oil and acetic acid; thus, the heat treatment under palm oil reduces the percentage area of VOCs with unpleasant odors in Afrormosia and Newtonia wood better than the heat treatment under air. Based on TGA-3D FTIR analysis and mechanical results, the reduction in MOR is greater in heat treatment under air because the said treatment induces a greater loss of woody matter, which was characterized by higher H2O and CO emissions during heat treatment of wood under palm oil than during heat treatment of wood under air. On the other hand, palm oil more than air, promotes lignin deacetylation, which is characterized by the fact that the 1050 cm-1 wavelength peak was far higher in samples treated with palm oil than in those treated under air; and this might explain why heat treatment under palm oil reduces MOE more than heat treatment under air.

Pyrolysis interaction of cellulose, hemicellulose and lignin studied by TG-DSC-MS

The pyrolysis kinetics, heat endothermic and exothermic characteristics and gases formation of cellulose, hemicellulose, lignin and their mixtures were investigated by TG-DSC-MS to understand the interaction of biomass three components and its influence on the pyrolysis gas products. It was found that there were complex interactions among three components, and the activation energy of mixtures pyrolysis was mainly divided into two stages. During the pyrolysis process, cellulose could promote the decomposition of lignin and hemicellulose, while hemicelluloses might restrain the decomposition of cellulose and lignin. Furthermore, lignin promoted the decomposition of hemicelluloses but inhibited the decomposition of cellulose. The interactions also had a great influence on the gas products. The gas products generated during pyrolysis of three components were mainly H2, CO, H2O and CO2. Hemicellulose and lignin promote H2 release, while cellulose and lignin inhibit the release of H2O and CO2, and all three components restrain the release of CO. The effect of hemicellulose on H2O and CO2 would depend on pyrolysis temperature of 325 °C.

Transcriptome analysis reveals the mechanism of delayed softening of ‘France’ prune (Prunus domestica L.) during storage at near-freezing temperature

Rapid loss of firmness of ‘France’ prune after harvest limits the commercial potential of the fruit. Therefore, the present study aimed to explore the potential mechanism by which near-freezing temperature (NFT) maintains fruit quality and delays the softening of ‘France’ prune. We found NFT maintained higher fruit firmness (91.34 %), delayed the decomposition of cellulose (53.87 %) and hemicellulose (41.41 %), and inhibited the activity of softening-related enzymes compared with the control group. RNA-sequencing data showed that 4984 differentially expressed genes (DEGs) were detected in the control group (CK30)-vs-NFT group (B30) comparison. These DEGs are mainly involved in plant hormone signal transduction, secondary metabolite biosynthesis, galactose metabolism, and the pentose-glucuronate interconversion pathway. By screening and identifying DEGs, we found that the PG, PME, CEL, ACS, PER, UGT, and transcription factor (TF) genes (NAC089, ERF026, and NAC083) may be involved in the softening of ‘France’ prune. In conclusion, NFT delays the softening of ‘France’ prune likely by regulating the expression of related genes and metabolic pathways. These findings provide a theoretical basis for understanding the mechanism of NFT-mediated delay of ‘France’ prune fruit softening.

Successional action of Bacteroidota and Firmicutes in decomposing straw polymers in a paddy soil

BackgroundDecomposition of plant biomass is vital for carbon cycling in terrestrial ecosystems. In waterlogged soils including paddy fields and natural wetlands, plant biomass degradation generates the largest natural source of global methane emission. However, the intricate process of plant biomass degradation by diverse soil microorganisms remains poorly characterized. Here we report a chemical and metagenomic investigation into the mechanism of straw decomposition in a paddy soil.ResultsThe chemical analysis of 16-day soil microcosm incubation revealed that straw decomposition could be divided into two stages based on the dynamics of methane, short chain fatty acids, dissolved organic carbon and monosaccharides. Metagenomic analysis revealed that the relative abundance of glucoside hydrolase (GH) encoding genes for cellulose decomposition increased rapidly during the initial stage (3–7 days), while genes involved in hemicellulose decomposition increased in the later stage (7–16 days). The increase of cellulose GH genes in initial stage was derived mainly from Firmicutes while Bacteroidota contributed mostly to the later stage increase of hemicellulose GH genes. Flagella assembly genes were prevalent in Firmicutes but scarce in Bacteroidota. Wood–Ljungdahl pathway (WLP) was present in Firmicutes but not detected in Bacteroidota. Overall, Bacteroidota contained the largest proportion of total GHs and the highest number of carbohydrate active enzymes gene clusters in our paddy soil metagenomes. The strong capacity of the Bacteroidota phylum to degrade straw polymers was specifically attributed to Bacteroidales and Chitinophagales orders, the latter has not been previously recognized.ConclusionsThis study revealed a collaborating sequential contribution of microbial taxa and functional genes in the decomposition of straw residues in a paddy soil. Firmicutes with the property of mobility, WLP and cellulose decomposition could be mostly involved in the initial breakdown of straw polymers, while Bacteroidota became abundant and possibly responsible for the decomposition of hemicellulosic polymers during the later stage.

