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Abstract This study investigated the effect of rice straw biochar (RSB) on methane production during mainstream large-scale aerobic composting by using high-throughput sequencing and quantitative PCR. A 55-day large-scale aerobic composting experiment under cyclical forced-turning with aeration was conducted with control (CK) and experimental groups (BC), namely, without and with 10% RSB. The methanogen/methanotroph and microbial community of samples were analyzed by mcrA/pmoA and 16S rRNA/internal transcribed spacer region, respectively. The pore methane concentration had a positive relationship with mcrA and mcrA/pmoA. RSB accelerated methane production, which was reflected by an increase in mcrA. The diversity of bacteria and fungi increased by addition of RSB. Addition of RSB contributed to increasing the RAs of Methanobrevibacter and Methylobacterium. Methanobrevibacter was related to CH 4 production, and Methylobacterium related to CH 4 consumption through the metabolism of methyl material. Thus, the biochar has always increased the diversity of bacteria, including Methanobrevibacter and Methylobacterium. The optimal way to control CH 4 production is to reduce the number of mcrA/pmoA. Meanwhile, RSB contributed to methane production because of its small particle size in this study. The biochar particle size could be further optimized during large-scale aerobic composting process. Highlights • RSB increased the pore methane concentration during aerobic composting. • The mcrA / pmoA ratio is increased by addition of RSB. • RSB increased the richness of Methanobrevibacter and Methylobacterium. • Methanobrevibacter and Methylobacterium showed some correlation with total OM. [ABSTRACT FROM AUTHOR]

Highlights • HTC is an effective pretreatment for upgrading wheat straw. • 180–200 °C was the optimal treatment temperature range. • Above 200 °C, fixed carbon's activation energy decreased and reaction order = 0.1. • Leaching heavily impacted HTC160 and increased its activation energy. • Size of carbon microspheres gradually increased to 0.05–0.7 μm. Abstract In order to upgrade wheat straw, hydrothermal treatment at 160–240 °C was investigated. Meanwhile, the influence of temperature and leaching on the fuel's physicochemical and combustion properties were explored. A temperature of 180–220 °C was found to benefit the generation of hydrochar, with solid and energy yields of at least 57.3% and 69.9%, respectively. When temperature increased to 160 °C, hemicellulose was hydrolyzed and this led to the formation of carbon microspheres. The diameter of the carbon microspheres reached 0.05–0.7 μm. Hydrochars obtained at 160, 180, and 200 °C exhibited better combustion performance with higher comprehensive combustibility index value. While leaching heavily impacted the hydrochar derived at 160 °C and increased its activation energy (178 kJ/mol) above those obtained for treatment at 180 °C (164 kJ/mol) and 200 °C (169 kJ/mol). Overall, the recommended hydrothermal temperature for production of fuel from wheat straw is 180–200 °C. [ABSTRACT FROM AUTHOR]

Highlights • Pyrolysis characteristics differed for cow versus swine and chicken manures. • Alkali metals in manure promote the production of CO and CH 4. • Swine manure was identified as the most suitable for pyrolysis gasification. Abstract Livestock and poultry manures are important biomass resources that can produce biogas by pyrolysis. Manures contain varied components and alkali metal contents, which may increase the complexity of pyrolysis. The influence of alkali metals in raw manure on the pyrolysis characteristics and the properties of the released gaseous product between different livestock and poultry manures were compared by thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy and mass spectrometry (TGA–FTIR–MS). Five livestock and poultry manures showed different pyrolysis characteristics caused by the different components and alkali metal contents. The high alkali metal contents of swine manure (SM), broiler litter (BL), and layer chicken litter (LL), each of which showed one pyrolysis peak, catalytically reduced the activation energy; dairy manure (DM) and beef manure (BM) from cattle showed two overlapped pyrolysis peaks. The second release peaks of CH 4 for SM, BL, and LL were more intense than those of DM and BM, corresponding to the lower absorption intensities of C O and C O C/C C for SM, BL, and LL compared to those of DM and BM. The FTIR spectra of raw manures and biochars obtained at different final pyrolysis temperatures showed that the decreased absorptions of characteristic peaks in the biochars corresponded to the variations in the gaseous products. SM released the highest volume of H 2 and a high CH 4 yield, indicating that SM is more suitable for biogas production by pyrolysis gasification than other animal manures. [ABSTRACT FROM AUTHOR]

This study establishes an optimal mathematical modelling to rationally describe the dynamic changes and spatial distribution of temperature and oxygen concentration in the aerobic composting process using coupling mass-heat-momentum transfer based on the microbial mechanism. Two different conditional composting experiments, namely continuous aeration and intermittent aeration, were performed to verify the proposed model. The results show that the model accurately predicted the dynamic changes in temperature (case I: R 2  = 0.93, RMSE = 1.95 K; case II: R 2  = 0.86, RMSE = 4.69 K) and oxygen concentration (case I: R 2  = 0.90, RMSE = 1.26%; case II: R 2  = 0.75, RMSE = 2.93%) in the central point of compost substrates. It also systematically simulated fluctuations in oxygen concentration caused by boundary conditions and the spatial distribution of the actual temperature and oxygen concentration. The proposed model exhibits good applicability in simulating the actual working conditions of aerobic composting process. [ABSTRACT FROM AUTHOR]

A series of experiments was conducted to explore the effects of various water-washing solid-liquid ratios (1:50 and 1:10) and the stirring on wheat straw (WS) combustion properties. Comparing different solid-liquid ratio groups, a 16% increment in the higher heating value was obtained for 1:50 groups and only 5% for 1:10 groups relative to the raw material. Moreover, energy was lost 4–26 times greater in 1:10 groups than 1:50 groups. While water-washing reduced the comprehensive combustibility index by 14.89%–32.09%, the index values of washed WS were all higher than 2, indicating good combustion performance. The combustion activation energy of four washed WS were 175, 172, 186, and 176 kJ/mol, which were all higher than the 160 kJ/mol of WS. The fouling/slagging propensity of washed WS reduced to a lower possibility compared to medium of untreated WS. Overall, the recommended condition for washing WS before combustion is 1:50 ratio without stirring. [ABSTRACT FROM AUTHOR]

Mechanical fragmentation is an important pretreatment in the biomass biotransformation process. Mechanical fragmentation at the tissue scale significantly reduced the particle size of rice straw but did not significantly change its crystalline properties; the increase in the glucose yield was limited from 28.75% (95.55 mg/g substrate) to 35.29% (115.28 mg/g substrate). Mechanical fragmentation at the cellular scale destroyed the cell wall structure and reduced its crystalline properties. Thus, the glucose yield also showed a significant increase from 35.29% (115.28 mg/g substrate) to 81.71% (287.07 mg/g of substrate). The quantitative equations among the particle size, crystalline properties and glucose yield (mg/g substrate) are as follows: CrI = 44.14 × [1−exp(−0.03658 × D 50 )] and CP = (8.403 × logD 50 −24.1836)/(1−4.225/D 50 ^0.5); GY = −5.636CrI + 343.7 and GY = −14.62CP + 512.1; and GY = 97.218 + 247.5 × exp(−0.03824 × D 50 ). The quantitative correlations among the mechanical fragmentation scales and crystalline properties can determine the effect and mechanism of mechanical fragmentation on biomass and can further promote the construction of a cost-competitive biotransformation process for biomass. [ABSTRACT FROM AUTHOR]

