Study on the green extraction of corncob xylan by deep eutectic solvent

Corn as one of the world's major food crops,its by-product corn cob is also rich in resources.However,the unreasonable utilization of corn cob often causes the environmental pollution,waste of resources and other problems.As one of the most abundant polymers in nature,xylan is widely used in food,medicine,materials and other fields.Corn cob is rich in xylan,which is an ideal raw material for extracting xylan.However,the intractable lignin is covalently linked to xylan,which increases the difficulty of xylan extraction.It has been reported that the deep eutectic solvent(DES)could preferentially dissolve lignin in biomass,thereby dissolving the xylan.Then,the xylan in the extract was separated by ethanol precipitation method.The xylan precipitate was obtained after centrifugation,while the supernatant was retained.The components of the supernatant after ethanol precipitation were separated by the rotary evaporator.The ethanol,water and DES were collected for the subsequent extraction of corn cob xylan.In this study,a novel way was provided for the green production of corn cob xylan.The DES was used to extract xylan from corn cob which was used as the raw material.The effects of solid-liquid ratio,reaction time,reaction temperature and water content of DES on the extraction rate of corn cob xylan were investigated by the single factor test.Furthermore,the orthogonal test was designed to optimize the xylan extraction process.The structure of corn cob xylan was analyzed and verified.The results showed that the optimum extraction conditions of corn cob xylan were as follows:the ratio of corn cob to DES was 1:15(g:mL),the extraction time was 3 h,the extraction temperature was 60℃,and the water content of DES was 70%.Under these conditions,the extraction rate of xylan was 16.46%.The extracted corn cob xylan was distinctive triple helix of polysaccharide,which was similar to the structure of commercially available xylan.Xylan was effectively and workably extracted from corn cob by the DES method.This study provided a new approach for high value conversion of corn cob and the clean production of xylan.

Preparation and Characterisation of Corncob-Based Biosorbents in Côte d’Ivoire

This study focuses on the preparation of corncob-based biosorbents. The chemical impregnation method was used to vary the chemical agent namely phosphoric acid H3PO4 (BA) and sodium hydroxide NaOH (BB). The physicochemical analysis of the two biosorbents indicated that under the same preparation conditions, the bio-sorbents have after activation yields lower than 50% (24.37% for BB and 49.09% for BA). In addition, the biosorbents have iodine index values between 444.17 mg/g and 418.79 mg/g and specific surfaces related to the adsorption of methylene blue ranging from 18.54 m2/g to 19.70 m2/g. The study of surface functional groups by using the Boehm test and pH zero point charge (pHPZC) confirmed the acidic nature of BA and BB biosorbents with respective values pHPZC = 4.01 and pHPZC = 4.90. The Langmuir method and BET analysis determined the specific surface areas by liquid phase adsorption of methylene blue as well as the porosity. The BET surface areas of BA and BB obtained are 72.01 m2/g and 63.10 m2/g respectively. The influence of the chemical activating agent on the formation of pores was confirmed by electron microscopy (SEM) analysis. From this study, it is found that the best activating agent for corn cobs was found to be phosphoric acid because the BA biosorbent was revealed to be the most favourable due to its surface area and good pore volume which are high compared to sodium hydroxide NaOH. Moreover, their application as adsorbent for effluent treatment could be explored.

Facile preparation of N-doped corncob-derived carbon nanofiber efficiently encapsulating Fe2O3 nanocrystals towards high ORR electrocatalytic activity

