In recent years,the problem of veterinary drug residues in animal-derived foods has attracted worldwide attention.Developing rapid,simple,highly sensitive,and high-throughput veterinary drug residue detection technolo...In recent years,the problem of veterinary drug residues in animal-derived foods has attracted worldwide attention.Developing rapid,simple,highly sensitive,and high-throughput veterinary drug residue detection technologies has become an urgent need.This paper provides a comprehensive review of the pretreatment and analytical techniques for veterinary drug residue analysis,comparing the detection principles,operational procedures,and respective advantages and disadvantages of various detection technologies.It further explores the future development directions of veterinary drug residue detection technologies.展开更多
The addition of high-content crumb rubber(HCCR)in asphalt can effectively address waste tire pollution and provide sustainable environmental and economic advantages.However,the practical application of conventional ru...The addition of high-content crumb rubber(HCCR)in asphalt can effectively address waste tire pollution and provide sustainable environmental and economic advantages.However,the practical application of conventional rubberized binders is significantly limited by high viscosity and poor storage stability.To address these issues,researchers have pretreated crumb rubber(CR)with oil,but high-temperature performance remains insufficient.Therefore,this study aimed to optimize the viscosity,storage stability,and rheological properties of high-content crumb rubber-modified asphalt(HCCRMA)by varying the pretreatment levels of CR and incorporating various additives,including styrene-butadiene-styrene(SBS),deoiled asphalt(DA),or recycled low-density polyethylene(RLDPE).In addition,CR was pretreated with waste cooking oil(WCO)at various ratios,pre-swelling temperatures,and times.The results show that DA exhibits excellent storage stability and lower viscosity compared with other modifiers in HCCRMA,and the 4%RLDPE with pretreated HCCR has the greatest high-temperature rutting resistance.The inclusion of RLDPE increases the stiffness and elasticity of the modified asphalt,which results in greater high-temperature performance.Additionally,the fluorescence microscopy(FM)test confirms that SBS exhibits better dispersion than other modifiers and forms a more homogeneous phase separation in the HCCRMA.All in all,this research achieved an optimal balance of storage stability and rheological properties in asphalt modified with pretreated HCCR and 6%SBS,which provides a valuable reference for performance improvement of HCCR-modified binders.展开更多
Metabolomics as a research field and a set of techniques is to study the entire small molecules in biological samples.Metabolomics is emerging as a powerful tool generally for pre-cision medicine.Particularly,integrat...Metabolomics as a research field and a set of techniques is to study the entire small molecules in biological samples.Metabolomics is emerging as a powerful tool generally for pre-cision medicine.Particularly,integration of microbiome and metabolome has revealed the mechanism and functionality of microbiome in human health and disease.However,metabo-lomics data are very complicated.Preprocessing/pretreating and normalizing procedures on metabolomics data are usually required before statistical analysis.In this review article,we comprehensively review various methods that are used to preprocess and pretreat metabolo-mics data,including MS-based data and NMR-based data preprocessing,dealing with zero and/or missing values and detecting outliers,data normalization,data centering and scaling,data transformation.We discuss the advantages and limitations of each method.The choice for a suitable preprocessing method is determined by the biological hypothesis,the characteristics of the data set,and the selected statistical data analysis method.We then provide the perspective of their applications in the microbiome and metabolome research.展开更多
Lithium-ion batteries(LIBs)are the most popular energy storage devices due to their high energy density,high operating voltage,and long cycle life.However,green and effective recycling methods are needed because LIBs ...Lithium-ion batteries(LIBs)are the most popular energy storage devices due to their high energy density,high operating voltage,and long cycle life.However,green and effective recycling methods are needed because LIBs contain heavy metals such as Co,Ni,and Mn and organic compounds inside,which seriously threaten human health and the environment.In this work,we review the current status of spent LIB recycling,discuss the traditional pyrometallurgical and hydrometallurgical recovery processes,and summarize the existing short-process recovery technologies such as salt-assisted roasting,flotation processes,and direct recycling.Finally,we analyze the problems and potential research prospects of the current recycling process,and point out that the multidisciplinary integration of recycling will become the mainstream technology for the development of spent LIBs.展开更多
Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surfac...Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surface pretreatment experiments with citric acid,tartaric acid,and tannic acid(TA)on magnesite and dolomite as well as flotation experiments on pretreated samples were performed in this study.Experimental results demonstrated that when citric acid and tartaric acid are used for surface pretreatment,the separation effect of magnesite and dolomite is poor.However,when TA is used,the separation effect of magnesite and dolomite improves.SEM and BET analysis indicated that surface pretreatment with TA changes the surface morphology of the two minerals,resulting in additional concave pores on the dolomite surface,and a significant increase in pore size and specific surface area.The adsorption quantity test and contact angle measurement demonstrated that after surface pretreatment with TA,the magnesite adsorption capacity on sodium oleate(NaOL)slightly decreases and the dolomite adsorption capacity on NaOL considerably decreases.XPS detection concluded that the surface pretreatment of TA on the magnesite surface mainly relies on physical adsorption with weak adsorption ability and poor ability to act on Mg sites.The TA surface pretreatment action on the dolomite surface is mainly through chemical adsorption,and it is strongly and selectively adsorbed on the Ca site of dolomite through O.Actual ore rough selection experiments reveal that TA pretreatment successfully removes dolomite from magnesite,resulting in a high-quality magnesite concentrate characterized by a MgO grade of 45.49%and a CaO grade of 0.75%.展开更多