Due to the widespread of adulteration of lipid in food and feed industry, the quality and safety of lipid are of public concern gradually. Firstly, the current article presents theory and mechanism of species identification of lipid by spectroscopic technique. Potential of near-infrared reflectance spectroscopy (NIR), Fourier transform infrared spectroscopy (FT-IR), and Fourier transform Raman spectroscopy (FT-Raman) applied to species identification of lipid were summarized. In addition, the relationship between lipid and spectroscopy as well as the recent advances of species identification of lipid were discussed. Research showed that FT-IR and FT-Raman spectroscopies possessed more efficient potential for species identification of lipid. Finally, prospects for future lipid detection and relative practical application, and combination of spectroscopy and other technique were further discussed. [ABSTRACT FROM AUTHOR]

There is a strong need for low-cost lignocellulosic composition simultaneous localization methodologies to benefit deeper understandings of crop stalk morphology. This study developed a robust quantitative safranin O-fast green staining-based optical microscopy imaging methodology for in-situ simultaneously generating digital profiles of lignin and cellulose in stalk tissues. Foreground extraction and dye residue removal of stained images were adapted. The ratios of normalized red (R), green (G), and blue (B) channel signal intensity, R/B and G/B, were defined as quantitative indicators of lignin and cellulose, respectively. The method was validated on model rice with known bioinformatics, and the results were consistent with those of fluorescence microscopy and immunogold labeling methods. The high-definition spatial in-situ simultaneous profiles of lignin and cellulose in alkali-treated maize stalk tissues and their variations were visualized. This low-cost, cell-scale method is expected to contribute to new discoveries in many areas of biomass refining and plant science. [Display omitted] [ABSTRACT FROM AUTHOR]

Knowledge of the compositional properties of crop residues feedstocks is important for process control and handling of co-products and waste from energy utilization. In this study, 1076 crop residues were collected from 326 sites across China. Chemical analysis of five organic chemical compositions, four proximate compositions, five ultimate compositions and eight mineral elements were conducted. Energy potentials of crop residues in China were quantified based on their compositional characterization. Results showed that the compositional characteristics of wheat straw, rice straw, corn stover, rape stalk and cotton stalk were shown to be significant different ( p < 0.05) and highly variable. The coefficients of variation were negatively correlated with the means of crop residues compositions. Principal component analysis reflected that the compositions could explain several variations and clustering rules of the five crop residues. The correlations among parameters could be briefly summarized as hemicelluloses/ash–cellulose/lignin/water soluble carbohydrates/crude protein/P, water soluble carbohydrates–crude protein, crude protein–N–P–Mg–Cu, volatile matter–ash–fixed carbon, C–H–O–N–S, P–K–Na–Ca and ash–C/H/O/K ( p < 0.01). The energy potentials of the five substrates were also significantly different ( p < 0.05). The higher heating values, theoretical ethanol yields, and theoretical biomethane yields of the crop residues were 12.97–18.58 MJ/kg, 336.69–658.25 g/kg, and 151.48–288.45 L/kg, respectively. [ABSTRACT FROM AUTHOR]

A new method for discriminating processed animal proteins (PAP) from different species based on their fat characteristics was established for the first time in this study. A total of 53 reliable PAP samples containing fish meal (FM), porcine, poultry, bovine, and ovine meat and bone meal (MBM) were collected, and 37 distinct fatty acids were statistically analyzed via gas chromatography. Principal component analysis and the partial least squares discriminant analysis algorithm were performed on the dataset. The results revealed that PAPs from different species could be clearly classified based on the presence or absence of fatty acid compounds with high sensitivity and specificity (>0.95), except for the discrimination of bovine MBM in the mixed dataset. It was possible to distinguish FM samples in the mixed dataset, ruminant MBM from non-ruminant MBM and FM, and porcine MBM from poultry MBM samples based on the concentrations of 34 fatty acid compounds. Further discrimination of PAP samples from different species using fewer selected fatty acids was comparable to or better than discrimination based on the presence or absence and concentration of 34 fatty acid compounds. Practical applications: A new method for discriminating between processed animal proteins (PAP) from different species based on their fat characteristics was established for the first time in this study. Results suggested that the analytical methodology established in this study has great potential for species-specific identification of PAP feed with respect to the global 'mad cow' crisis. PCA visualisation based on the presence or absence of fatty acid, MBM, meat and bone meal, FM, fish meal. [ABSTRACT FROM AUTHOR]

Purpose: To develop in-silico model for predicting percutaneous absorption and disposition kinetics of chemicals in skin layers so as to facilitate the design of transdermal drug delivery systems and skin care products, and risk assessment of occupational or consumer exposure. Methods: A general-purpose computer model for simulating skin permeation, absorption and disposition kinetics in the stratum corneum, viable dermis and dermis has been developed. Equations have been proposed for determining the partition and diffusion properties of chemicals by considering molecular partition, binding and mobility in skin layers. In vitro skin penetration data of 12 chemicals was used to validate the model. Results: The observed and simulated permeation and disposition in skin layers were compared for 12 tested chemicals. For most tested chemicals, the experimental and model results are in good agreement with the coefficient of determination >0.80 and relative root mean squared error <1.20. The disposition kinetic parameters of the maximum concentration and the area under the curve in the viable epidermis and dermis initially increased with hydrophobicity, but reached maxima and then decreased with further increase of hydrophobicity. Conclusions: By considering skin physiological structure and composition, the partition and diffusion properties of chemicals in skin layers are determined. This allows in-silico simulation of percutaneous permeation, absorption and disposition kinetics of wide chemical space. The model produced results in good agreement with experimental data of 12 chemicals, suggesting a much improved framework to support transdermal delivery of drug and cosmetic actives as well as integrated risk assessment. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the permeation of hydrophilic molecules is of relevance to many applications including transdermal drug delivery, skin care as well as risk assessment of occupational, environmental, or consumer exposure. This paper reviews recent advances in modeling skin permeability of hydrophilic solutes, including quantitative structure–permeability relationships (QSPR) and mechanistic models. A dataset of measured human skin permeability of hydrophilic and low hydrophobic solutes has been compiled. Generally statistically derived QSPR models under-estimate skin permeability of hydrophilic solutes. On the other hand, including additional aqueous pathway is necessary for mechanistic models to improve the prediction of skin permeability of hydrophilic solutes, especially for highly hydrophilic solutes. A consensus yet has to be reached as to how the aqueous pathway should be modeled. Nevertheless it is shown that the contribution of aqueous pathway can constitute to more than 95% of the overall skin permeability. Finally, future prospects and needs in improving the prediction of skin permeability of hydrophilic solutes are discussed. [Copyright &y& Elsevier]

Abstract: A comparative study on conventional and microwave-assisted liquefaction of corn stover has been carried out using ethylene glycol (EG) as liquefacient and sulfuric acid as catalyst. Microwave dramatically increased the liquefaction extent and rate compared to conventional heating. The liquefied products and residues in both methods have been investigated using gel permeation chromatography (GPC), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM). The GPC results show that the molecular weight of liquefied products with conventional heating is significantly greater than those of microwave-assisted liquefaction. The FTIR spectra indicate that there are significant differences in the hydroxyl and carbonyl group contents in the liquefied products with the two methods. The residue from microwave-assisted liquefaction mainly consisted of mineral matter. Many granules appeared on the surface of microwave liquefied residue according to SEM observation. [Copyright &y& Elsevier]