Facile preparation of cost-effective and durable porous carbon-supported non-precious-metal/nitrogen electrocatalysts for oxygen reduction reaction(ORR)is extremely important for promoting the commercialized applications of such catalysts.In this work,the FeCl3-containing porphyrinato iron-based covalent porous polymer(FeCl3·FeP or-CPP)was fabricated in-situ onto porous corncob biomass supports via a simple one-pot method.Subsequent thermal-reduction pyrolysis at 700℃-900℃with CO2 gas as an activating agent resulted in Fe2O3-decorated and N-doped graphitic carbon composite Fe2O3@NC&bio-C with a high degree of graphitization of Fe-involved promotion during pyrolysis(Fe2O3=FeCl3·FePor-CPP derived Fe2O3;NC=N-doped graphene analog;bio-C=the corncob-derived hierarchically porous graphitic biomass carbon framework).The derivedα-Fe2O3 andγ-Fe2O3 nanocrystals(5-10 nm particle diameter)were all immobilized on the N-doped bio-C micro/nanofibers.Notably,the Fe2O3@NC&bio-C obtained at the pyrolysis temperature of 800℃(Fe2O3@NC&bio-C-800),exhibited unusual ORR catalytic efficiency via a 4-electron pathway with the onset and half-wave potentials of 0.96 V and 0.85 V vs.RHE,respectively.In addition,Fe2O3@NC&bio-C-800 also exhibited a high and stable limiting current density of-6.0 mA cm-2,remarkably stability(larger than 91%retention after 10000 s),and good methanol tolerance.The present work represents one of the best results for iron-based biomass material ORR catalysts reported to date.The high ORR activity is attributed to the uniformly distributedα-Fe2O3 andγ-Fe2O3 nanoparticles on the N-enriched carbon matrix with a large specific surface area of 772.6 m^2 g^-1.This facilitates favor faster electron movement and better adsorption of oxygen molecules on the surface of the catalyst.Nevertheless,comparative studies on the structure and ORR catalytic activity of Fe2O3@NC&bioC-800 with Fe2O3@bio-C-800 and NC&bio-C-800 clearly highlight the synergistic effect of the coexisting Fe2O3 nanocrystals,NC,and bio-C on the ORR performance.

Production of Ammonium Lactate by Fed-batch Fermentation of Rhizopus oryzaefrom Corncob Hydrolysate

L-(+)-Lactic acid production from corncob hydrolysate as a cheap carbohydrate source by fed-batch fermentation of Rhizopus oryzaeHZS6 was studied. After 96 h of fermentation in a 5 L fermentor, the final concentration of ammonium L-(+)-lactate, average productivity(based on initial xylose concentration) and maximum dry cell weight were 132.4 g/L, 1.38 g/(L·h), and 8.9 g/L respectively. The optical purity of L-(+)-lactate was 98.8%.

Brewing of low-alcoholic drink from corncobs via yeast-cellulase synchronous fermentation process

The present work focuses on the influence of various parameters, i.e., the dosage of cellulase, the inoculum concentration of yeast, the fermentation temperature and the fermentation time, on the alcohol content and sensory evaluation of the low-alcoholic health drink produced from corncob in a yeast-cellulase synchronous fermentation process. The fermentation was performed by inoculating the seed solution (containing corncob powder and yeast) and cellulase into the synchronous saccharification fermentation medium. Single-factor experiments and orthogonal experiments were performed, and the optimal processing conditions were obtained based on the characterizations of alcohol content and sensory evaluation. The results show that the alcohol content and sensory evaluation of the drink can reach 6.1 vol.% and 92, respectively, when the dosage of cellulase, inoculum concentration of yeast, the fermentation temperature and the fermentation time are 15 U/g, 7%, 32℃ and 84 h, respectively.

STUDY ON COMPONENTS OF FURFURAL RESIDUE FROM CORNCOB

In this paper, the components of furfural residue are analyzed. Total sugar content occupies 47.36% of absolute drying residue, and glucose occupies 83.23% of total sugar content. By combining the phcnyl nucleus exchange reaction with nitrobenzene oxidation, the quantity of structural units of phcnyl nuclei was determined, products from syringyl units occupy 50% of klason lignin. Especially, diphcnyl methane type syringyl units occupy 38.80%, and guaiacyl units 25%, other condensed guaiacyl units about 20%. The furfural residue is not a good material for the manufacture of adhcsivcs, but for active carbon. The yield of furfural residue may achieve about 350 thousand tons per year, but it has not been used in industry in China.