The aim of this work was to evaluate the use of stover from brown midrib(bmr)grain sorghum to produce polyhydroxyalkanoates(PHAs).These mutants produce lignin with novel compositions and/or reduced lignin content that...The aim of this work was to evaluate the use of stover from brown midrib(bmr)grain sorghum to produce polyhydroxyalkanoates(PHAs).These mutants produce lignin with novel compositions and/or reduced lignin content that was hypothesized to result in higher PHA production than when using a wild-type sorghum stover.Five sorghum stover samples[wild-type(control)and four bmr mutants[bmr2,bmr6,and bmr12,and a double bmr mutant:bmr6 and bmr12(stacked)]were evaluated as substrates for poly(3-hydroxybutyrate)(P(3HB))production.When the main sugars in non-detoxified alkali-pretreated sorghum stover hydrolysates(SSHs)were metabolized by Paraburkholderia sacchari for P(3HB)production,the SSHs from bmr plants were demonstrated to be promising feedstocks with a maximum P(3HB)concentration of 7.2 g/L from the bmr6 SSH,while a maximum P(3HB)concentration of 4.2 g/L P(3HB)was produced using wild-type SSH.Moreover,the highest maximum Y_([P(3HB)/sugars])were achieved using stacked SSH and bmr12 SSH(0.44 g/g and 0.42 g/g,respectively).Furthermore,Cuprivadus necator was utilized to evaluate P(3HB)synthesis from the alkaline pretreated liquor(APL)remaining after sorghum stover pretreatment and an oxidative enzyme-mediator-surfactant system(OEMS)was used to improve P(3HB)production from the APLs.A 28-fold increase in PHB production from the bmr2-APL with OEMS compared to the fermentation of the same APL with no OEMS was observed.This is the first published report to use grain sorghum stover to produce polyhydroxyalkanoates(PHAs).Also,a novel combination of PHA production from both sugars and lignin is reported.展开更多
Sewage sludge in cities of Yangzi River Belt,China,generally exhibits a lower organic content and higher silt contentdue to leakage of drainage system,which caused low bioenergy recovery and carbon emission benefits i...Sewage sludge in cities of Yangzi River Belt,China,generally exhibits a lower organic content and higher silt contentdue to leakage of drainage system,which caused low bioenergy recovery and carbon emission benefits in conventional anaerobic digestion(CAD).Therefore,this paper is on a pilot scale,a bio-thermophilic pretreatment anaerobic digestion(BTPAD)for low organic sludge(volatile solids(VS)of 4%)was operated with a long-term continuous flow of 200 days.The VS degradation rate and CH_(4) yield of BTPAD increased by 19.93%and 53.33%,respectively,compared to those of CAD.The analysis of organic compositions in sludge revealed that BTPAD mainly improved the hydrolysis of proteins in sludge.Further analysis of microbial community proportions by high-throughput sequencing revealed that the short-term bio-thermophilic pretreatment was enriched in Clostridiales,Coprothermobacter and Gelria,was capable of hydrolyzing acidified proteins,and provided more volatile fatty acid(VFA)for the subsequent reaction.Biome combined with fluorescence quantitative polymerase chain reaction(PCR)analysis showed that the number of bacteria with high methanogenic capacity in BTPAD was much higher than that in CAD during the medium temperature digestion stage,indicating that short-term bio-thermophilic pretreatment could provide better methanogenic conditions for BTPAD.Furthermore,the greenhouse gas emission footprint analysis showed that short-term bio-thermophilic pretreatment could reduce the carbon emission of sludge anaerobic digestion system by 19.18%.展开更多
Oat husks,a byproduct of oat milling operations with limited economic value,present a promising feedstock for biorefinery processes due to their chemical composition.This study investigates the conversion of C5 carboh...Oat husks,a byproduct of oat milling operations with limited economic value,present a promising feedstock for biorefinery processes due to their chemical composition.This study investigates the conversion of C5 carbohydrates in oat husks into furfural through hydrothermal pretreatment using various phosphate-based catalysts,including H_(3)PO_(4),NH_(4)H_(2)PO_(4),NaH_(2)PO_(4),KH_(2)PO_(4),K_(2)HPO_(4) and K_(3)PO_(4) as catalyst.The catalysts’effectiveness in promoting furfural production was evaluated under identical hydrothermal conditions(treatment time for 60 min at a constant temperature of 170℃ and a catalyst amount).Continuous water steam was used to strip furfural from the reaction zone and minimize its degradation.Results indicated that H_(3)PO_(4) was the most effective catalyst,achieving a furfural yield of 13.99 wt.%,which corresponds to approximately 57%of the theoretical yield.NH4H2PO4 also showed moderate effectiveness,while sodium and potassium phosphate salts were significantly less effective.A scanning electron microscope analysis shows that catalysts with lower pH may disrupt the oat husks external layer thus providing a higher C5 carbohydrates conversion rate into furfural.The chemical complexity of oat husk contributes to side reactions between its carbohydrates and lignin during the hydrothermal treatment.This results in an increase in acid-insoluble lignin and inorganic matter in the oat husk lignocellulosic residue,which can reduce the effectiveness of further cellulose saccharification by enzymatic hydrolysis.展开更多
The increasing demand for sustainable energy solutions necessitates innovative approaches to biomass utilization.This study introduces a comprehensive biorefinery model that valorizes poplar biomass into high-value pr...The increasing demand for sustainable energy solutions necessitates innovative approaches to biomass utilization.This study introduces a comprehensive biorefinery model that valorizes poplar biomass into high-value products,including ethanol,furfural,phenol,and biochar.These products not only serve as promising sources for biofuel and renewable chemicals but also contribute to pollution mitigation.The approach employs a biphasic pretreatment system utilizing p-toluenesulfonic acid,pentanol,and AlCl_(3) under optimized conditions(120℃ for 45 min),achieving remarkable efficiencies of 95.8%xylan removal,90.2%delignification,and 90.7%glucan recovery.The underlying mechanism,elucidated through density functional theory,demonstrates how the disruption of lignin-carbohydrate complexes via electrostatic and hydrogen-bonding interactions enhances product yields.The cellulose-rich substrate yielded 71.3 g/L ethanol,while solubilized xylan converted to 86.7%furfural without additional acid.Furthermore,lignin pyrolysis produced bio-oil containing over 45.2%phenolic compounds,while biochar demonstrated significant adsorptive capacity for perfluorooctanoic acid.Scaling this biorefinery model to process 140 million tons of poplar biomass annually reduces CO_(2)emissions by 75.3 million tons and provides socioeconomic savings of $17.3 billion,supporting sustainable industrial transformation.展开更多
Rapeseed is the primary domestic source of edible vegetable oil in China.Its oil is naturally rich in phytosterols,polyphenols,tocopherols,carotenoids and other lipid-soluble companions,which are highly beneficial to ...Rapeseed is the primary domestic source of edible vegetable oil in China.Its oil is naturally rich in phytosterols,polyphenols,tocopherols,carotenoids and other lipid-soluble companions,which are highly beneficial to human health.Since the content and bioaccessibility of these health-promoting companions are mostly locked during the first post-harvest operation,the pretreatment technology has become the decisive lever for simultaneously maximizing oil yield and nutritional value.This review critically synthesizes recent findings on how rapeseed pretreatment modulates its signature lipid companions,contrasts conventional roasting with emerging pulsed-electric field,microwave and steam-explosion technologies,and evaluates their respective impacts on extraction efficiency,structural integrity and functional performance on phytosterols,polyphenols,tocopherols and carotenoids.It particularly compares and analyzes the extraction efficiency,cost-effectiveness,and environmental impact for these emerging technologies,and discusses the prospects for their integrated applications.Furthermore,the review concludes with the current research trends in pretreatment technology and offers insights into future research directions,aiming to provide scientific guidance for the high-quality processing of rapeseed and the production of rapeseed oil with high nutritional value.展开更多
