Table of Content

25 February 2021, Volume 41 Issue 1 Previous Issue    Next Issue

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Determination of Deprotonation Characteristics of Tannic Acid by Potential Titration Method Liangliang ZHANG, He ZHANG, Man XU, Xinyu HU, Yiwen LIU 2021, 41 (1):  1-6.  doi: 10.3969/j.issn.0253-2417.2021.01.001 Abstract ( 696 )   HTML ( 1100269915 )   PDF (2389KB) ( 671 )   Save The deprotonation process of a typical tannic acid, 1, 2, 3, 4, 6-penta-O-galloyl-β-D-glucopyranose(PGG), and its parent compound methyl gallate(MeG) was studied by pH potentiometric titration and spectrophotography. The dissociation constants of PGG and MeG were calculated by chemometric methods using the Reactlab Equilibrium software. Concentration profiles of the fully protonated PGG and its two deprotonated forms at different pH values were also predicted by the chemometric method. The results showed that the deprotonation of phenolic hydroxyl of PGG was found with the increasing of pH value, and fully deprotonated forms of PGG existed at pH>11. These formed negative ions of oxygen can further coordinate with metal ions. Spectroscopic studies showed that there were two deprotonated forms of PGG, and the corresponding pKa values were 10.84±0.03 and 10.62±0.02. There was only one deprotonated form of MeG during titration, and the corresponding pKa value was 9.68±0.02. Figures and Tables | References | Related Articles | Metrics

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Preparation and Properties of Maleopimaric-based Epoxy Nanocomposite Pan TAO, Chengyu WU, Shiying MAO, Meixin WANG, Jian LI 2021, 41 (1):  7-14.  doi: 10.3969/j.issn.0253-2417.2021.01.002 Abstract ( 371 )   HTML ( 2442566 )   PDF (2511KB) ( 636 )   Save Maleopimaric anhydride(MPA) was prepared from rosin by Diels-Alder addition, and then maleopimaric epoxy resin(MPA-ER) was prepared by esterification and closed-loop reaction. The structures of MPA and MPA-ER were characterized by FT-IR and 1H NMR.A series of MPA-ER/MWCNTs composites were prepared by blending multi-wall carbon nanotubes(MWCNTs) with MPA-ER, the mechanical and thermal properties of the composites were characterized, and the effects of MWCNTs addition on the mechanical and thermal properties of maleopimaric epoxy nanocomposites were investigated. The results of FT-IR and 1H NMR showed that MPA and MPA-ER were successfully prepared. MWCNTs were well dispersed in MPA-ER, and the cross-section had river-shaped texture features. The mechanical properties of MPA-ER/MWCNTs were significantly improved by adding MWCNTs. When the addition of MWCNTs was 1.2%(calculated by the mass of MPA-ER, similarly hereinafter), the mechanical properties of the composite MPA-ER/MWCNTs(1.2) were optimized. Its impact toughness, tensile strength, bending strength and elongation at break were 15.11 kJ/m2, 40.42 MPa, 105.45 MPa and 14.80%, which increased by 159%, 160%, 102% and 135% compared with those of MPA-ER, respectively.At the same time, in cone calorimeter test, the peak heat release rate and carbon residue rate of MPA-ER/MWCNTs(1.2) composite were 324 kW/m2 and 9.18%, respectively.Compared with MPA-ER, the peak heat release rate decreased by 14%, and the carbon residue rate increased by 68%, which indicated that the addition of MWCNTs also improved the thermal stability and flame retardancy of MPA-ER/MWCNTs.The improvement of flame retardancy of MPA-ER/MWCNTs(1.2) composites was mainly attributed to the effective increase of crosslinking density of epoxy resin by adding MWCNTs, and forming a relatively dense carbon layer in the interior of epoxy resin, and then the flame retardant effect was achieved by partially isolating the external heat and air. Figures and Tables | References | Related Articles | Metrics

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Synthesis of 2, 3, 4, 4'-Tetrahydroxybenzophenone from 1, 2, 3-Trimethoxybenzene Lanxiang LIU, Weidong HUANG, Gang DONG, Kun LI, Jinju MA, Hong ZHANG 2021, 41 (1):  15-20.  doi: 10.3969/j.issn.0253-2417.2021.01.003 Abstract ( 357 )   HTML ( 6662 )   PDF (546KB) ( 496 )   Save To prevent the oxidation of raw materials(pyrogallic acid and p-hydroxybenzoic acid)during the traditional synthesis of 2, 3, 4, 4'-tetrahydroxybenzophenone(4HBP), an intermediate compound, 2, 3, 4, 4'-tetramethoxydibenzone(4TMP), was synthesized for the first time by the hydroxyl protection method. 1, 2, 3-trimethoxybenzene(TMB) and p-anisic acid(p-AA) were used as the raw materials, and Eaton reagent and 1, 2-dichloroethane were used as the catalyst and solvent, respectively. The target product, 2, 3, 4, 4'-tetrahydroxybenzophenone, was synthesized by demethylation of the intermediate in a BBr3/CH2Cl2 system with anhydrous, anaerobic and low temperature conditions. The yield of the target product was approximately 86.4%, and the purity was ≥98.8%, the content of each metal ion was less than 18.60 mg/kg.The structures of the intermediate and target products were investigated by IR, NMR, and MS. Figures and Tables | References | Related Articles | Metrics