Effects of thermal activation conditions on the microstructure regulation of corncob-derived activated carbon for hydrogen storage

Activated carbons derived from corncob （CACs） were prepared by pyrolysis carbonization and KOH activation. Through modifying activation conditions, samples with large pore volume and ultrahigh BET specific surface area could be obtained. The sample achieved the highest hydrogen uptake capacity of 5.80 wt% at 40 bar and -196℃ The as-obtained samples were characterized by N2-sorption, transmission electron microscopy （TEM） and scanning electron microscopy （SEM）. Besides, thermogravimetric analysis was also employed to investigate the activation behavior of CACs. Detailed investigation on the activation parameters reveals that moderate activation temperature and heating rate are favorable for preparing CACs with high surface area, large pore volume and optimal pore size distribution. Meanwhile, the micropore volume between 0.65 nm and 0.85 nm along with BET surface area and total pore volume has great effects on hydrogen uptake capacities. The present results indicate that CACs are the most promising materials for hydrogen storage application.

Experimental investigation of performance properties and agglomeration behavior of fly ash from gasification of corncobs

The gasification industries make use of biomass residue as feedstock to produce synthesis gas,but the gasification of this waste biomass generates tons of ash everyday.Performance properties and agglomeration behavior of corncob ash(CCA) collected from the gasification of corncobs in a pilot-scale gasification station were investigated by using some experimental methods.Based on the chemical composition results,the agglomeration tendency of CCA from combustion and gasification process was also analyzed.Chemical analysis shows that the fly ash is mainly composed of inorganic matters formed by K,Mg,Ca,Na,Fe,Al,S,etc.The agglomeration characteristics indicate that the slagging degree increases with the increase of ashing temperature,and the slagging tendency of these CCA samples from gasification or combustion is different with various slagging indices.All CCA samples from combustion or gasification can cause slagging/fouling problems in thermal conversion systems.The applications of CCA are closely related to its performances,and CCA has the potential to be used in various fields,for example,as a material for ceramic products and activated carbon,as an adsorbent,as a crude fertilizer,and as a structural material.

Study on the Impact Factors of COD Throughput in Corncob Extract

[ Objectivel The study aims to discuss the impact factors of COD （chemical oxygen demand） throughput in corncob extract. [ Method ] Firstly, as the variations of the mass concentration of corncob, temperature, time and pH, the throughput of COD in corncob extract were analyzed respectively. Afterwards, through the orthogonal test, the best conditions for extracting organic matter from corncob were determined. [ Result] The single-factor tests showed that there was a linear relationship between the mass concentration of corncob and COD of corncob extract when the mass concentration of the corncob was lower than 50 g/L; COD of corncob extract was higher under acidic or alkaline conditions. The optimum con- ditions for extracting organic compounds from corncob were as follows： temperature was 35 ℃, mass concentration was 40 g/L, pH =3, and ex- tracting time was 3 hours; under this conditions, the mass of COD released from a unit mass of corncob reached 0.056 2 g. [ Conclusien] The re- search could decrease the treatment cost of wastewater from uranium mining in mines and make corncob more useful.

Studies on Removal of Ammonia Nitrogen From Wastewater Using Modified Corncob

Water pollution caused by ammonia nitrogen is of major concern in many parts of the world due to the danger it poses to the environment and human health.This study focuses on the development of an inexpensive and environmental adsorbent by means of modified corncob.The objective of this paper was to investigate the adsorption behavior of NH^+_4-N from wastewater by modified corncob.Corncob was modified with KMn O_4.The physico-chemical properties of modified corncob were characterized by fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM).It was found that the adsorption capacity of corncob was improved significantly after modification with KMn O_4.The p H significantly affected the adsorption efficiency of modified corncob to NH^+_4-N.The best p H value of corncob adsorbing NH^+_4-N was 7.The coexistence of Na^+had a significant effect on the adsorption of NH^+_4-N.The adsorption process of modified corncob to NH^+_4-N followed the pseudo-first order kinetic model.Langmuir model could well simulate the adsorption behavior of NH^+_4-N on modified corncob.The maximum adsorption capacity of NH^+_4-N on modified corncob can reach 4.85 mg/g.The adsorption process of NH^+_4-N was monolayer adsorption.Moreover,modified corncob adsorbed NH^+_4-N was fertilizer conservation especially for nitrogen.The utilization of modified corncob with NH^+_4-N adsorption in the farmland could promote the gradual release of nutrients,thus providing nutrients for plant growth.It was proposed that if combined with biological method,the amount of removed NH^+_4-N from wastewater could be increased significantly.