Metal oxide catalysts are widely employed in propane dehydrogenation(PDH)for propylene synthesis,requiring sequential reduction-reaction-regeneration cycles.However,the eff ect of water present in the inlet gas or rea...Metal oxide catalysts are widely employed in propane dehydrogenation(PDH)for propylene synthesis,requiring sequential reduction-reaction-regeneration cycles.However,the eff ect of water present in the inlet gas or reactor on the catalytic per-formance of various metal oxides remains insuffi ciently understood.This study examines the infl uence of water on supported metal oxide catalysts,specifi cally CoO x/Al_(2)O_(3),VO x/Al_(2)O_(3),and an industrial analog CrO x/Al_(2)O_(3) catalyst.By combining titration experiments,in situ Fourier transform infrared spectroscopy,kinetic analysis,and isotopic techniques,we demon-strate that even trace amounts of water can markedly suppress PDH performance via dissociative adsorption on the oxide surface.Methanol pretreatment eff ectively scavenges adsorbed water,recovering Lewis acid-base sites and consequently restoring PDH activity.This work underscores the profound inhibitory role of trace water in PDH over metal oxide catalysts and illustrates the potential of methanol pretreatment as an effective strategy to mitigate this limitation.展开更多
The authors regret that due to negligence,the picture was misplaced in the original manuscript,resulting in Fig.6d being incorrectly included.The correct version of Fig.6d is provided below for reference.This error do...The authors regret that due to negligence,the picture was misplaced in the original manuscript,resulting in Fig.6d being incorrectly included.The correct version of Fig.6d is provided below for reference.This error does not affect the conclusions of the study,and we apologize for any confusion it may have caused.展开更多
Indonesia,with its vast forested regions,has experienced significant deforestation,adversely affecting the wood industry.As a result,alternative sources of lignocellulosic biomass are required to mitigate this impact....Indonesia,with its vast forested regions,has experienced significant deforestation,adversely affecting the wood industry.As a result,alternative sources of lignocellulosic biomass are required to mitigate this impact.Among the abundant lignocellulosic raw materials in Indonesia,particularly in Sumatra,bamboo stands out as a promising substitute.Bamboo is a highly versatile resource,suitable for various applications,including its use as a composite raw material to replace traditional wood-based products.This research work aimed to investigate and evaluate the characteristics—morphology,anatomy,physical and mechanical properties,chemical composition,starch content,and natural resistance—of three bamboo species:hitam bamboo(Gigantochloa atroviolacea),betung bamboo(Dendrocalamus asper),and belangke bamboo(Gigantochloa pruriens),as well as their suitability for the production of oriented strand boards(OSB).The lumen values of the bamboo samples ranged between 10 and 15μm,with hitam and betung bamboo exhibitingmedium-thickness cell walls(>5μm).Based on fiber dimension analysis,belangke,and betung bamboo are classified within quality class II,whereas hitam bamboo falls into class Ⅰ.The highest recorded tensile,shear,and compressive mechanical strength values were observed at the tips of hitam bamboo,measuring 563.43 MPa,15 MPa,and 6.87 kN/mm^(2),respectively.The bamboo samples underwent three different treatments:(1)immersion in water for 24 h,(2)autoclaving at 120℃ for 1 h,and(3)a control group with no treatment.OSB panels were produced with dimensions of 20 cm×20 cm×1 cm(length×width×thickness)using isocyanate adhesive and conditioned for 14 days.The physical and mechanical properties of the OSBs were evaluated based on the Japan Industrial Standard(JIS)A5908:2003 and theCanadian StandardsAssociation(CSA)0437.0:2011 criteria.The density of the laboratory-produced OSB panels ranged from 0.60 to 0.73 g/cm^(3),moisture content varied from5.4% to 8.1%,water absorption ranged between 31.6% and 45.8%,and thickness swelling was recorded at 5.1% to 16.3%.The modulus of elasticity(MOE)ranged from2745.1 to 7813.3 MPa,themodulus of rupture(MOR)from 30.8 to 58.8MPa,and internal bonding(IB)from 0.27 to 0.47 MPa.Overall,all OSB panels produced in this study met the specifications outlined in JIS A 5908(2003)and CSA 0437.0(2011),demonstrating the viability of these bamboo species as raw materials for OSB production.展开更多
Hydrogen-induced cracking (HIC) is one of the most complex material problems that hydrogen can diffuse into and interact with microstructure, degrading their mechanical properties. Microstructural modification is an e...Hydrogen-induced cracking (HIC) is one of the most complex material problems that hydrogen can diffuse into and interact with microstructure, degrading their mechanical properties. Microstructural modification is an effective way to enhance the resistance to HIC. The present study focused on the relationship between the retained austenite (RA) and HIC behavior in NiCrMoV/Nb multi-alloying ultra-strength steel. Results demonstrated that the maximum volume fraction of RA of 9.31% was obtained for QL30T specimen. After the deep cryogenic pretreatment, the volume fraction of RA reduced to 8.8%. RA could reduce the effective diffusion coefficient, while deep cryogenic pretreatment increased the susceptibility of the steel to HIC by a maxim of 14.8%. This was mainly due to the transformation of retained austenite into martensite, degrading the mechanical properties under hydrogen-charged condition. In addition, the deep cryogenic pretreatment had a significant effect on the crack initiation and propagation, with the intergranular (IG) fracture becoming the dominant fracture mode where an increase in the number of secondary cracks in the section. The interfaces of RA and matrix, as well as the grain boundaries, were the preferred sites for cracks initiation.展开更多
Developing greener lignocellulose pretreatment method is one of the important issues in the biomass refining process.This work aims to investigate a recyclable Cu_(2)O/H_(2)O_(2)catalytic pretreatment method for impro...Developing greener lignocellulose pretreatment method is one of the important issues in the biomass refining process.This work aims to investigate a recyclable Cu_(2)O/H_(2)O_(2)catalytic pretreatment method for improving synthesis efficiency of aviation fuel from lignocellulosic biomass.The Cu_(2)O/H_(2)O_(2)catalytic pretreatment dramatically facilitated the preparation of ethanol intermediate and bioaviation fuel.Lignocellulosic biomass pretreated by Cu_(2)O/H_(2)O_(2)showed higher ethanol yield(33.8%).For the synthesis process of aviation fuel,ethanol conversion of 93.1%and aviation fuel selectivity of 70.8%were achieved.On the basis of catalyst characterization,biomass characterization and free radical detection,probable function and mechanism of Cu_(2)O/H_(2)O_(2)catalytic pretreatment were proposed.The cuprous oxide catalyst promoted the formation of hydroxyl radicals,thereby facilitating depolymerization of lignocellulose.Ulteriorly,Cu_(2)O/H_(2)O_(2)catalytic pretreatment enhanced the saccharification of lignocellulosic biomass,which was beneficial for the formation of ethanol intermediate and the production of biofuel.展开更多