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Preparation and Characterization of Turpentine-based Polyamide Flame Retardant Material Fuhao DONG, Xincheng ZHOU, Penghao SUN, Lizhen GUO, Xu XU, Shifa WANG 2021, 41 (1):  21-28.  doi: 10.3969/j.issn.0253-2417.2021.01.004 Abstract ( 304 )   HTML ( 24624 )   PDF (2441KB) ( 555 )   Save By using camphene, a derivative of turpentine, as a raw material; a flame-retardant monomer, N-trimethoxysilylpropyl-N-isobornylacrylamide (NPSBAM); and N-isopropylacrylamide (NIPAM), a flame-retardant copolymer—P(NIPAM-co-NPSBAM)—was prepared through the random copolymerization of NPSBAM and NIPAM. The structure, morphology, mechanical properties, and flame retardancy of the copolymer were analyzed. The results showed that the vibration peak of Si—O—C was found in the infrared spectrum, and the carbon-carbon double bond basically disappeared, which indicated that the turpentine silicone monomer NPSBAM was successfully introduced into the copolymer P(NIPAM-co-NPSBAM). Scanning electron microscopy revealed that the surface of NPSBAM-2 was rough, because of the introduction of the rigid ring.Moreover, as the content of NPSBAM increased, the water contact angle increased, indicating that the hydrophobicityof polyamide materialincreased. In addition, thermogravimetric analysis suggested that the introduction of the organosilicon monomer promoted carbon formation in the polyamide materials, and the amount of the residue increased with increasing organosilicon content. The analysis of the thermal decomposition kinetics indicated that with an increase in the content of the flame-retardant monomer, NPSBAM, the average activation energy increased from 123 to 166 kJ/mol. This indicated that the thermal stability of polyamide increased with an increase in the NPSBAM content. The mechanical property test showed that the tensile strength of polyamide increased from 5.2 to 7.2 MPa, which proved that the presence of the rigid ring in the turpentine monomer caused an improvement of the mechanical properties of polyamide. Furthermore, flame retardancy tests showed that the flame retardancy of the polyamide materials was improved.The limiting oxygen index(LOI)also increased from 16.4% to 23.9%. Figures and Tables | References | Related Articles | Metrics

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Effect of Post-harvest Treatment on the Product Quality of Chinese Gallnut Wenwen ZHANG, Kun LI, Baoshan TANG, Pinde ZHANG, Yiwen LIU, Hong ZHANG 2021, 41 (1):  29-37.  doi: 10.3969/j.issn.0253-2417.2021.01.005 Abstract ( 355 )   HTML ( 6405 )   PDF (793KB) ( 531 )   Save The effects of two pretreatments, steam blanching(SB) and boiling water blanching(BWB), on fresh Chinese gallnuts were studied. After the pretreatment, oven drying(OD), fluidized bed drying(FBD), natural drying(ND), and ultraviolet irradiation(UVI) were selected to dry gallnuts and the effects of the four drying methods on the quality of the gallnut products were investigated.The results showed that: after two pretreatments, the moisture content and tannic acid content of the gallnut products decreased, especially after steam blanching, which resulted in a decrease in the moisture content to 47.68%, which was significantly different from that of untreated gallnut(55.77%). Heat treatment reduced the tannic acid content, while the gallic acid content in the dried gallnuts increased. The tannic acid content of ND gallnut was 50.12%-56.84%, and the gallic acid content was 0.29%-0.46%. After oven drying, the tannic acid content in the gallnuts decreased to 32.48%-42.43%, while the gallic acid content was as high as 2.97%-4.39%; different post-harvest treatments had different effects on the quality of the products. Boiling water blanching or steam blanching combined with ultraviolet irradiation could increase the drying rate of gallnuts and had little effect on the tannin content of the products. Oven drying and fluidized bed drying could reduce the drying time to less than 5 h, but the tannic acid content(32%-43%) in the obtained gallnut products was also reduced significantly; ND after pretreatment could maintain the original structure of tannin, but the drying time was more than 200 h.Therefore, the post-harvest treatment of fresh gallnut could be selected according to the actual operating conditions and its applications. Industries should pay more attention to drying efficiency when choosing the treatments of gallnuts; a combination of steam blanching and fluidized bed drying is more preferred. Figures and Tables | References | Related Articles | Metrics