Feasibility of Using Corncob as the Substrate for Natural Vinegar Fermentation with Physicochemical Changes during the Acetification Process

Vinegar made from corncob, an agricultural waste product of corn, is of interest in terms of its potential as a new functional condiment with physiological characteristics derived from polyphenols. The advent of food out of waste using lignocellulosic substrates is a modern biotechnological approach to enhance sustainability. The fermentation parameters for production of fermented vinegar from corncobs were optimized. The ethanolic fermentation was completed by Saccharomyces cerevisiae in 52 hours at 36℃ producing 3.16% (v/v) ethanol. The acetic acid fermentation was carried out by Acetobacter aceti in 48 hours at 34℃for producing vinegar having 3.91% (w/v) acetic acid. Total phenolic compound of corncob wine and vinegar was reported as 49 mg/100ml and 43 mg/100ml respectively. Total flavonoid content was determined to be about 12 mg/100ml of corncob wine and 9 mg/100ml of corncob vinegar. Corncob wine and vinegar showed highest antioxidant activity with 39% and 37.94% respectively. The structural change during the two step fermentation was also confirmed by scanning electron microscope (SEM). The Hunter color value of the corn cob vinegar was also evaluated. With the current trend of shifting to natural products, corncob vinegar with better health benefits and economic significance, certainly scores high above its synthetic counterpart.

Transient and Steady State Currents of Bisphenol A Corncobs Sample

Transient current (I-t), current-voltage (I-V) characteristics, and dc conductivity ln(σ) for bisphenol A corn-cobs (BPACC) sample were investigated. At higher temperatures, I-V characteristics reveal that the dc cur-rent for the sample undergoes two regions one due to ohmic conduction and the other has been attributed to Space charge limited current (SCLC). The activation energy (Ea), the electron mobility μo), effective electron mobility ?μe), the concentration of the charge’s concentrations in conduction band, trapping factor (θ) and the trap concentration (Nt) were calculated. At lower temperatures, the dc current exhibits a peculiar behavior for I-t regime and I-V characteristics. Transient current of BPACC sample exhibits approximately constant value at constant electric field and it has saturation value for I-V characteristics. The attained results suggest strongly the applicability of this material in the electrical applications.

Production of Citric Acid from Corncobs with Its Biological Evaluation

Corncobs could serve as a substrate for citric acid production using solid state fermentation technique. The culture optimization concerning substrate concentration, culture duration, pH, temperature and substrate hydrolysis was carried out for maximum productivity of citric acid. Under the optimized conditions, 48.4 g of citric acid was produced from 1 kg dry corncobs. Biological evaluation was carried out for citric acid such as melanin synthesis inhibitory, anti-allergy, anti-bacterial, and hyaluronic acid production activities. The results showed that citric acid has potent melanin inhibitory activity, good inhibition for β-hexosaminidase release and potent stimulatory effect for the production of hyaluronic acid. These activities (melanin synthesis inhibitory, anti-allergy and hyaluronic acid productive activities) of citric acid have been reported for the first time.