Assessment of biochar developed via torrefaction of food waste as feedstock for steam gasification to produce hydrogen rich gas

In this study, the torrefaction of food waste was carried out using a thermogravimetric analyzer (TGA) to produce biochar and assess its suitability as feedstock for steam gasification. Torrefaction was conducted at temperature from 230 to 290 °C and the heating rate from 10 °C/min to 30 °C/min. Subsequently, the detailed characterization was conducted using proximate, elemental, lignocellulosic, nutrient analysis, and TGA analysis. The proximate and elemental analysis showed that biochar had the highest fixed and elemental carbon at the highest temperature (290 °C) and lowest heating rate (10 °C/min). Similarly, TGA indicated that increase in temperature increased the mass loss, however, increase in heating rate did not yield much change in mass loss. Additionally, lignocellulosic and nutrient analysis showed that lignin fraction increased (up to 80%) with increases in severity of the torrefaction due to significant decomposition of hemicellulose, cellulose, starch, proteins, and lipids. Thereafter, the kinetic parameters (activation energy, pre-exponential factor) of torrefaction of food waste were determined using the two-step decomposition model which showed a good fit with experimental data. Finally, the biochar developed was used for energy production using steam gasification which produced syngas with maximum yield of 3.75 m3/Kg and having hydrogen fraction of around 65% at the optimal conditions (temperature: 290 °C, heating rate: 10 °C/min).Graphical

Improved bio-oil yield from thermo-catalytic pyrolysis of Citrus limetta waste over pumice: Determination of kinetic parameters using Kissinger method

The focus of this research is on thermo-catalytic conversion of Citrus limetta waste, with and without pumice, using thermo gravimetric analysis and a pyrolysis chamber. TG/DTG results demonstrated weight reduction occurring in four stages i.e., evaporation of water, degradation of hemicellulose, decomposition of cellulose and lignin. Activation energy (Ea) calculated using Kissinger method for non-catalytic decomposition of hemicellulose, cellulose, and lignin was found as 99.76, 157.96 and 174.59 kJ mol−1 and for catalyzed reactions as 83.14, 91.45 and 149.65 kJ mol−1respectively. Thermal degradation of Citrus limetta waste produced 30 % oil in the range of C2–C24, while catalytic pyrolysis produced more than 45 % pyrolysis oil with a wide range of components from C4 to C32 which shows, that pumice has not only decreased the activation energy of the pyrolysis reaction but improved the quality of bio-oil making it suitable for energy on upgradation.

Linking microbial carbon‐degrading potential to organic carbon sequestration in fertilized soils: Insights from metagenomics

AbstractThe capacity of soils to store organic carbon (SOC) is vital for agricultural productivity. Soil microorganisms exert a critical role in carbon (C) flow and potentially influence C balance through the decomposition of plant and microbial dead biomass. However, the connection between the microbial degradation potential of plant‐derived and microbial‐derived C and soil organic carbon sequestration (SOCSR) under organic and inorganic nitrogen (N) fertilization treatments remains largely unexplored using metagenomics. In this study, metagenomics was used to investigate the effects of 4 years inorganic (N1: 250 kg N ha−1 yr−1 and N3: 450 kg N ha−1 yr−1) and organic N (O1: N1 + 11,250 kg ha−1 yr−1 sheep manure and O3: N1 + 18,750 kg ha−1 yr−1 sheep manure) fertilizer application on plant biomass decomposition genes, microbial biomass decomposition genes, and microbial properties related to different sources of C decomposition (species composition and diversity). Furthermore, the study explored the relationship between organic matter decomposition genes, microorganisms, and SOCSR. The results revealed that compared with N1 treatment, the increased application of inorganic N fertilizer (N3) significantly enhanced the abundance of genes related to plant and microbial biomass decomposition and microbial diversity involved in SOC decomposition, resulting in reduced SOC content. Conversely, the increased application of organic N fertilizer (O1 and O3) had a minor effect on the abundance of genes related to different sources of C decomposition and C decomposing microbial diversity, but reduced microbial entropy (the ratio of microbial biomass carbon to SOC) and increased SOC content. The random forest model highlighted that plant biomass decomposition genes and bacterial community composition were important factors affecting SOCSR. The Mantel test also indicated that the genes involved in the decomposition of lignin, cellulose, and hemicellulose were closely related to SOCSR. These findings highlighted that increased inorganic N fertilizers greatly enhanced the microbial capacity for SOC decomposition, resulting in reduced SOC accumulation. While the increased application of organic N fertilizer increased SOC stability and reduced the mineralization potential of SOC, contributing to SOCSR. Overall, these findings provide a greater understanding of the relationship between soil C turnover and microbial C‐degrading potential under short‐term fertilization. And in a long time, they may have important implications for global strategies aimed at increasing SOCSR to restore fertility and facilitate sustainable agricultural development.