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Oil Cell Morphology, Essential Oil Constituents and Antioxidant Activity of Cinnamomum longepaniculatum Leaves Harvested in Spring and Autumn Xian CHENG, Liangwu BI, Shengnan LI, Yuxiang CHEN, Zhendong ZHAO, Kailin MO 2021, 41 (1):  38-44.  doi: 10.3969/j.issn.0253-2417.2021.01.006 Abstract ( 539 )   HTML ( 299056 )   PDF (7074KB) ( 549 )   Save The tissue transparency method was used to observe the morphology of oil cells in the leaves of Cinnamomum longepaniculatum(Gamble) N. Chao ex H. W. Li in spring and autumn, and the density and diameter of the oil cells were determined. Cell wall structure of the oil cells was observed with scanning electron microscopy. GC-MS was used to characterize the chemical composition of the essential oils extracted from the leaves of C. longepaniculatumin in spring and autumn.Eucalyptol, α-terpineol, and γ-terpinene content was analyzed by GC. Finally, antioxidant activity of the essential oils was evaluated. The density of oil cells of C. longepaniculatum leaves in spring and autumn was (41±3) and (38±2) per mm2, the diameter was (51.87±1.64) and (36.89±2.64) μm, and the cell wall thickness was 1.65 and 0.63 μm, respectively. The extraction yields of essential oils from C. longepaniculatum leaves were 4.45% and 3.09%(based on dry weight) in spring and autumn, respectively. Sixteen types of chemical compounds were identified with GC-MS, and no significant difference was observed in the content of the three main components. The total antioxidant capacity of the essential oils from C. longepaniculatum leaves harvested in spring and autumn was 6.50 and 5.50 U/mL, respectively (40% of Vc), and the IC50 value corresponding to scavenging of DPPH free radicals was 0.2 g/L. Figures and Tables | References | Related Articles | Metrics

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Preparation of Nanoemulsion of Lacquer Seed Oil and Its Anti-oxidation and Anti-UV Activity Hao ZHOU, Xingying XUE, Hongxia CHEN, Jianzhong YE, Chengzhang WANG 2021, 41 (1):  45-52.  doi: 10.3969/j.issn.0253-2417.2021.01.007 Abstract ( 397 )   HTML ( 7 )   PDF (1588KB) ( 486 )   Save Using lacquer seed oil as raw material, sodium caseinate as emulsifier, nanoemulsion of lacquer seed oil was prepared by high pressure homogenization, the optimum preparation conditions of nanoemulsion of lacquer seed oil were deter mined by single factor test; the storage stability of lacquer seed oil under different temperature was investigated; the antioxidant activity was evaluated; in vitro cellularmethod was used to investigate the anti-UV radiation activity of lacquer seed oil nanoemulsion. Results showed that the optimum preparation conditions of lacquer seed oil nanoemulsion were the mass fraction of emulsifier 2.5%, the mass fraction of lacquer seed oil 6%, homogeneous pressure 100 MPa, homogenization 4 times, the resulted nanoemulsion showed average particle size of 163.0 nm, Zeta potential of -41.01 mV, polydispersity index (PDI) of 0.225, and good storage stability, the average particle size could keep within 200 nm under storing for 30 d at 4, 25, 60 ℃. The median effective concentration (EC50) values of DPPH, ABTS and hydroxyl radicals were 24.26, 23.77 and 21.10 mg/L, which showed better antioxidant activity than positive control vitamin C(38.48, 43.25and 40.56 mg/L). Lacquer seed oil nanoemulsions had significant repair effects on NIH 3T3 cells with ultraviolet A (UVA) radiation damage, the survival rate of UVA damaged NIH 3T3 cells was higher than 100% when the mass concentration of nanoemulsion was more than 5 mg/L, which indicated that lacquer seed oil nanoemulsion had good anti-UV radiation activity. Figures and Tables | References | Related Articles | Metrics