Lignin-containing Microfibrillated Cellulose Prepared from Corncob Residue via Calcium Hydroxide Co-grinding and Its Application in Paper Reinforcement

In this study,lignin-containing microfibrillated cellulose(MFC)was prepared from corncob residue after xylose extraction via co-grinding with calcium hydroxide.The product was then compared with the MFC obtained by direct grinding and applied to strengthen paper.The chemical composition and morphological structure analysis results showed that the corncob residue can be used to prepare lignin-containing MFC and does not require further purification.Moreover,the co-grinding with calcium hydroxide is easier to fibrillate corncob residue.The MFC obtained by cogrinding with calcium hydroxide had a higher aspect ratio,and its surface was coated with calcium carbonate nanoparticles.MFCs obtained by both the methods mentioned above had an obvious strengthening effect on paper.Compared with the paper without MFC,the tensile index,elongation,burst index,and folding strength of the paper with MFC obtained by co-grinding with calcium hydroxide significantly increased by 17.5%,22.1%,19.5%,and 157.1%,respectively.This study provides a novel idea for the utilization of corncob residue,which may enhance the value and promote the comprehensive utilization of corn by-products.

SnO_2/corncob-derived activated carbon nanohybrid as an anode material for lithium-ion batteries

A facile synthesis of Sn O2/corncob-derived activated carbon（CAC） composite was proposed,and the CAC used here has high specific surface area（over 3000 m2/g） and ample oxygen-containing functional groups.The microstructures and morphology as well as electrochemical performance of the Sn O2/CAC composites were investigated by X-ray diffraction,scanning electron microscopy,transmission electron microscopy and relevant electrochemical characterization. The results show that the mass ratios of Sn O2 to CAC have a significant effect on the structures and properties of the composites. The sample with 34% Sn O2 delivered a capacity of 879.8 m Ah/g in the first reversible cycle and maintained at 634.0 m Ah/g（72.1% retention of the initial reversible capacity） after 100 cycles at a current density of 200 m A/g. After 60 cycles at different specific currents from 200 to 2000 m A/g,the reversible specific capacity was still maintained at 632.8 m Ah/g at a current density of 200 m A/g. These results indicate that SnO 2/CAC can be a desirable alternative anode material for lithium ion batteries.

Growth Performance, Carcass Quality, Visceral Organs and Intestinal Histology in Broilers Fed Dietary Dried Fermented Ginger and/or Fermented Corncob Powder

To determine whether dried fermented ginger (DFG), fermented with Japanese mugwort silage juice, could be replaced by fermented corncob powder (FCP) as a of feed ingredient source without significant body weight decrease or damage to visceral organs (using gross anatomical observation), to intestinal villi (using light microscopy), or to the epithelial cells on the villus apical surface (using scanning electron microscopy) the following investigation was performed. Sixty-four male broilers were allotted to 4 groups: a basal diet group (control group), and basal diet groups with DFG at a level of 50 ppm;with DFG at 50 ppm and FCP at 250 ppm (50 ppm DFG + 250 ppm FCP group);and with FCP at a level of 500 ppm (500 ppm FCP group). Feed intake, body weight gain, feed efficiency, carcass quality, small intestinal length and weight, and visceral organ weight were not different among groups. Furthermore, regarding intestinal villus height, villus area and crypt depth, a significant difference was not found among the groups. When these values of the control were expressed as an index of 100, the duodenal villus height of the 50 ppm DFG + 250 ppm FCP group and the 500 ppm FCP group were 114 and 119, respectively. The duodenal villus area of the 50 ppm DFG + 250 ppm FCP group and the 500 ppm FCP group were 125 and 158, respectively. These villus heights and areas are thought to be activated. On the epithelial cells on the villus apical surface in the duodenum and jejunum, the 50 ppm DFG + 250 ppm FCP group had protuberated cells into the intestinal lumen and deeper cells at the sites of recently exfoliated cells, suggesting that these cells are activated. The present results indicate that small amounts of fermented corncob powder can be used as a feed supplement when mixed with fermented ginger powder, due to the synergy between the two ingredients, resulting in a 6% increase in body weight gain。

Synthesis and flocculation characteristics of cationic modified corncob: A novel polymeric flocculant

A novel organic polymeric flocculant was synthesized by grafting cationic etherifying monomer (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride (CHPTAC) onto the backbone of corncob powder (CP,F≤ 30mm). The synthetic reaction between CP and CHPTAC was initiated by hydroxyl radical made from Fenton reagent(H2O2-FeSO4). The alkalization process andsynthetic reaction conditions were optimized byva- rying several parameters affecting grafting efficiency, such as NaOH dose, monomer concentration, reaction temperature and time and distilled water dose. The synthesized cationicflocculant was characterized by elemental analysis,Fourier-transform infrared spectrometer andscanning electron microscope techniques. Itwas concluded that the backbone of CP have been grafted cationic etherifying monomer. The flocculation characteristics in 0.25% (w/v) kaolin suspensions was compared with some of thecommercial flocculants available in markets,and the results demonstrated the synthesized cationic flocculation has superiority as a novel flocculant.