Establishment of patterns in the thermal modification of dry pine wood

One of the methods of ensuring the durability of dry wood during operation is its thermal modification, which inhibits the life processes of the fungus of the Ceratostomaceae family and leads to a change in its structure and properties. Therefore, the object of research was thermally modified dry pine wood affected by a fungus of the Ceratostomaceae family. Physicochemical studies of changes in the structure of thermally modified dry pine wood showed that the samples have absorption spectra that are characterized by fluctuations of the glucopyranose ring of cellulose and are an indicator of the beginning of destructive processes. At the same time, the data of thermogravimetric analysis show the processes of water loss and decomposition of hemicellulose, cellulose, and lignin, and burning of coke residue. Bending and compressive strength of thermally modified dry pine wood shows that as the wood dries, the strength limit decreases depending on the degree of fungus damage. Namely, with an area of biological damage within 10 %, the strength limit is reduced by more than 1.2 times when modified at 200 °С/3 hours, by more than 1.9 times at 200 °С/6 hours. With an increase in the degree of fungal damage to 30÷50 %, the strength limit decreases by more than 1.6 times when modified at 200 °С/3 hours, by more than 2.1 at 200 °С/6 hours. And when affected by a fungus in the range of 80÷100 %, the wood becomes softer, more plastic, while the bending strength is reduced by 1.7 times, and the compressive strength by 1.16 times. Thermal modification of dry pine wood at 200 °С for 3 hours reduces the level of water absorption by more than 1.5 times, and for 6 hours ‒ by more than 1.7 times. The practical importance is that the results of determining changes in the structure and properties of thermally modified dry pine wood make it possible to establish the scope and conditions of its application

Stepwise failure behavior of thermal-treated bamboo under uniaxial tensile load

In this paper, the tensile behavior, including the tensile strength, the stress-strain curve and the crack propagation process of Moso bamboo (Phyllostachys pubescens) before and after heat treatment was studied. The microstructure and chemical composition analysis was conducted to discover the mechanism underneath the mechanical behavior. The tensile strength decreases with the increasing treating temperature. The chemical analysis indicated that the decomposition of cellulose and hemicellulose is responsible for the decrease of tensile strength. The unique composite structure of bamboo makes it shows stepwise failure behavior under uniaxial tensile load. During tension, the fiber sheaths dispersing in the ground parenchymatous break dispersively, making the strain-stress curve fluctuate like stairs. And the fluctuations become more obvious with the increase of treating temperature. The microstructure analysis indicates that the structural change of the fiber cell wall is responsible for the more fluctuant strain-stress curve.

Study on the effect of different solvent pretreatment on the pyrolysis characteristics of tobacco

Solvent pretreatment can remove some components in biomass and change the distribution of its pyrolytic products. Combined with the physicochemical analysis of tobacco before and after solvent pretreatment, the pyrolysis characteristics of tobacco and the changes of pyrolysis oil components after the removal of some components of tobacco by deionized water, 75% ethanol, and 3% lactic acid were evaluated by thermogravimetry (TG) and high-temperature pyrolysis experiments. The results showed that the O/C atomic ratio of tobacco decreased after solvent pretreatment, and the high concentration of ethanol had a huge effect on the intensity of the peaks associated with aromatic and pyranic rings. TG analysis showed that the pyrolysis of pretreated tobacco was mainly characterized by the thermal decomposition of cellulose and hemicellulose. For ethanol and lactic acid-washed samples, the weight loss in the last stage decreased and the amount of the char residues increased, with the highest of 22.7% for the lactic acid-washed sample. Gas chromatography-mass spectrometry analysis of high-temperature pyrolysis oil showed that water pretreatment could effectively reduce the production of aromatics and cresols, while ethanol was able to elute chlorogenic acid, a precursor of hydroquinone. Lactic acid pretreatment increased the relative content of long-chain hydrocarbons and acids, causing the relative peak area percentages of n-hexadecanoic acid to increase from 1.8% to 8.91% compared with the raw sample of tobacco. In addition, organic solvent pretreatment promoted the formation of ketones in the pyrolysis oil and also inhibited the formation of substituted pyridines at the C-3 position on the pyridine ring.