To improve the activity of Co/Al_(2)O_(3)catalysts in selective catalytic oxidation of ammonia(NH_(3)-SCO),valence state and size of active centers of Al_(2)O_(3)-supported Co catalysts were adjusted by conducting H_(...To improve the activity of Co/Al_(2)O_(3)catalysts in selective catalytic oxidation of ammonia(NH_(3)-SCO),valence state and size of active centers of Al_(2)O_(3)-supported Co catalysts were adjusted by conducting H_(2)reduction pretreatment.The NH_(3)-SCO activity of the adjusted 2Co/Al_(2)O_(3)catalyst was substantially improved,outperforming other catalysts with higher Co-loading.Fresh Co/Al_(2)O_(3)catalysts exhibited multitemperature reduction processes,enabling the control of the valence state of the Co-active centers by adjusting the reduction temperature.Changes in the state of the Co-active centers also led to differences in redox capacity of the catalysts,resulting in different reaction mechanisms for NH_(3)-SCO.However,in situ diffuse reflectance infrared Fourier transform spectra revealed that an excessive O_(2)activation capacity caused overoxidation of NH_(3)to NO and NO_(2).The NH_(3)-SCO activity of the 2Co/Al_(2)O_(3)catalyst with low redox capacity was successfully increased while controlling and optimizing the N_(2)selectivity by modulating the active centers via H_(2)pretreatment,which is a universalmethod used for enhancing the redox properties of catalysts.Thus,this method has great potential for application in the design of inexpensive and highly active catalysts.展开更多
The ammonium salt precipitation method is frequently utilized for extracting vanadium from the leaching solution obtained through sodium roasting of vanadium slag.However,Na^(+)and NH_(4)^(+)ions in the vanadium preci...The ammonium salt precipitation method is frequently utilized for extracting vanadium from the leaching solution obtained through sodium roasting of vanadium slag.However,Na^(+)and NH_(4)^(+)ions in the vanadium precipitation solution can not be effectively separated,leading to a large amount of ammonia-nitrogen wastewater which is difficult to treat.In this study,the manganese salt pretreatment process is used to extract vanadium from a sodium roasting leaching solution,enabling the separation of vanadium and sodium.The vanadium extraction product of manganese salt is dissolved in acid to obtain vanadium-containing leaching solution,then vanadium is extracted by hydrolysis and vanadium precipitation,and V_(2)O_(5)is obtained after impurity removal and calcination.The results show that the rate of vanadium extraction by manganese salt is 98.23%.The vanadium extraction product by manganese salt is Mn_(2)V_(2)O_(7),and its sodium content is only 0.167%.Additionally,the acid solubility of vanadium extraction products by manganese salt is 99.52%,and the vanadium precipitation rate of manganese vanadate solution is 92.34%.After the removal of manganese and calcination process,the purity of V_(2)O_(5)product reached 97.73%,with a mere 0.64%loss of vanadium.The Mn_(2)^(+)and NH_(4)^(+)ions in the solution after vanadium precipitation are separated by precipitation method,which reduces the generation of ammonia-nitrogen wastewater.This is conducive to the green and sustainable development of the vanadium industry.展开更多
The coating material is considered as the key of solid-phase microextraction(SPME)due to the fact that which has much effect on the selectivity and sensitivity of the analytical method.Herein,the porous hollow carbon ...The coating material is considered as the key of solid-phase microextraction(SPME)due to the fact that which has much effect on the selectivity and sensitivity of the analytical method.Herein,the porous hollow carbon nanospheres(PHCNs)were synthesized by selectively removing the interior part of solid inhomogeneous nanospheres with acetone.Using PHCNs as new coating material,a SPME fiber was prepared.To the best of our knowledge,PHCNs was utilized as a SPME fiber coating for the first time.The fiber coating material PHCNs demonstrated excellent thermal stability(>800℃)and long usage lifespan(≥60 times).A headspace SPME(HS-SPME)was established to non-contact extract and enrich polycyclic aromatic hydrocarbons(PAHs)prior to gas chromatography-flame ionization detector(GC-FID)analysis.The HS-SPME not only can eliminate non-volatile interferences from matrix,but also be able to protect fiber coating and prolong lifespan of fiber prober.The linearity in the linear range of 0.01-30 ng/m L and limits of detection from 0.003 ng/mL to 0.006 ng/mL were obtained by HS-SPME-GC-FID with PHCNs as fiber coating.The enrichment factors were calculated as 5420-9211 compared with conventional direct introduce analysis.The spiked recoveries of real samples including campus lake water and lime tree honey were obtained from 80.93%to 118.0%with relative standard deviation no higher than 10.6%.The π-π stacking interaction,CH/π interaction,and unique built-in cavities significantly enhance the extraction performance of PHCNs coating fiber to PAHs.This work demonstrated that the PHCNs as fiber coating materials present good application prospects for the extraction and enrichment of trace PAHs from complex matrixes.展开更多
[ Objective] The aim was to study pretreatment of ultrasound enhancing dilute H2SO4 on cellulase activity of corn straw liquid fermentation and explore the pretretment＇ s optimal conditions. [ Method ] By using ortho...[ Objective] The aim was to study pretreatment of ultrasound enhancing dilute H2SO4 on cellulase activity of corn straw liquid fermentation and explore the pretretment＇ s optimal conditions. [ Method ] By using orthogonal test, the pretretment of ultrasound enhancing dilute H2SO4 on corn straw was studied, then straw was fermented as the sole carbon source. Finally, the cellulase activity in extracellular fermentation broth was determined. [Result] The results showed that cellulase activity in extracellular broth was greatest under the conditions of acid bath time 3 h, acid concentration 3.5%, ultrasonic power 150 W, and ultrasonic time 5 h. They were FPA 15.82 U/ml, Cx 39.9 U/ml, 13-Giu 55.94 U/ml respectively. [ Conclusion] Under the above conditions, extracellular cellulase production has a high stability.展开更多
Pretreated Mg-Li alloy sheets were pre-plated in a NiCO3？2Ni（OH）2？4H2O solution to form a thin Ni-P alloy film and then plating in a NiSO4？6H2O solution was carried out to obtain a protective coating.The surface ...Pretreated Mg-Li alloy sheets were pre-plated in a NiCO3？2Ni（OH）2？4H2O solution to form a thin Ni-P alloy film and then plating in a NiSO4？6H2O solution was carried out to obtain a protective coating.The surface morphology,structure and corrosion resistance of the coating were studied.The results showed that a flat,bright and compact plating layer,which was integrated into the matrix metal,was obtained.The P content of the Ni-P coating reached 13.56%（mass fraction）.The hardness value of the Ni-P coating was about HV 549.The polarization curve showed that the corrosion potential of the Ni-P coating reached ？0.249 V（vs SCE）.A long passivation region was found on the polarization curve,and this phenomenon indicated that the coating has an excellent anti-corrosion property.展开更多
基金Supported by Tangshan Science and Technology Planning Project(25150202E).
文摘In recent years,the problem of veterinary drug residues in animal-derived foods has attracted worldwide attention.Developing rapid,simple,highly sensitive,and high-throughput veterinary drug residue detection technologies has become an urgent need.This paper provides a comprehensive review of the pretreatment and analytical techniques for veterinary drug residue analysis,comparing the detection principles,operational procedures,and respective advantages and disadvantages of various detection technologies.It further explores the future development directions of veterinary drug residue detection technologies.