Abstract: High-speed counter-current chromatography methods, combined with resin chromatography were applied to the separation and purification of flavonoid glycosides from the Chinese medicinal herb, Radix Astragali. Five flavonoid glycosides, namely calycosin-7-O-β-d-glucoside, ononin, (6aR, 11aR)-9,10-dimethoxypterocarpan-3-O-β-d-glucoside, (3R)-2′-hydroxy-3′,4′-dimethoxyisoflavan-7-O-β-d-glucoside and calycosin-7-O-β-d-glucoside-6′′-O-acetate, were obtained. Among them, calycosin-7-O-β-d-glucoside-6′′-O-acetate was preparatively separated from Radix Astragali for the first time. Their structures were identified by ESI–MS, 1H NMR, 13C NMR, and 2D NMR. [Copyright &y& Elsevier]

Abstract: The use of near infrared reflectance spectroscopy (NIRS) to predict minerals concentration (K, Na, Ca, Mg, Fe) in straw samples was investigated in this study. A total of 222 straw samples were collected in rural area of most provinces in China. Two types of straw samples were prepared, directly cut specimens and oven-dried, milled specimens. The spectra of two kinds of samples were employed to correlate with minerals concentration. Different spectral pre-treatments and regression methods were trialled to optimize the calibration. Coefficient of determination in prediction and standard error of prediction (SEP) were 0.69, 0.54, 0.73, 0.79, 0.41 and 3.77mgg−1, 0.69mgg−1, 0.58mgg−1, 0.31mgg−1, 0.11mgg−1 for directly cut straw; 0.85, 0.70, 0.82, 0.85, 0.63 and 2.35mgg−1, 1.46mgg−1, 0.47mgg−1, 0.27mgg−1, 0.13mgg−1 for dried milled samples, respectively. [Copyright &y& Elsevier]

Abstract: The use of animal protein feeds such as meat meal or meat and bone meal (MMBM) play an important role in the feed manufacturing industry, but their safe and healthy use in animal feeds is of public concern in order to prevent the spread of bovine spongiform encephalopathy (BSE). The objective of the present work was to develop a technique using near infrared reflectance spectroscopy (NIRS) that would be suitable for detecting and quantifying contaminating levels of MMBM in fishmeal. To this end, a partial least squares (PLS) discriminant analysis and a modified partial least squares (MPLS) quantitative analysis, using visible and NIRS, were developed using a calibration set of 186 samples including 90 samples of pure fishmeal and 96 samples adulterated with MMBM at levels ranging from 10 to 320g/kg. An external validation set, comprised of 39 pure samples and 54 adulterated samples, was used to validate the calibration model. A PLS discriminant analysis model developed with mathematic pretreatment 1,4,4,1, successfully detected fishmeal adulterated with MMBM. External validation indicated that all samples were discriminated correctly. A MPLS quantitative model, developed with mathematic pretreatment 1,4,4,1, also successfully predicted the MMBM in fishmeal with standard error of cross-validation (SECV) of 27.89g/kg and ratio of the standard deviation of the validation set to the standard error of prediction (RPD) of 3.37. The calibration and validation results confirm that NIRS could provide the feed industry and inspection bodies with a rapid, non-destructive and non-invasive technique for the detection and quantification of MMBM in fishmeal. [Copyright &y& Elsevier]

Abstract: Exploration of straw resources for energy production has been attracting agricultural scientists and engineers for decades. And the heating value of straw has always been the focus when initiating a straw-based biomass energy project. Nevertheless determination of heating values of straw needs delicate and expensive calorimeter, and is time-consuming. It’s quite desirable to develop quick and easy model predicting heating values of straw. In this study, we proposed three applicable models, first two are multiple linear regression (MLR) equations by contents of moisture, ash, and volatile matter, the other one is based on the near infrared spectroscopy (NIRS) technology. All the models provide satisfactory estimations of heating values of straw samples. The adjusted determination coefficients for MLR models were 0.9049 and 0.9039, and determination coefficients of calibration for NIRS model was 0.9604; When evaluated on independent validation, the determination coefficients were 0.8595, 0.8524 and 0.8946, respectively. The results indicated that both MLR models and NIRS model have the potential to predict the heating values of straw, while the NIRS model presented better accuracy. [Copyright &y& Elsevier]

This study explored the feasibility of determining the content of several nutrient metals (K, Ca, Mg, Fe and Zn) in animal manure compost products in China using near infrared spectroscopy (NIRS). Samples of 120 compost products were collected from 22 provinces in China. The spectra were scanned obtained with a FT–NIRS system. For fresh samples, the validation coefficient of determination (r 2), standard error of prediction (SEP) and the ratio of the standard deviation in the validation set to the standard error of prediction (RPD) were 0.69, 5.08g/kg and 1.83 for K, 0.46, 17.99g/kg and 1.33 for Ca, 0.54, 1.73g/kg and 1.42 for Mg, 0.86, 1.14g/kg and 2.55 for Fe and 0.65, 62.95mg/kg and 1.71 for Zn, respectively. For dried samples, the r 2, SEP and RPD were 0.68, 5.68g/kg and 1.79 for K, 0.78, 15.34g/kg and 2.12 for Ca, 0.72, 2.07g/kg and 1.81 for Mg, 0.84, 1.49g/kg and 2.27 for Fe and 0.57, 86.32mg/kg and 1.52 for Zn, respectively. The results showed that the NIRS technique is a potential method for predicting nutrient metal content of animal manure compost products. However, further research is needed to improve the prediction precision of calibration models by enlarging the number of samples and using other chemometric methods. [Copyright &y& Elsevier]

Abstract: Microwave-assisted extraction (MAE) technique was developed for the fast extraction of flavonoids from Radix Astragali. Several influential parameters of the MAE procedure (microwave power, extraction cycles, ethanol concentration, extraction temperature, irradiation time, and solvent to material ratio) were studied for the optimization of the extraction protocol. The maximum yield of flavonoids with MAE was obtained by dual extraction with 90% ethanol 25ml/g material at 110°C for 25min. No degradation of the flavonoids was observed using the developed extraction protocol. The optimal yield with MAE 1.190±0.042mg/g were close to that of Soxhlet extracted with methanol for 4h (1.292±0.033mg/g) and higher than that of ultrasound assisted extraction with methanol for 2× 30min and heat reflux extraction with 90% ethanol for 2× 2h. [Copyright &y& Elsevier]

Response surface methodology (RSM) was applied to predict optimum conditions for microwave-assisted extraction (MAE) of flavonoid from Radix Astragali. A central composite design was used to monitor the effect of temperature, extraction time, solvent-to-material ratio, and the ethanol concentration on yield of total flavanoid (TFA). Optimum extraction conditions were predicted as 108.2°C, 26.7 min, 23.1 ml/g solvent-to-material ratio and 86.2% ethanol. The maximum yield 1.234±0.031 mg/g was close to the yield of Soxhlet and higher than that of ultrasound assisted extraction and heat reflux extraction. MAE was an effective alternative to conventional extraction methods. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis of lignocellulosic biomass is an attractive method for sustainable cellulosic ethanol production. Considering the complex lignin-cellulose-hemicellulose network of lignocellulosic biomass, enzymatic hydrolysis is a complicated heterogeneous catalytic process and is affected by numerous factors. To reveal the mechanism and obtain the main influencing factors of enzymatic hydrolysis is of great significance to optimize the hydrolysis condition and guide the hydrolysis design. This work comprehensively reviewed the research progress of enzymatic hydrolysis using both experimental and theoretical model evidence. Experimental study of the pretreatment indicated that physicochemical or acid pretreatment is preferable for herbaceous feedstocks, while alkaline pretreatment is proved to be more suitable for lignin-rich woody feedstocks. Preceded by hydrothermal or chemical pretreatment can decrease the energy consumption of mechanical refining. The recalcitrance of different parameters including the enzyme and substrate properties to enzyme adsorption and hydrolysis was comparatively analyzed to optimize the reaction. Theoretical models were comprehensively studied to elucidated the mass transfer mechanism at the molecular level so as to further reveal the reaction mechanism and the key rate-limiting step. Experimental and modeling studies both indicated that the accessible cellulose surface area and pore volume are the main parameters limiting the hydrolysis. Enzyme diffusion is a key rate-limiting step in the beginning of the reaction but affects little for particles with a radii smaller than 5 × 10−3 cm. This paper also deeply analyze the linking between experimental and modeling studies which provide some meaningful reference for the optimization of the conversion process. Image 1 • Different pretreatments result in variations in composition and structure of biomass. • Experimental study on hydrolysis qualitatively optimize the parameters. • The model study quantitatively analyzes the rate-limiting step. • The cellulose surface area and pore volume are major parameters affecting hydrolysis. [ABSTRACT FROM AUTHOR]