Analysis of the Fuel Properties of the Seed Shell of the Neem Plant (Azadirachta indica)

The energetic potential of the seed shell of the Neem plant (Azadirachta indica) was investigated using proximate analysis, Higher Heating Value (HHV), thermal analysis (TG-DTG and DSC) in inert and oxidative atmospheres, and X-ray fluorescence (XRF). The results of ash (3.80% ± 0.44), volatile matter (81.76% ± 1.30), fixed carbon (14.44% ± 1.74), and estimated HHV (18.791 MJ/kg: average value) are compatible with other biomasses already used as fuels in the bioenergy industry. Thermograms showed three main degradation events in synthetic air and two in nitrogen, attributed to the moisture, release of volatile materials, and decomposition of hemicellulose, cellulose, and lignin. The elements positively detected by the XRF were Ca, K, S, P, Fe, Ti, Zn, Rb, and Sr.

One-pot cogeneration of phenol-rich bio-oil, hydrogen-rich gas and solid carbon degradation material from reed

A newly developed two-step catalytic pyrolysis process (TSCP) based on poly-generation technology is proposed to convert reed straw (RS) into phenol-rich bio-oil, hydrogen-rich gas, and solid carbon degradation material over iron-loaded activated carbon. The effects of the first step pyrolysis temperature (T1) and catalyst composition on the product distribution and target product selectivity were investigated. When T1 was 350 °C and 10% Fe/AC catalyst was selected, the concentration of phenolic compounds and H2 peaked at 63.87 area% and 63.29 vol%, respectively. The iron-loaded activated carbon catalysts promoted the decarboxylation and decarbonylation reactions of cellulose and hemicellulose decomposition products, as well as the demethylation and demethoxylation reactions of lignin for the selective production of phenolic compounds and hydrogen gas. In addition, 94.7% quinclorac (10 mg/L) removal was achieved with 0.2 g/L 10% Fe/AC catalyst-doped pyrolysis carbon and 2 mM PMS within 90 min. This study could realize the high-value comprehensive utilization of reed and provide a reference for the full quantitative utilization of other agricultural and forestry wastes.

Deep Straw Burial Accelerates Straw Decomposition and Improves Soil Water Repellency

The continuous input, slow decomposition, and retention of straw can impede tillage and crop growth, and the decomposition process of the straw in soil is affected by its composition and the method of application. Experimental Station of Jilin Agricultural University, Changchun City, Jilin Province. The soil type was Argiudolls, the experimental field area was 30 m2, and the maize was planted continuously for 12 years without returning the straw to the field. There were four treatments: (1) control (CK), 10 g of straw was placed on the surface of a nylon mesh bag, and the nylon mesh bag was separated from the soil by polyethylene film without contacting with the soil; (2) straw mulching (CM), a nylon mesh bag with 10 g of straw was placed on the soil surface; (3) straw burying (CD), a nylon mesh bag with 10 g of straw was buried at a depth of 40 cm from the soil surface; (4) straw burying (CE), a nylon mesh bag with 40 cm of soil depth. Fifteen micro-zones were set up with a micro-zone area of 1 m2 and each micro-zone consisted of four treatments randomly grouped in three replicates per treatment. The on-site nylon bag burying trial started on 20 April 2021 and ended on 15 April 2022. Nylon bag and soil samples were collected on days 0, 30, 90, 180, 270, and 360. SOC, TN, straw component decomposition, and water droplet-soil contact angle were determined. Our results showed that the CE treatment increased soil organic carbon (SOC) and total nitrogen (TN) content compared to the CM and CD treatments. Compared with CK, straw decomposition rates increased by 13.3%, 30.8%, and 22.3% in the CM, CD, and CE treatments, respectively. Lignin decomposition rates increased by 7.8%, 27.3%, and 16.2%; cellulose decomposition rates increased by 14.6%, 35.4%, and 27.3%; and hemicellulose decomposition rates increased by 17.2%, 31.7% and 23.7% in the CD treatment, respectively. Compared with CK, the contact angle of droplets in the CD treatment was statistically significantly increased by 91.5% when the droplets remained on the soil surface for 5 s. The rate of decrease of droplet contact angle with time was statistically significantly decreased by 11.8%, and the penetration rate of droplets on the soil surface was slower. Overall, the CD treatment promoted straw decomposition and increased SWR compared to the CM and CE treatments. which are important attributes to enhance soil quality and improve soil structural stability.