基金supported by the Transportation Science and Technology Program of Henan Province(grant number:2023-4-2)the Key Research and Development Program of Ningxia Science and Technology Department(grant number:2022BEG02008)+2 种基金China Communications Construction Group Co.,Ltd.Science and Technology R&D Project(grant number:2021KJW02)the Research and Development Program of Henan Transportation Investment Group Co.,Ltd.(grant number:HNJT2025-1-9)the Postdoctoral Fellowship Program of CPSF(grand number:GZC20251139).
文摘The addition of high-content crumb rubber(HCCR)in asphalt can effectively address waste tire pollution and provide sustainable environmental and economic advantages.However,the practical application of conventional rubberized binders is significantly limited by high viscosity and poor storage stability.To address these issues,researchers have pretreated crumb rubber(CR)with oil,but high-temperature performance remains insufficient.Therefore,this study aimed to optimize the viscosity,storage stability,and rheological properties of high-content crumb rubber-modified asphalt(HCCRMA)by varying the pretreatment levels of CR and incorporating various additives,including styrene-butadiene-styrene(SBS),deoiled asphalt(DA),or recycled low-density polyethylene(RLDPE).In addition,CR was pretreated with waste cooking oil(WCO)at various ratios,pre-swelling temperatures,and times.The results show that DA exhibits excellent storage stability and lower viscosity compared with other modifiers in HCCRMA,and the 4%RLDPE with pretreated HCCR has the greatest high-temperature rutting resistance.The inclusion of RLDPE increases the stiffness and elasticity of the modified asphalt,which results in greater high-temperature performance.Additionally,the fluorescence microscopy(FM)test confirms that SBS exhibits better dispersion than other modifiers and forms a more homogeneous phase separation in the HCCRMA.All in all,this research achieved an optimal balance of storage stability and rheological properties in asphalt modified with pretreated HCCR and 6%SBS,which provides a valuable reference for performance improvement of HCCR-modified binders.
基金supported by the Crohn's&Colitis Foundation Senior Research Award(No.902766 to J.S.)The National Institute of Diabetes and Digestive and Kidney Diseases(No.R01DK105118-01 and R01DK114126 to J.S.)+1 种基金United States Department of Defense Congressionally Directed Medical Research Programs(No.BC191198 to J.S.)VA Merit Award BX-19-00 to J.S.
文摘Metabolomics as a research field and a set of techniques is to study the entire small molecules in biological samples.Metabolomics is emerging as a powerful tool generally for pre-cision medicine.Particularly,integration of microbiome and metabolome has revealed the mechanism and functionality of microbiome in human health and disease.However,metabo-lomics data are very complicated.Preprocessing/pretreating and normalizing procedures on metabolomics data are usually required before statistical analysis.In this review article,we comprehensively review various methods that are used to preprocess and pretreat metabolo-mics data,including MS-based data and NMR-based data preprocessing,dealing with zero and/or missing values and detecting outliers,data normalization,data centering and scaling,data transformation.We discuss the advantages and limitations of each method.The choice for a suitable preprocessing method is determined by the biological hypothesis,the characteristics of the data set,and the selected statistical data analysis method.We then provide the perspective of their applications in the microbiome and metabolome research.
基金financial support by the National Natural Science Foundation of China(No.52374293)Zhongyuan Science and Technology Innovation Leading Talent Project,China(No.224200510025)+1 种基金the Science and Technology Innovation Program of Hunan Province,China(No.2022RC1123)One of the authors,Hong-bo ZENG,gratefully acknowledges the support from the Natural Sciences and Engineering Research Council of Canada(NSERC)and the Canada Research Chairs Program.
文摘Lithium-ion batteries(LIBs)are the most popular energy storage devices due to their high energy density,high operating voltage,and long cycle life.However,green and effective recycling methods are needed because LIBs contain heavy metals such as Co,Ni,and Mn and organic compounds inside,which seriously threaten human health and the environment.In this work,we review the current status of spent LIB recycling,discuss the traditional pyrometallurgical and hydrometallurgical recovery processes,and summarize the existing short-process recovery technologies such as salt-assisted roasting,flotation processes,and direct recycling.Finally,we analyze the problems and potential research prospects of the current recycling process,and point out that the multidisciplinary integration of recycling will become the mainstream technology for the development of spent LIBs.
基金Project(BGRIMM-KJSKL-2024-07) supported by the Open Foundation of State Key Laboratory of Mineral Processing,ChinaProjects(52374259,52174239) supported by the National Natural Science Foundation of China。
文摘Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surface pretreatment experiments with citric acid,tartaric acid,and tannic acid(TA)on magnesite and dolomite as well as flotation experiments on pretreated samples were performed in this study.Experimental results demonstrated that when citric acid and tartaric acid are used for surface pretreatment,the separation effect of magnesite and dolomite is poor.However,when TA is used,the separation effect of magnesite and dolomite improves.SEM and BET analysis indicated that surface pretreatment with TA changes the surface morphology of the two minerals,resulting in additional concave pores on the dolomite surface,and a significant increase in pore size and specific surface area.The adsorption quantity test and contact angle measurement demonstrated that after surface pretreatment with TA,the magnesite adsorption capacity on sodium oleate(NaOL)slightly decreases and the dolomite adsorption capacity on NaOL considerably decreases.XPS detection concluded that the surface pretreatment of TA on the magnesite surface mainly relies on physical adsorption with weak adsorption ability and poor ability to act on Mg sites.The TA surface pretreatment action on the dolomite surface is mainly through chemical adsorption,and it is strongly and selectively adsorbed on the Ca site of dolomite through O.Actual ore rough selection experiments reveal that TA pretreatment successfully removes dolomite from magnesite,resulting in a high-quality magnesite concentrate characterized by a MgO grade of 45.49%and a CaO grade of 0.75%.
基金Funding was provided by the US Department of Agriculture-Agricultural Research Service and the University of Nebraska Agricultural Research Division.
文摘The aim of this work was to evaluate the use of stover from brown midrib(bmr)grain sorghum to produce polyhydroxyalkanoates(PHAs).These mutants produce lignin with novel compositions and/or reduced lignin content that was hypothesized to result in higher PHA production than when using a wild-type sorghum stover.Five sorghum stover samples[wild-type(control)and four bmr mutants[bmr2,bmr6,and bmr12,and a double bmr mutant:bmr6 and bmr12(stacked)]were evaluated as substrates for poly(3-hydroxybutyrate)(P(3HB))production.When the main sugars in non-detoxified alkali-pretreated sorghum stover hydrolysates(SSHs)were metabolized by Paraburkholderia sacchari for P(3HB)production,the SSHs from bmr plants were demonstrated to be promising feedstocks with a maximum P(3HB)concentration of 7.2 g/L from the bmr6 SSH,while a maximum P(3HB)concentration of 4.2 g/L P(3HB)was produced using wild-type SSH.Moreover,the highest maximum Y_([P(3HB)/sugars])were achieved using stacked SSH and bmr12 SSH(0.44 g/g and 0.42 g/g,respectively).Furthermore,Cuprivadus necator was utilized to evaluate P(3HB)synthesis from the alkaline pretreated liquor(APL)remaining after sorghum stover pretreatment and an oxidative enzyme-mediator-surfactant system(OEMS)was used to improve P(3HB)production from the APLs.A 28-fold increase in PHB production from the bmr2-APL with OEMS compared to the fermentation of the same APL with no OEMS was observed.This is the first published report to use grain sorghum stover to produce polyhydroxyalkanoates(PHAs).Also,a novel combination of PHA production from both sugars and lignin is reported.