Regulative composting variables, like aeration, turning and additive, are critical factors for low-emission and eco-friendly aerobic composting. The main variables (aeration, turning, and additive) on greenhouse gas (GHG) emission rates and spatial GHG concentrations in the pores of composting piles during the large-scale composting were investigated under a typical trough composting system. An engineering model combined momentum transfer was built to simulate the airflow, temperature, and oxygen concentration distribution; thus, the composting equipment parameters could be preliminarily ensured. The aeration period emitted more carbon dioxide per unit time than the non-aeration period. Over 83% of methane was emitted during nonaeration period. GHG emissions in after-turning period were lower than those both in the nonaeration and aeration periods. Through modeling, momentum lost around 34% by frictional resistance when air flows in pipes. The difference of inlet oxygen velocity distribution of pipe's pores was not over 10%, because high pressure provided by a fan could slow down the frictional resistance along the pipeline. The temperature distribution simulation followed the rules of heat diffusion and convection. The oxygen concentration in piles was transferred by its concentration condition fitting Fick law. Model well simulated the actual condition and composting routine could provide support for composting system design and composting management. Because of the complex condition of large-scale composting, modeling of the airflow simulation on GHG emissions should be further investigated. Image 1 • Aeration promotes GHGs overflow from pores and inhibits the anaerobic environment. • Per unit time, more CO 2 and less CH 4 and emitted during the aeration period. • Model simulated airflow and velocity distribution in the pipes and compost piles. • Momentum lost near 34% by resistance when air flows in pipes by modeling. • Distribution of temperature and oxygen concentration were simulated by model. [ABSTRACT FROM AUTHOR]

To promote the green development of agriculture by returning biochar to farmland, it is of great significance to simultaneously detect heavy and nutritional metals in agricultural biochar. This work aimed first to apply laser-induced breakdown spectroscopy (LIBS) for the determination of heavy (Pb, Cr) and nutritional (K, Na, Ca, Mg, Cu, and Zn) metals in agricultural biochar. Each batch of collected biochar was prepared to a standardized sample using the separating and milling method. Two types of univariate analysis model were developed using peak intensity and integration area of the sensitive emission lines, but the performance did not satisfy the requirements of practical application because of the poor correlations between the measured values and predicted values, as well as large relative standard deviation of the prediction (RSDP) values. An ensemble learning algorithm, adaboost backpropagation artificial neural network (BP-Adaboost), was then used to develop the multivariate analysis models, which had a more robust performance than traditional univariate analysis, partial least squares regression (PLSR), and backpropagation artificial neural network (BP-ANN). The optimized RSDP values for K, Ca, Mg, and Cu were less than 10%, while the RSDP values for Pb, Cr, Zn, and Na were in the range of 10–20%. Moreover, the pairwise t-test of its prediction set showed that there was no significant difference between the measurements of LIBS and ICP-MS. The promising results indicate that rapid and simultaneous detection of major heavy and nutritional metals in agricultural biochar can be achieved using LIBS and reasonable chemometric algorithms. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar could reduce 6% CO 2 , 66% CH 4 and 32% NH 3 emissions. • Particle size distributions of compost tend to be smaller. • Wheat straw biochar improves proportion of < 200 μm size distributions. • Wheat straw biochar improves aerobic layer thickness (Lp) and oxygen infiltration. • Along the compost material to biochar, aromatic compounds are gradually increasing. In recent research, biochar has been proven to reduce the greenhouse gases and promote organic matter during the composting. However, gas degradation may be related to the microstructure of compost. To investigate the mechanism of biochar additive, composting was performed using swine manure, wheat straw and biochar and representative solid compost samples were analyzed to characterize the mixed biochar and compost particles. We focused on the microscale, such as the particle size distributions, surface morphologies, aerobic layer thicknesses and the functional groups. The biochar and compost particle agglomerations gradually became weaker and the predominant particle size in the experiment group was < 200 μm. The aerobic layer thickness (Lp) was determined by infrared spectroscopy using the wavenumbers 2856 and 1568 cm−1, which was 0–50 μm increased as composting proceeded in both groups. The biochar increased Lp and facilitated oxygen penetrating the compost particle cores. Besides, in the biochar-swine manure particle interface, the aliphatic compound in the organic components degraded and the content of aromaticity increased with the composting process, which was indicated by the absorption intensity at 2856 cm−1 decreasing trend and the absorption intensity at 1568 cm−1 increasing trend. In summary, biochar performed well in the microscale of compost pile. [ABSTRACT FROM AUTHOR]

[Display omitted] • Membrane coverage technology (CT) was suitable for dairy manure aerobic composting. • CH 4 and N 2 O emission decreased by 99.89% and 60.48% in the CT group. • The total greenhouse gas emission decreased by 70.76% in the CT group. • Intermittent aeration promoted the greenhouse gas emission reduction performance. • Aeration period repaired the water layer to reduce NH 3 emission. In this study, the effects of covering the compost pile with a semi-permeable membrane in combination with intermittent aeration on the gas emissions during aerobic composting from the solid fraction of dairy manure at industrial scale were investigated. A large-scale composting experiment was carried out to compare a membrane-covered (CT) group with a control (CK) group. The results indicated that the CT group could maintain a suitable aerobic and positive micro-pressure environment. The carbon dioxide, methane, nitrous oxide, and ammonia emissions outside the membrane during the aeration interval were reduced by 64.23%, 70.07%, 54.87%, and 11.32%, respectively, compared with that inside the membrane. It was also determined that the methane and nitrous oxide emissions from the CT group were reduced by 99.89% and 60.48% relative to the CK group, confirming that the combined process represented a novel strategy for reducing gas emissions during dairy manure composting. [ABSTRACT FROM AUTHOR]