Comparison of Physical Properties and Microbial Indexes of Five Kinds of Commercial Corncob Beddings

[Objectives]This study was conducted to select suitable mouse beddings from commercial corncob bedding(A-E)produced by five different manufacturers.[Methods]The physical properties and microbial indexes of the five kinds of corncob bedding were studied by means of visual inspection,dust content determination,moisture content determination,water absorption tests and microbial detection.[Results]In visual inspection,corncob bedding A was better than other four kinds.During dust content determination,corncob bedding D was higher than other 4 kinds(1.83%±0.2983%,P<0.05).In terms of moisture content,the moisture contents of the five kinds of corncob bedding were less than or equal to 10%.In the water absorption test,the water absorption capacities of the five kinds of bedding before autoclaving were all greater than 150%,and the water absorption of corncob bedding D after autoclaving was better than other four kinds(171.0±5.3,P<0.05).During microbial detection,the total number of colonies of corncob bedding B before autoclaving was higher than those of other four types(1.42×10^(5)±4.3×10^(4),P<0.05).The five kinds of commercial corncob bedding have different physical parameters and microbial conditions,and each has its own advantages and disadvantages.When purchasing and selecting corncob bedding,it is necessary to comprehensively consider the needs of daily feeding work,and choose bedding according to the effects on the health and welfare of experimental animals.[Conclusions]This study provides a reference for selecting suitable corncob bedding for mouse.

Experimental,Thermodynamic and Kinetic Studies for the Adsorption of Phenolic Compounds Derived from Oilfield Wastewater by the Corncob Hydrochar

The corncob hydrochar is prepared by using a stainless autoclave at 230?C for 8 h.The products are characterized by elemental analyzer,Fourier Transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and scanning electron microscope(SEM).The effects of hydrochar dosage,pH,adsorption time and phenol concentration on the adsorption performance of hydrochar are investigated by means of single-factor experimental analysis.Based on the experiments the adsorption thermodynamic and kinetics are tentatively discussed.The results show that abundant oxygen-containing functional groups are scattered on the surface of the corncob hydrochar.The adsorption kinetics of phenol on the hydrochar corresponds well with pseudo-second-order kinetic model.Thermodynamic studies indicate that Freundlich adsorption isotherm model is much better than Langmuir model in describing the adsorption of phenol on the corncob hydrochar at 25?C-45?C.This study provides scientific basis for the development of cheap and efficient adsorbents for the removal of phenols derived from oilfield wastewater.

Effects of cultivation conditions on the optical purity of L(+)-lactic acid produced from corncob hydrolysate by Rhizopus oryzae

The effect ofcultivation conditionson the opticalpurity ofL(+)-lactic acid produced by Rhizopusoryzae HZS6 from corncob hydrolysate was investigated. The isomeric composition of lactic acid was influenced by the supplementation of L(+)-lactic acid to fermentation medium. L(+)-Isomer increased with the dosage,no(-)-lactic acid was observed when the concentration of supplemented L(+)-lactic acid in matrix was≥1.5g l-1. However,the L(+)-lactic acid yield decreased with the dosage. Under suitable conditions,100g l-1 initial corncob xylose,2g l-1 NH4NO3,1.5 g l-1 supplemented L(+)-lactic acid,R. oryzae HZS6 could produce 100% L(+)-form lactic acid with the yield of 75% and final concentration of 81.2 g l-1,at pH 6.0 and temperature 34℃.