基金supported by the National Key Research and Development Project (Nos.2020YFC1908702 and 2021YFC3200700)the National Natural Science Foundation of China (Nos.52192684 and 52192680).
文摘Sewage sludge in cities of Yangzi River Belt,China,generally exhibits a lower organic content and higher silt contentdue to leakage of drainage system,which caused low bioenergy recovery and carbon emission benefits in conventional anaerobic digestion(CAD).Therefore,this paper is on a pilot scale,a bio-thermophilic pretreatment anaerobic digestion(BTPAD)for low organic sludge(volatile solids(VS)of 4%)was operated with a long-term continuous flow of 200 days.The VS degradation rate and CH_(4) yield of BTPAD increased by 19.93%and 53.33%,respectively,compared to those of CAD.The analysis of organic compositions in sludge revealed that BTPAD mainly improved the hydrolysis of proteins in sludge.Further analysis of microbial community proportions by high-throughput sequencing revealed that the short-term bio-thermophilic pretreatment was enriched in Clostridiales,Coprothermobacter and Gelria,was capable of hydrolyzing acidified proteins,and provided more volatile fatty acid(VFA)for the subsequent reaction.Biome combined with fluorescence quantitative polymerase chain reaction(PCR)analysis showed that the number of bacteria with high methanogenic capacity in BTPAD was much higher than that in CAD during the medium temperature digestion stage,indicating that short-term bio-thermophilic pretreatment could provide better methanogenic conditions for BTPAD.Furthermore,the greenhouse gas emission footprint analysis showed that short-term bio-thermophilic pretreatment could reduce the carbon emission of sludge anaerobic digestion system by 19.18%.
基金funded by the Latvian State Institute of Wood Chemistry Bioeconomic Research Grant No.09-24 titled“Selective Valorization of Lignocellulosic Biomass(SeVaLi)”.
文摘Oat husks,a byproduct of oat milling operations with limited economic value,present a promising feedstock for biorefinery processes due to their chemical composition.This study investigates the conversion of C5 carbohydrates in oat husks into furfural through hydrothermal pretreatment using various phosphate-based catalysts,including H_(3)PO_(4),NH_(4)H_(2)PO_(4),NaH_(2)PO_(4),KH_(2)PO_(4),K_(2)HPO_(4) and K_(3)PO_(4) as catalyst.The catalysts’effectiveness in promoting furfural production was evaluated under identical hydrothermal conditions(treatment time for 60 min at a constant temperature of 170℃ and a catalyst amount).Continuous water steam was used to strip furfural from the reaction zone and minimize its degradation.Results indicated that H_(3)PO_(4) was the most effective catalyst,achieving a furfural yield of 13.99 wt.%,which corresponds to approximately 57%of the theoretical yield.NH4H2PO4 also showed moderate effectiveness,while sodium and potassium phosphate salts were significantly less effective.A scanning electron microscope analysis shows that catalysts with lower pH may disrupt the oat husks external layer thus providing a higher C5 carbohydrates conversion rate into furfural.The chemical complexity of oat husk contributes to side reactions between its carbohydrates and lignin during the hydrothermal treatment.This results in an increase in acid-insoluble lignin and inorganic matter in the oat husk lignocellulosic residue,which can reduce the effectiveness of further cellulose saccharification by enzymatic hydrolysis.
基金funded by the National Natural Science Foundation of China(22278189,22478154)the Fundamental Research Funds for the Central Universities(Jiangnan University,JUSRP202501024)the Priority Academic Program Development of Jiangsu Higher Education Institutions,the 111 Project(No.111-2-06)。
文摘The increasing demand for sustainable energy solutions necessitates innovative approaches to biomass utilization.This study introduces a comprehensive biorefinery model that valorizes poplar biomass into high-value products,including ethanol,furfural,phenol,and biochar.These products not only serve as promising sources for biofuel and renewable chemicals but also contribute to pollution mitigation.The approach employs a biphasic pretreatment system utilizing p-toluenesulfonic acid,pentanol,and AlCl_(3) under optimized conditions(120℃ for 45 min),achieving remarkable efficiencies of 95.8%xylan removal,90.2%delignification,and 90.7%glucan recovery.The underlying mechanism,elucidated through density functional theory,demonstrates how the disruption of lignin-carbohydrate complexes via electrostatic and hydrogen-bonding interactions enhances product yields.The cellulose-rich substrate yielded 71.3 g/L ethanol,while solubilized xylan converted to 86.7%furfural without additional acid.Furthermore,lignin pyrolysis produced bio-oil containing over 45.2%phenolic compounds,while biochar demonstrated significant adsorptive capacity for perfluorooctanoic acid.Scaling this biorefinery model to process 140 million tons of poplar biomass annually reduces CO_(2)emissions by 75.3 million tons and provides socioeconomic savings of $17.3 billion,supporting sustainable industrial transformation.
基金funded by National Key R&D Program Key Special Project(Grant No.2024YFF1106100)National Natural Science Foundation of China(Grant No.32472446 and 22301313)+4 种基金Hubei Provincial Technology Innovation Project(Grant No.2024BBB084)Hubei Provincial Science and Technology Project(Grant No.2025BBB065)Innovation group project of Hubei Province(Grant No.2023AFA042)Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(Grant No.CAAS-ASTIP-2021-OCRI)Hubei Young sci-tech Talen Funding Project(E Kexieban 2025[67])。
文摘Rapeseed is the primary domestic source of edible vegetable oil in China.Its oil is naturally rich in phytosterols,polyphenols,tocopherols,carotenoids and other lipid-soluble companions,which are highly beneficial to human health.Since the content and bioaccessibility of these health-promoting companions are mostly locked during the first post-harvest operation,the pretreatment technology has become the decisive lever for simultaneously maximizing oil yield and nutritional value.This review critically synthesizes recent findings on how rapeseed pretreatment modulates its signature lipid companions,contrasts conventional roasting with emerging pulsed-electric field,microwave and steam-explosion technologies,and evaluates their respective impacts on extraction efficiency,structural integrity and functional performance on phytosterols,polyphenols,tocopherols and carotenoids.It particularly compares and analyzes the extraction efficiency,cost-effectiveness,and environmental impact for these emerging technologies,and discusses the prospects for their integrated applications.Furthermore,the review concludes with the current research trends in pretreatment technology and offers insights into future research directions,aiming to provide scientific guidance for the high-quality processing of rapeseed and the production of rapeseed oil with high nutritional value.