Background: High-solids enzymatic hydrolysis has attracted increasing attentions for the production of bioethanol from lignocellulosic biomass with its advantages of high product concentration, water saving, and low energy and capital costs. However, the increase of solids content would worsen the rheological properties, resulting in heat/mass transfer limitation and higher mixing energy. To address these issues, ball milling was applied to corn stover prior to enzymatic hydrolysis, and the rheological behaviors and digestibility of ball-milled corn stover under high-solids loading were investigated. Results: Ball milling significantly modified the physicochemical properties of corn stover. The apparent viscosity of slurries at 30% solid loading decreased by a factor of 500 after milling for 60 min, and the yield stress was less than 10 Pa. The dramatic decrease of viscosity and yield stress enabled the hydrolysis process to be conducted in shake flask, and remained good mixing. Meanwhile, the estimated energy consumption for mixing during saccharification decreased by 400-fold compared to the untreated one. The resultant hydrolysate using 10 FPU g−1 solids was determined to contain 130.5 g L−1 fermentable sugar, and no fermentation inhibitors were detected. Conclusions: The proposed ball milling pretreatment improved rheological behavior and sugar yield of high-solids corn stover slurry. Ball milling enables high-solids slurry to maintain low viscosity and yield stress while obtaining a non-toxic high-concentration fermentable syrup, which is undoubtedly of great significance for inter-unit processing, mixing and downstream process. In addition, the energy input for ball milling could be balanced by the reduced mixing energy. Our study indicates ball milling a promising pretreatment process for industrial bioethanol production. [ABSTRACT FROM AUTHOR]

The prehydrolysate from dilute acid pretreatment of lignocellulosic feedstocks often contains inhibitory compounds that can seriously inhibit the subsequent enzymatic and fermentation processes. Acetic acid is one of the most representative toxic compounds. In this research, alkaline deacetylation of corn stover was carried out using sodium carbonate under mild conditions to selectively remove the acetyl groups of the biomass and reduce the toxicity of the prehydrolysate. The deacetylation process was optimized by adjusting factors such as temperature, treatment time, and sodium carbonate concentration. Sodium carbonate solutions (2~6 wt%) at 30~50 °C were used for the deacetylation step, followed by dilute acid pretreatment with 1.5% H2SO4 at 121 °C. Results showed that the acetyl content of the treated corn stover could be reduced up to 87%, while the hemicellulose loss remained low. The optimal deacetylation condition was found to be 40 °C, 6 h, and 4 wt% Na2CO3, resulting in a removal of 80.55% of the acetyl group in corn stover and a hemicellulose loss of 4.09%. The acetic acid concentration in the acid prehydrolysate decreased from 1.38 to 0.34 g/L. The enzymatic hydrolysis of solid corn stover and the whole slurry after pretreatment increased by 17% and 16%, respectively. [ABSTRACT FROM AUTHOR]

Highlights • Pretreatment of corn stover lignocellulose facilitated later cellulase hydrolysis. • Pulverization followed by phosphoric acid treatment was optimal pretreatment. • Pretreatment affected lignocellulose particle size, crystallinity and structure. • Light aided sugar release during cellulase hydrolysis of pretreated lignocellulose. Abstract Lignocellulosic biomass from corn stover holds promise as a raw material for the production of alternative energy to replace fossil fuels. In this study, structural properties of corn stover after pretreatment using mechanical pulverization with or without subsequent phosphoric acid treatment were investigated. The results showed that a pulverization step loosened the compact structure of corn stover lignocellulose and effectively reduced particle size, while both pulverization and phosphoric acid pretreatment steps altered the crystallinity index. During pretreatment, hemicellulose content was reduced and accessibility of β-1,4 glycosidic bonds to hydrolysis by cellulase increased, while almost all lignin was retained. The results showed that the combined two-step pretreatment method improved sugar yield from lignocellulose during subsequent enzymatic hydrolysis from 20.01 mg/g to 41.41 mg/g in glucose yield. These results should guide the development of methods for improved lignocellulose conversion to sugars for enhanced bioethanol production. [ABSTRACT FROM AUTHOR]

• Different manures were carbonated by slow pyrolysis and HTC at different temperatures. • Hydrochar had higher heating value, energy yield, and lower ash content. • HTC narrowed the weight loss temperature range of manures. • Dairy and beef manures showed higher energy yield and better combustion property. Slow pyrolysis and hydrothermal carbonization (HTC) of organic wastes for char preparation has been proved as an effective way for livestock manure management. Livestock manure chars were prepared by slow pyrolysis (400, 500, 600 °C) and hydrothermal carbonization (180, 210, 240 °C) at different reaction temperatures. The influences of manure type and reaction condition to element content, calorific value, char yield, energy yield, and combustion characteristic were investigated. The results illustrate that thermochemical process can strongly affect the properties of pyrolytic char and hydrochar. Compared to pyrolytic char, the hydrochar had higher heating value, higher energy yield, and lower ash content with respect to the same feedstock. The livestock manure type could also influence the properties of biochars/hydrochars. Hydrochars from swine manure, broiler litter, and layer chicken litter achieved the highest energy yield of 65.5%, 56.9%, and 64.4% at 210 °C. Dairy cattle manure and beef cattle manure displayed higher energy yield and higher comprehensive combustibility index than other manures. Furthermore, HTC can narrow the weight loss temperature range in differential thermogravimetric curve of manures. Therefore, HTC is considered as a more effective approach in carbonizing animal manure for solid biofuel compared to slow pyrolysis. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Hydrophobicity and surface charge are the key factors affecting cellulase adsorption. • Specific surface area and crystallinity are the key factors affecting glucose yield. • Ball milling can greatly reduce the enzyme use. • Increasing enzyme binding is not necessary for higher initial hydrolysis rate. Abstract This study evaluated the effects of physicochemical properties of a series of ball-milled cellulose on cellulase adsorption and glucose yield. The relationship between cellulase adsorption and initial hydrolysis rate was also discussed. We found that hydrophobicity and surface charge are the key factors affecting cellulase adsorption on ball-milled cellulose. The results demonstrated that glucose yield had a positive correlation with specific surface area, while showed a negative correlation with particle size, degree of polymerization and crystallinity. Among these properties, specific surface area and crystallinity are the key factors affecting glucose yield. As ball milling progressed, cellulose showed lower enzyme adsorption capacity/amount of bound enzyme during initial stage of hydrolysis, but had higher initial hydrolysis rate. The enhanced rate is attributed to the fact that the amorphous region produced by ball milling reduces the free energy required for decrystallization thus increases the catalytic efficiency of the bound enzyme. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Granular-biochar improved pore volume and was benefit to methanotrophs activities. • Higher aromatic compounds on surface of bamboo biochar and NO 3 − formed π–π EDA. • Rice straw biochar is rich in reactive functional groups to adsorb NH 4 +. • Powder bamboo biochar was most suitable for controlling GHG and ammonia emissions. Abstract Greenhouse gas and ammonia emissions during composting with different biochar types and particle sizes were investigated. Compared with powder-biochar, granular-biochar improved pore connectivity and was benefit to methanotrophs activities, like Methylococcaceae , reducing CH 4 emissions. At the same particle size, bamboo biochar (BB) had a higher pore volume and more aerobic microenvironment within the compost than rice straw biochar (RSB), reducing GHG emissions. Bamboo biochar had high aromatic compound and NO 3 − concentrations and therefore surface π–π electron donor/acceptor interactions, causing low N 2 O emissions and inhibiting denitrifying bacteria (e.g., Bacteroidales). More C O and C O bonds in rice straw biochar than bamboo biochar caused lower NH 3 emissions using rice straw than bamboo biochar. Powdered biochar had more exposed reactive functional groups and decreased NH 3 production better than granular biochar. Powdered bamboo biochar controls gaseous emissions better than other biochars during aerobic pig manure/wheat straw composting. [ABSTRACT FROM AUTHOR]

Abstract The Tibetan Plateau is a traditional pastoral area in the western part of China where animal husbandry is a local pillar. The cattle manure in this area accounts for 77% of the total amount of local livestock and poultry manure. To reduce the harmful side effects associated with cattle manure use in the Tibetan Plateau region of China, a highly-efficient semi-permeable membrane-covered compost system was used. Main physicochemical and gas indicators were measured to investigate the effects of this compost system. Overall, the composting temperature was above 50 °C for 34 days, which resulted in the moisture content and germination index of the final compost being 30 ± 1% and 84%, respectively. Additionally, the obstruction of semi-membrane, high oxygen and water concentrations under the semi-permeable membrane reduced the emission of greenhouse gases and ammonia, with cumulative emissions of CO 2 , CH 4 , N 2 O and NH 3 outside the membrane being 73%, 96%, 80% and 65% lower than those inside the membrane, respectively. Moreover, the maximum cumulative concentrations of CO 2 , CH 4 , N 2 O and NH 3 outside the membrane were 98%, 95%, 72% and 58% lower than those inside the membrane, respectively. This research demonstrated the advantages of using the semi-permeable membrane-covered composting system to reduce GHGs as well as ammonia production and emissions and the responsible mechanisms. The semi-permeable membrane-covered composting system could be a good choice for treatment of manure in the Tibetan Plateau region. Highlights • The analysis results of physicochemical indicators showed a positive aerobic composting process. • The GHGs and NH 3 emissions outside were much lower than those inside the semi-membrane. • The mechanism of gas reduction depended on the interaction between the semi-membrane and the different gases. [ABSTRACT FROM AUTHOR]

The catalytic hydrolysis/alcoholysis of biomass carbohydrates into levulinic acid/levulinate esters (alkyl levulinates) as green biofuels and value-added chemicals holds great promise for achieving the goals of sustainable chemistry. Bifunctional catalysts with Brønsted- and Lewis-acidic sites have been widely reported to boost the efficiency of both processes. However, current understanding of the origin of the enhancement in alcoholic media is still in its infancy compared to that in aqueous media. Herein, we investigate the reaction process of glucose in methanol using a representative bifunctional catalyst (aluminum phosphotungstate) and its Brønsted-acid form (phosphotungstic acid), respectively. Isotopic labeling experiments were first applied to monitor the potential intermediates in glucose methanolysis. Coupling with mass spectrometric analysis and theoretical calculations, it has been revealed that Al3+ ions may accelerate the rate-limiting step by inducing ring opening of the key intermediate, methyl- D -glucopyranoside (MDGP), to D -glucose dimethyl acetal, rather than the prevalent speculation of facilitating the isomerization of MDGP to methyl fructoside. These findings refresh and reinforce our knowledge of the mechanism behind catalytically producing alkyl levulinates from biomass carbohydrates and provide a basis for the rational design of superior catalysts for biomass valorization. [ABSTRACT FROM AUTHOR]

This study investigated effects of various pretreatments on characteristics of compression molded wheat straw and molding energy consumption. And correlative mechanism was explored. Pretreatments included natural air drying, vacuum sealing, 4% ammonium hydroxide + vacuum sealing. Hemicellulose and lignin contents and crystallinity decreased following pretreatments, while surface porosities increased. Cellulose and ash levels and lower heat value were not significantly affected ( P >  .05), while water resistance decreased and relax density and fall strength satisfied relevant standards. Ignition index and comprehensive combustibility index of samples treated with 4% ammonium hydroxide + vacuum sealing were the greatest, and molding energy consumption was also the lowest. Optimal pretreatment time was 21 days. Mechanism analysis indicated that crystallinity affected water resistance, lignin affected combustion characteristics and hemicellulose affected molding energy consumption to the greatest extent. Overall, 4% ammonium hydroxide + vacuum sealing pretreatment had the most beneficial effect on compression molding and resulted in the lowest energy consumption. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the ability of Fourier transform infrared (FT-IR) spectroscopy to authenticate adulterated animal-derived feedstuff. A total of 18 raw meat and bone meals (MBMs), including 9 non-ruminant MBMs and 9 ruminant MBMs, were mixed to obtain 81 binary mixtures with specific proportions (1–35%). Lipid spectral characteristics were analyzed by FT-IR spectroscopy combined with chemometrics. Changes in FT-IR spectra were observed as adulterant concentration was varied. The results illustrate ruminant adulteration can be successfully distinguished based on lipid characteristics. PLS model was established to quantify ruminant adulteration, which was shown to be valid (R 2 P > 0.90). Furthermore, the ratios of C C/C O and C C/C H(CH 2 ), as well as the number of C H( CH 2 ) in the fatty acids of adulterated lipids, were calculated, which showed that differences in the trans fatty acid content and the degree of unsaturation were the main contributors to determination of adulteration based on FT-IR spectroscopy. [ABSTRACT FROM AUTHOR]

This study investigated the effects of biochar powder on oxygen supply efficiency and global warming potential (GWP) in the large-scale aerobic composting pattern which includes cyclical forced-turning with aeration at the bottom of composting tanks in China. A 55-day large-scale aerobic composting experiment was conducted in two different groups without and with 10% biochar powder addition (by weight). The results show that biochar powder improves the holding ability of oxygen, and the duration time (O 2 >5%) is around 80%. The composting process with above pattern significantly reduce CH 4 and N 2 O emissions compared to the static or turning-only styles. Considering the average GWP of the BC group was 19.82% lower than that of the CK group, it suggests that rational addition of biochar powder has the potential to reduce the energy consumption of turning, improve effectiveness of the oxygen supply, and reduce comprehensive greenhouse effects. [ABSTRACT FROM AUTHOR]

The objective of the present study was to study the changes in compost particle and its relationship with other physicochemical process during aerobic composting employing 5%, 10%, 20% or 0% biochar. Changes of physicochemical and biological parameters and gases emissions indicated that appropriate biochar addition improved both degradation rate and final degree of the organic matter and simultaneously reduced CO 2 , CH 4 , N 2 O and NH 3 emissions. Beneficial properties like stability and high porosity of biochar could optimize composting environment, accelerate the process of composting and facilitate microbial growth during the thermophilic composting stage, with increases of 1.3 × 10 10 to 1.5 × 10 11 cfu/g. Analysis of microstructure characterization of the changes in compost particle indicated that biochar amended contributed to better degradation of compost particle with smaller sizes and a higher degree of looseness. Ultimately, 10% biochar addition optimized organic matter degradation, while reducing ammonia and greenhouse gas emissions and costs. [ABSTRACT FROM AUTHOR]

Spectral denoising offers a basis for effective and accurate quantitative modeling of laser-induced breakdown spectroscopy (LIBS). To provide a solution for the defects of the traditional hard threshold function (HTF) and the soft threshold function (STF) for wavelet denoising methods, an improved wavelet dual threshold function (IWDTF) has been developed. Simulation analyses proved that the IWDTF could provide a better denoising performance than the traditional functions. The IWDTF was applied to LIBS denoising and quantitative modeling of the Cu and Zn contents in representative Chinese aerobic composting samples. The results showed that the best spectral denoising effects for the Cu and Zn models were achieved when the adjustment parameters k 0 , a, and θ were 0.9, 0.7 × λ 1 , and 0.1 × π, and 0.2, 0.2 × λ 1 , and 0.1 × π, respectively, and corresponding models' performances for Cu and Zn were both greatly improved, yielding R p 2 of 0.9807 and 0.9177, RMSEP of 67.49 mg/kg and 84.92 mg/kg, and RPD of 3.12 and 3.07, respectively. [ABSTRACT FROM AUTHOR]