基金supported by the National Key R&D Program of China(No.2023YFA1507800)the National Science Foundation of China(Nos.22121004,22122808,22478279,and 22108201)+1 种基金the Haihe Laboratory of Sustainable Chemical Trans-formations,the Program of Introducing Talents of Discipline to Uni-versities(No.BP0618007)the XPLORER PRIZE.
文摘Metal oxide catalysts are widely employed in propane dehydrogenation(PDH)for propylene synthesis,requiring sequential reduction-reaction-regeneration cycles.However,the eff ect of water present in the inlet gas or reactor on the catalytic per-formance of various metal oxides remains insuffi ciently understood.This study examines the infl uence of water on supported metal oxide catalysts,specifi cally CoO x/Al_(2)O_(3),VO x/Al_(2)O_(3),and an industrial analog CrO x/Al_(2)O_(3) catalyst.By combining titration experiments,in situ Fourier transform infrared spectroscopy,kinetic analysis,and isotopic techniques,we demon-strate that even trace amounts of water can markedly suppress PDH performance via dissociative adsorption on the oxide surface.Methanol pretreatment eff ectively scavenges adsorbed water,recovering Lewis acid-base sites and consequently restoring PDH activity.This work underscores the profound inhibitory role of trace water in PDH over metal oxide catalysts and illustrates the potential of methanol pretreatment as an effective strategy to mitigate this limitation.
文摘The authors regret that due to negligence,the picture was misplaced in the original manuscript,resulting in Fig.6d being incorrectly included.The correct version of Fig.6d is provided below for reference.This error does not affect the conclusions of the study,and we apologize for any confusion it may have caused.
基金supported by the TALENTA research grant scheme of the“Kolaborasi Nasional Penerima Dana Hibah WCU(World Class University)Universitas Sumatera Utara”in the year 2022(Number:353/UN5.2.3.1/PPM/KP-TALENTA/2022)supported by the project“Development,Exploitation Properties and Application of Eco-Friendly Wood-Based Composites from Alternative Lignocellulosic Raw Materials”,Project No.HHC-b-1290/19.10.2023,carried out at the University of Forestry,Sofia,Bulgaria.
文摘Indonesia,with its vast forested regions,has experienced significant deforestation,adversely affecting the wood industry.As a result,alternative sources of lignocellulosic biomass are required to mitigate this impact.Among the abundant lignocellulosic raw materials in Indonesia,particularly in Sumatra,bamboo stands out as a promising substitute.Bamboo is a highly versatile resource,suitable for various applications,including its use as a composite raw material to replace traditional wood-based products.This research work aimed to investigate and evaluate the characteristics—morphology,anatomy,physical and mechanical properties,chemical composition,starch content,and natural resistance—of three bamboo species:hitam bamboo(Gigantochloa atroviolacea),betung bamboo(Dendrocalamus asper),and belangke bamboo(Gigantochloa pruriens),as well as their suitability for the production of oriented strand boards(OSB).The lumen values of the bamboo samples ranged between 10 and 15μm,with hitam and betung bamboo exhibitingmedium-thickness cell walls(>5μm).Based on fiber dimension analysis,belangke,and betung bamboo are classified within quality class II,whereas hitam bamboo falls into class Ⅰ.The highest recorded tensile,shear,and compressive mechanical strength values were observed at the tips of hitam bamboo,measuring 563.43 MPa,15 MPa,and 6.87 kN/mm^(2),respectively.The bamboo samples underwent three different treatments:(1)immersion in water for 24 h,(2)autoclaving at 120℃ for 1 h,and(3)a control group with no treatment.OSB panels were produced with dimensions of 20 cm×20 cm×1 cm(length×width×thickness)using isocyanate adhesive and conditioned for 14 days.The physical and mechanical properties of the OSBs were evaluated based on the Japan Industrial Standard(JIS)A5908:2003 and theCanadian StandardsAssociation(CSA)0437.0:2011 criteria.The density of the laboratory-produced OSB panels ranged from 0.60 to 0.73 g/cm^(3),moisture content varied from5.4% to 8.1%,water absorption ranged between 31.6% and 45.8%,and thickness swelling was recorded at 5.1% to 16.3%.The modulus of elasticity(MOE)ranged from2745.1 to 7813.3 MPa,themodulus of rupture(MOR)from 30.8 to 58.8MPa,and internal bonding(IB)from 0.27 to 0.47 MPa.Overall,all OSB panels produced in this study met the specifications outlined in JIS A 5908(2003)and CSA 0437.0(2011),demonstrating the viability of these bamboo species as raw materials for OSB production.
文摘Hydrogen-induced cracking (HIC) is one of the most complex material problems that hydrogen can diffuse into and interact with microstructure, degrading their mechanical properties. Microstructural modification is an effective way to enhance the resistance to HIC. The present study focused on the relationship between the retained austenite (RA) and HIC behavior in NiCrMoV/Nb multi-alloying ultra-strength steel. Results demonstrated that the maximum volume fraction of RA of 9.31% was obtained for QL30T specimen. After the deep cryogenic pretreatment, the volume fraction of RA reduced to 8.8%. RA could reduce the effective diffusion coefficient, while deep cryogenic pretreatment increased the susceptibility of the steel to HIC by a maxim of 14.8%. This was mainly due to the transformation of retained austenite into martensite, degrading the mechanical properties under hydrogen-charged condition. In addition, the deep cryogenic pretreatment had a significant effect on the crack initiation and propagation, with the intergranular (IG) fracture becoming the dominant fracture mode where an increase in the number of secondary cracks in the section. The interfaces of RA and matrix, as well as the grain boundaries, were the preferred sites for cracks initiation.
基金supported by the National Natural Science Foundation of China(No.U21A20288)。
文摘Developing greener lignocellulose pretreatment method is one of the important issues in the biomass refining process.This work aims to investigate a recyclable Cu_(2)O/H_(2)O_(2)catalytic pretreatment method for improving synthesis efficiency of aviation fuel from lignocellulosic biomass.The Cu_(2)O/H_(2)O_(2)catalytic pretreatment dramatically facilitated the preparation of ethanol intermediate and bioaviation fuel.Lignocellulosic biomass pretreated by Cu_(2)O/H_(2)O_(2)showed higher ethanol yield(33.8%).For the synthesis process of aviation fuel,ethanol conversion of 93.1%and aviation fuel selectivity of 70.8%were achieved.On the basis of catalyst characterization,biomass characterization and free radical detection,probable function and mechanism of Cu_(2)O/H_(2)O_(2)catalytic pretreatment were proposed.The cuprous oxide catalyst promoted the formation of hydroxyl radicals,thereby facilitating depolymerization of lignocellulose.Ulteriorly,Cu_(2)O/H_(2)O_(2)catalytic pretreatment enhanced the saccharification of lignocellulosic biomass,which was beneficial for the formation of ethanol intermediate and the production of biofuel.