Background: The dense structure of cellulose lowers its reactivity and hinders its applications. Concentrated sulfuric acid is an ideal solvent to dissolve cellulose and thus has been used widely to treat cellulose. However, the changes of cellulose after reaction with concentrated sulfuric acid at near-limit S/L ratio and its effect on enzymatic saccharification still need further investigation. Results: In this study, the interactions between cellulose (Avicel) and 72% sulfuric acid at very low acid loading conditions of 1:2 to 1:3 (S/L ratio) were studied for the enhanced production of glucose. The Avicel gradually transformed from cellulose I structure to cellulose II structure during the sulfuric acid treatment. Other physicochemical characteristics of Avicel also changed dramatically, such as the degree of polymerization, particle size, crystallinity index, and surface morphology. After acid treatment, both the yield and productivity of glucose from cellulose increased significantly under a very low enzyme loading of 5 FPU/g-cellulose. The glucose yields for raw cellulose and acid-treated (30 min) were 57% and 85%, respectively. Conclusion: Low loadings of concentrated sulfuric acid were proven to be effective to break the recalcitrance of cellulose for enzymatic saccharification. A positive correlation between cellulose CrI and glucose yield was found for concentrated sulfuric acid-treated cellulose, which was opposite to previous reports. Cellulose II content was found to be an important factor that affects the conversion of cellulose to glucose. [ABSTRACT FROM AUTHOR]

Biorefractory high polymer lignocellulosic compositions may limit rapid composting and stable decomposition. Because their degradation during composting is not well understood, the correlation with microbial community profiles was assessed to reveal degradation mechanism of lignocellulosic compositions. Testing of chicken manure aerobic composting with added biochar was performed using phospholipid fatty acid (PLFA) and correlation analysis. Results demonstrated a good composting effect with good dynamic correlation between microbial characteristic (PLFA) and lignocellulosic compositions' degradation ratio. The prediction model for hemicellulose degradation ratio (R 2 = 0.97, SEP = 3.24) and the prediction model for cellulose degradation ratio (R 3 = 0.94, SEP = 3.09), built using PLFA 16:0–18:2ω6c and PLFA 18:2ω6c–18:3ω3 as the arguments had good predictive ability. Based on microbial analysis and quantitative characterization of the degradation ratio, the prediction models provided methodological support for delineating the mechanism of lignocellulosic compositions' degradation during chicken manure aerobic composting with added biochar. [ABSTRACT FROM AUTHOR]

This study characterized some physicochemical and biological parameters to systematically evaluate the dynamics of oxygen supply and consumption during large-scale trough composting in China. The results showed that long active phases, low maximum temperatures, low organic matter losses and high pore methane concentrations were observed in different composting layers. Pore oxygen concentrations in the top, middle and bottom layers maintained <5 vol.% for 40, 42 and 45 days, respectively, which accounted for more than 89% of the whole period. After each mechanical turning, oxygen was consumed at a stable respiration rate to a concentration of 5 vol.% in no more than 99 min and remained anaerobic in the subsequent static condition. The daily percentage of time under aerobic condition was no more than 14% of a single day. Therefore, improving FAS, adjusting aeration interval or combining turning with forced aeration was suggested to provide sufficient oxygen during composting. [ABSTRACT FROM AUTHOR]

High-solids saccharification and fermentation is central to the cost-competitive production of cellulosic ethanol, but it often comes with unsatisfactory conversion efficiency because of mixing and heat/mass transfer limitations. The use of ball milling can considerably enhance enzymatic hydrolysis with desirable rheological properties at high solids, and we obtained a high sugar concentration of 162 g/L with a glucose yield of 74% after enzymatic hydrolysis. However, little is known about the impact of ball milling on subsequent fermentation of sugars to ethanol as well as the feasibility of producing high titer bioethanol from ball-milled materials at high solids loading. Here, we systematically evaluated various fermentation strategies to maximize the efficiency and economic benefits of bioethanol production using ball-milled corn stover at high solids loading. A high ethanol titer and productivity can be achieved up to 71.8 g/L and 2 g/L/h, respectively, with an ethanol yield of 58.8%. These results suggest the tremendous potential of ball milling for bioethanol production. [Display omitted] [ABSTRACT FROM AUTHOR]

Catalytic fast hydrothermal liquefaction (HTL) of cow manure was performed to investigate the effect of reaction temperature (400–450 °C), resident time (10–24 min), and catalyst type (NaOH, Na 2 CO 3 , NaHCO 3 , ZnCl 2 , citric acid, and H 3 PO 4) on products yields and characteristics. The biocrude oils produced from both non-catalytic and catalytic fast HTL processes were characterized by gravimetric analysis, GC/MS, FTIR, CHNS/O elemental analysis, etc. For instance, by introducing Na 2 CO 3 in the fast HTL process under the same condition, the yield and HHV of the biocrude oil were further enhanced to 21.86 wt% and 31.32 MJ/kg, respectively. The physicochemical properties of hydrochars were estimated by SEM, EDX, FTIR, TGA, and CHNS/O elemental analysis. Importantly, the versatile hydrochar generated from catalytic fast HTL process possessed the porous structure, high HHV (e.g., 18.43 MJ/kg) and great thermal stability, indicating huge potentials as an adsorbent, solid fuel, and even catalyst support. To get more insights into the HTL reaction mechanisms, the aqueous phase as an important byproduct was characterized by GC/MS, TOC, and TN analysis; and gas fraction was identified by GC. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The reaction condition for hydrochar production was optimized with 10% PVC dosage. • PVC addition promoted removals of chlorine and inorganic metals within hydrochar. • The combustion performance of hydrochar was improved by increasing PVC dosage. • The reaction mechanism of PVC-promoted hydrothermal carbonization was proposed. Hydrothermal carbonization (HTC) can serve as a promising route to effectively co-valorize biomass and plastic wastes for solid fuel production. However, manure-derived hydrochar for fuel application remains a significant challenge due to its high ash content and low energy density. Polyvinyl chloride (PVC), as a chlorine-containing plastic, subjected to HTC commonly results in the generation of massive acidic wastewater. Herein, we proposed a PVC-promoted HTC route for high energy–density hydrochar production. By utilizing PVC as an in situ acidic additive, the HTC condition was optimized at 275 °C, 30 min, with a PVC addition of 10 %. The hydrochar obtained under the optimized condition exhibited a higher heating value (HHV) of 25.89 MJ/kg, comparable to bituminous coals, and achieve a high energy recovery rate of nearly 70 %. Moreover, the excellent removal efficiencies of inorganic metals and chlorine both exceeding 95 % (except for Fe at 86 %) were observed, owing to the strong interactions between dechlorination and inorganic metals removal. Importantly, it was evidenced that acidic reaction environment was demonstrated to enhance the carbonization degree and modify the hydrochar formation mechanism. Furthermore, the high comprehensive combustion index S of 3.22 × 10−7 %2/(°C3·min2) and low average Ea of 134.20 kJ/mol were achieved, indicating the favorable combustion behaviors. Overall, this work systematically and comprehensively investigated the PVC-promoted HTC of manure waste for advanced solid fuel production and examined its combustion characteristics, unveiling the hydrochar formation mechanism. [ABSTRACT FROM AUTHOR]