基金supported by the National Natural Science Foundation of China(No.52260013)Yunnan Major Scientific and Technological Projects(No.202202AG050005).
文摘To improve the activity of Co/Al_(2)O_(3)catalysts in selective catalytic oxidation of ammonia(NH_(3)-SCO),valence state and size of active centers of Al_(2)O_(3)-supported Co catalysts were adjusted by conducting H_(2)reduction pretreatment.The NH_(3)-SCO activity of the adjusted 2Co/Al_(2)O_(3)catalyst was substantially improved,outperforming other catalysts with higher Co-loading.Fresh Co/Al_(2)O_(3)catalysts exhibited multitemperature reduction processes,enabling the control of the valence state of the Co-active centers by adjusting the reduction temperature.Changes in the state of the Co-active centers also led to differences in redox capacity of the catalysts,resulting in different reaction mechanisms for NH_(3)-SCO.However,in situ diffuse reflectance infrared Fourier transform spectra revealed that an excessive O_(2)activation capacity caused overoxidation of NH_(3)to NO and NO_(2).The NH_(3)-SCO activity of the 2Co/Al_(2)O_(3)catalyst with low redox capacity was successfully increased while controlling and optimizing the N_(2)selectivity by modulating the active centers via H_(2)pretreatment,which is a universalmethod used for enhancing the redox properties of catalysts.Thus,this method has great potential for application in the design of inexpensive and highly active catalysts.
基金supported by the National Natural Science Foundation of China(52204309,52374300 and 52174277)the Opening Foundation of State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization,China(2022P4FZG11A).
文摘The ammonium salt precipitation method is frequently utilized for extracting vanadium from the leaching solution obtained through sodium roasting of vanadium slag.However,Na^(+)and NH_(4)^(+)ions in the vanadium precipitation solution can not be effectively separated,leading to a large amount of ammonia-nitrogen wastewater which is difficult to treat.In this study,the manganese salt pretreatment process is used to extract vanadium from a sodium roasting leaching solution,enabling the separation of vanadium and sodium.The vanadium extraction product of manganese salt is dissolved in acid to obtain vanadium-containing leaching solution,then vanadium is extracted by hydrolysis and vanadium precipitation,and V_(2)O_(5)is obtained after impurity removal and calcination.The results show that the rate of vanadium extraction by manganese salt is 98.23%.The vanadium extraction product by manganese salt is Mn_(2)V_(2)O_(7),and its sodium content is only 0.167%.Additionally,the acid solubility of vanadium extraction products by manganese salt is 99.52%,and the vanadium precipitation rate of manganese vanadate solution is 92.34%.After the removal of manganese and calcination process,the purity of V_(2)O_(5)product reached 97.73%,with a mere 0.64%loss of vanadium.The Mn_(2)^(+)and NH_(4)^(+)ions in the solution after vanadium precipitation are separated by precipitation method,which reduces the generation of ammonia-nitrogen wastewater.This is conducive to the green and sustainable development of the vanadium industry.
基金supported by National Natural Science Foundation of China(No.22376053)supported by the Natural Science Foundation of Henan Province,China(No.242300421034)Henan Key Scientific Research Programs to Universities and Colleges(No.22ZX003)。
文摘The coating material is considered as the key of solid-phase microextraction(SPME)due to the fact that which has much effect on the selectivity and sensitivity of the analytical method.Herein,the porous hollow carbon nanospheres(PHCNs)were synthesized by selectively removing the interior part of solid inhomogeneous nanospheres with acetone.Using PHCNs as new coating material,a SPME fiber was prepared.To the best of our knowledge,PHCNs was utilized as a SPME fiber coating for the first time.The fiber coating material PHCNs demonstrated excellent thermal stability(>800℃)and long usage lifespan(≥60 times).A headspace SPME(HS-SPME)was established to non-contact extract and enrich polycyclic aromatic hydrocarbons(PAHs)prior to gas chromatography-flame ionization detector(GC-FID)analysis.The HS-SPME not only can eliminate non-volatile interferences from matrix,but also be able to protect fiber coating and prolong lifespan of fiber prober.The linearity in the linear range of 0.01-30 ng/m L and limits of detection from 0.003 ng/mL to 0.006 ng/mL were obtained by HS-SPME-GC-FID with PHCNs as fiber coating.The enrichment factors were calculated as 5420-9211 compared with conventional direct introduce analysis.The spiked recoveries of real samples including campus lake water and lime tree honey were obtained from 80.93%to 118.0%with relative standard deviation no higher than 10.6%.The π-π stacking interaction,CH/π interaction,and unique built-in cavities significantly enhance the extraction performance of PHCNs coating fiber to PAHs.This work demonstrated that the PHCNs as fiber coating materials present good application prospects for the extraction and enrichment of trace PAHs from complex matrixes.
基金Supported by the National Key Technology R&D Program during the11~(th)five-year Plan(2007BAD34B03)the Important Project of Ministryof Education(107127)Scientific Research Foundation ofHefei University of Technology(113-036404)~~
文摘[ Objective] The aim was to study pretreatment of ultrasound enhancing dilute H2SO4 on cellulase activity of corn straw liquid fermentation and explore the pretretment＇ s optimal conditions. [ Method ] By using orthogonal test, the pretretment of ultrasound enhancing dilute H2SO4 on corn straw was studied, then straw was fermented as the sole carbon source. Finally, the cellulase activity in extracellular fermentation broth was determined. [Result] The results showed that cellulase activity in extracellular broth was greatest under the conditions of acid bath time 3 h, acid concentration 3.5%, ultrasonic power 150 W, and ultrasonic time 5 h. They were FPA 15.82 U/ml, Cx 39.9 U/ml, 13-Giu 55.94 U/ml respectively. [ Conclusion] Under the above conditions, extracellular cellulase production has a high stability.
基金Projects(50974114,51174060) supported by National Natural Science Foundation of ChinaProject(2008AA03Z512) supported by High-tech Research and Development Program of ChinaProject(20070145049) supported by PhD Programs Foundation of Ministry of Education of China
文摘Pretreated Mg-Li alloy sheets were pre-plated in a NiCO3？2Ni（OH）2？4H2O solution to form a thin Ni-P alloy film and then plating in a NiSO4？6H2O solution was carried out to obtain a protective coating.The surface morphology,structure and corrosion resistance of the coating were studied.The results showed that a flat,bright and compact plating layer,which was integrated into the matrix metal,was obtained.The P content of the Ni-P coating reached 13.56%（mass fraction）.The hardness value of the Ni-P coating was about HV 549.The polarization curve showed that the corrosion potential of the Ni-P coating reached ？0.249 V（vs SCE）.A long passivation region was found on the polarization curve,and this phenomenon indicated that the coating has an excellent anti-corrosion property.