• Microscopic FT-IR imaging technology was used to MBM species discrimination. • Accuracy of PLS-DA model using the fragment-related fused pixels reached 0.980. • Analytical efficiency was guaranteed with the consuming time around 4.5 min. This study proposes a novel microscopic FT-IR imaging-based analytical strategy for the discrimination of meat and bone meal (MBM) species. The feasibility of correlation coefficient and PLS-DA methods for the screening of bone and meat fragment-related spectral pixels in MBM microscopic FT-IR imaging was validated. Subsequently, PLS-DA models were established for MBM species-specific analysis based on the screened bone and meat fragment-related spectral pixels. Comparative analysis with the PLS-DA model using all FT-IR pixels demonstrated a significant improvement in the performance of the PLS-DA model based on the fused matrix fragment-related spectral pixels, achieving an accuracy of approximately 0.980. Furthermore, the proposed analytical strategy exhibited a time efficiency advantage with a consumption period of approximately 4.5 min, thereby ensuring high spectral technical efficiency. The findings of this study offer a theoretical basis for the spectral discrimination analysis of agricultural materials with complex matrix compositions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amoxicillin (AMX) and Cu decreased humification by 15.73%. • Humification was affected less by AMX and Cu together than either separately. • AMX and Cu decreased the cellulose degradation rate by 9.01%. • Bacteria played more active roles than fungi in the humification process. • AMX and Cu decreased the number of bacteria involved in humic acid formation. Livestock manure often contains various pollutants. The aim of this study was to investigate how adding amoxicillin (AMX), Cu, and both AMX and Cu (ACu) affected humification during composting and the microbial mechanisms involved. The cellulose degradation rates were 16.96%, 10.86%, and 9.01% lower, the humic acid contents were 18.71%, 12.89%, and 16.78% lower, and the humification degrees were 24.72%, 24.16%, and 15.73% lower for the AMX, Cu, and ACu treatments, respectively, than the control. Adding AMX and Cu separately or together inhibited humic acid formation and decreased the degree of humification, but the degree of humification was decreased less by ACu than by AMX or Cu separately. The ACu treatment decreased the number of core bacteria involved in humic acid formation and decreased carbohydrate and amino acid metabolism during the maturing period, and thereby delayed humic acid formation and humification. The results support composting manure containing AMX and Cu. [ABSTRACT FROM AUTHOR]

The perpetual market demand for polystyrene results in the gradual accumulation of polystyrene waste, placing a serious burden on the environment. This study proposed a promising method to upcycle polystyrene for styrene-derived monomers through catalytic fast pyrolysis. The metals-incorporated biochar catalysts were synthesized from heavy metals-contaminated manure waste for catalytic fast pyrolysis of polystyrene. The experimental results showed that the bimetallic biochar-derived catalyst containing Zn and Cr (Zn-Cr/C) was more conducive to the liquid production, with an extremely high yield of 88.22 wt%. Monometallic Pb-incorporated biochar catalyst (Pb/C) and bimetallic Zn-Cu co-doped on biochar (Zn-Cu/C) were more favorable for the production of pure styrene, with the mass yield of 61.26 wt% and 60.39 wt%, respectively. Additionally, the study elucidated a deep understanding of the reaction mechanisms involved in the catalytic fast pyrolysis of polystyrene. Simply put, this study introduced a new concept to convert heavy metal-contaminated animal manure into metal-incorporated biochar catalysts for catalytic conversion of polystyrene waste in pure styrene-based monomers. [Display omitted] • A new concept of upcycling polystyrene into pure monomers. • Mono-/bi-/tri-metallic Zn, Cu, Pb, Cr-containing biochar catalysts were prepared. • Bimetallic Zn-Cr/C favored the liquid production, with the high yield of 88.22 wt%. • Pb/C was more favorable for pure styrene production, reaching 61.26 wt%. • Trimetallic Zn-Cu-Pb/C had an obviously negative impact on the liquid production. [ABSTRACT FROM AUTHOR]

Cellulose triacetate (CTA) was successfully synthesized from corn stover cellulose (CSC) in the presence of [PyPS]3PW12O40 (IL-POM). The effects of IL-POM contents, reaction temperature, and reaction time on the yield and degree of substitution of CTA were investigated. The synthesized CTA was characterized by SEM, FTIR, and TGA, and the degree of polymerization and solubility in various organic solvents were evaluated. Results showed that the optimum reaction conditions were as follows: 0.04 g of IL-POM, reaction temperature of 140 °C, and reaction time of 45 min, for 0.4 g of CSC and 9 mL of glacial acetic acid. The yield of CTA under optimum reaction conditions was as high as 79.27%, and the degree of substitution was 2.95. SEM and FTIR results showed that the cellulose acetylation occurred, and CTA was synthesized. The TGA results revealed that the decomposition temperature of CTA increased by about 30 °C when compared with that of CSC. A simple, environment-friendly, and efficient process for the preparation of CTA from CSC was constructed, which provides a new pathway for the high-value utilization of corn stover. [ABSTRACT FROM AUTHOR]

On-line analysis of proximates (moisture, ash, volatile matter, and fixed carbon) and lignocellulose components (cellulose, semi-cellulose, and lignin) of coarse-crushed corn stover was investigated using near-infrared spectroscopy (NIRS). Compared with traditional technique, on-line measurement is complex and challenging but provides real-time analysis. The spectrometer operated over a conveyor belt that moved at 20 cm/s, and the distance between the spectrometer scanning window and the surface of the sample was 100 mm. Corn stover samples ( n = 217) were collected from three provinces in China and used to develop the models. Samples were crushed to <50 mm before analysis. After optimized pretreatment, all the NIRS models were developed using partial least squares (PLS) method. The relative standard deviations (RSD) of the models for moisture, ash, volatile matter, fixed carbon, cellulose, semi-cellulose, and lignin were 9.04%, 9.99%, 1.31%, 6.00%, 3.87%, 6.80%, and 5.06%, respectively. On-line analysis of proximates and lignocellulose components of corn stover was possible using this NIRS system. [ABSTRACT FROM AUTHOR]

Background: Valorization of lignocellulosic biomass to obtain clean fuels and high-value chemicals is attractive and essential for sustainable energy and chemical production, but the complex structure of biomass is recalcitrant to catalytic processing. This recalcitrance can be overcome by pretreating biomass into deconstructable components, which involves altering the structural complexities and physicochemical properties. However, the impact of these alterations on biomass deconstruction varies considerably, depending on the pretreatment and subsequent conversion type. Here, we systematically describe the changes in structure and properties of corn stover after ball milling as well as their influence on the following enzymatic saccharification and acid-catalyzed alcoholysis, with the aim of elucidating the relationships between structures, properties and deconstructable potential of lignocellulosic biomass. Results: Ball milling causes dramatic structural changes, since the resistant plant cell walls are destroyed with size reduction to a cellular scale, leading to the increase in surface area and reducing ends, and decrease in crystallinity and thermal stability. As a result, ball-milled corn stover is more susceptible to enzymatic saccharification to fermentable sugars and provides more industrially viable processing approaches, as it is effective at high solids loading and minor enzyme loading, without any other pretreatment. Acid-catalyzed alcoholysis of corn stover to biofuels, on the other hand, is also enhanced by ball milling, but additional processing parameters should be tailored to the needs of efficient conversion. Further, a detailed examination of process variables coupled with a kinetic study indicates that acid-catalyzed alcoholysis is limited by the process variables rather than by the substrate parameters, whereas ball milling facilitates this reaction to some extent, especially under mild conditions, by lowering the activation energy of corn stover decomposition. Conclusions: The efficient catalytic conversion of biomass is closely related to its structure and properties, an understanding of which offers prospects for the rational improvement of methods aimed at more economic commercial biorefineries. [ABSTRACT FROM AUTHOR]