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Extraction Process and Components Analysis of Oil from the Seeds of Euscaphis konishii Hayata Shuqin CHEN, Yanyan YE, Yingxuan QUAN, Linhai LI, Lin NI, Shuangquan ZOU 2021, 41 (1):  53-59.  doi: 10.3969/j.issn.0253-2417.2021.01.008 Abstract ( 345 )   HTML ( 227 )   PDF (998KB) ( 542 )   Save To high-efficiency use the seeds of Euscaphis konishii Hayata, n-hexane and heating reflux extraction was used to extract oil from the seeds of E. konishii, and the effects of extraction time, extraction temperature and liquid/solid ratio of n-hexane and E. konishii seed on extraction rate were investigated. Based on the results of single-factor test, Box-behnken response surface design and data analysis were carried out by using Design-Expert 8.0.6 software to further optimize the reflux extraction process of E. konishii seed oil. The results showed that the order of the factors affecting the extraction rate were extraction time, extraction temperature and liquid/solid ratio.The optimal extraction process was heating reflux extraction time 62.04 min, extraction temperature 80.2 ℃ and liquid/solid ratio 10.14:1(mL: g). The predicted extraction rate under these conditions was 5.84% and the total extraction rate obtained from verifying test was (5.85±0.001)%, which was close to the predicted value and the relative error was 0.17%, indicating that the response surfaced optimized extraction process of E. konishii seed oil was stable and workable. Meanwhile, by analyzing the oil extracted from seed of E. konishii, the yield of kernel oil was (35.6±0.7)% and the yield of seed coat oil was (2.1±0.15)%, 18 fatty acid components were defected, among which the unsaturated fatty acids were 65.52%, and linoleic acid content was up to 45.64%. Figures and Tables | References | Related Articles | Metrics

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Aromatic Chemicals Produced by Hydrogenolysis of Lignin Extracted from Phyllostachys heterocycla Hydrolysis Residues Yi CHENG, Yixin QU, Sheng YANG, Kang ZHUANG, Jidong WANG 2021, 41 (1):  60-66.  doi: 10.3969/j.issn.0253-2417.2021.01.009 Abstract ( 429 )   HTML ( 1638849 )   PDF (509KB) ( 557 )   Save Two kinds of lignin were extracted from moso bamboo(Phyllostachys heterocycla) hydrolysis residue by hydrogen peroxide method and methanol method. The process of catalytic reductive hydrogenolysis was investigated. The results of two kinds of lignin conversion and product distribution were compared at the same reaction temperature and reaction time. Meanwhile, the optimal conditions of hydrogen peroxide lignin conversion were optimized. When the reaction temperature was 220 ℃, the reaction time was 60 min, lignin extracted by hydrogen peroxide could be converted entirely into soluble substance, and the monomer yield was 14.85%. The soluble substance yield of lignin extracted by methanol method was 96.8%, the monomer yield was 7.13%. The results showed that the conversion efficiency of hydrogen peroxide lignin to aromatic chemicals was higher than that of methanol lignin at reductive hydrogenolysis. The reductive hydrogenolysis process restored the benzoquinone of hydrogen peroxide lignin to the aromatic structure. The side chains in the product were mainly carbonyl, carboxyl, aldehyde, and alkane groups. Figures and Tables | References | Related Articles | Metrics

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Preparation Conditions and Properties of O/W Type Litsea cubeba Oil Microemulsion Chen CHENG, Hongyan SI, Zongde WANG, Shengliang LIAO, Chenyang ZOU, Peng WANG 2021, 41 (1):  67-76.  doi: 10.3969/j.issn.0253-2417.2021.01.010 Abstract ( 479 )   HTML ( 13895 )   PDF (2016KB) ( 546 )   Save A microemulsion of Litsea cubeba(Lour.) Pers. oil was prepared by adding water. The influence of different surfactant and cosurfactant-types, the mass ratio of surfactant to cosurfactant(Km), and preparation temperature on the formation of water-in-oil(O/W) type microemulsion of L. cubeba oil were investigated using a single factor method, and through orthogonal experiments, the optimum preparation process of O/W type L. cubeba oil microemulsion was determined as follows: Triton X-100 as surfactant, absolute alcohol as cosurfactant, Kmvalue was equal to 1, and preparation temperature was set to 25 ℃. Under the best preparation conditions, the ratio of the mixed surfactant and the essential oil of L. cubeba was 9∶1, and the water content was 70% for sample 1. The average particle diameter, polydispersion coefficient, conductivity and pH value of sample 1 were 13.43 nm, 0.125, 83 mS/m, and 5.82, respectively. The performance test and analysis of sample 1 showed that there was no change in the appearance of the microemulsion when it was centrifuged at the rate of 1 000 to 4 000 r/min, which could prove that the centrifugal stability was better than essential oil. Adding the same amount of methylene blue aqueous solution to sample 1 and essential oil, its diffusion rate in sample 1 was significantly faster than that in the essential oil, which proved that the water solubility of microemulsion was significantly better than that of the essential oil.After 12 h of sustained-release, the content of sustained-release citral in the microemulsion was significantly less than that of the sustained-release citral in the essential oil, indicating that the sustained release of the microemulsion was better than that of the essential oil itself. The results of 1, 1-diphenyl-2-picrylhydrazyl free radical(DPPH·) and 2, 2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) radical(·ABTS+) scavenging experiments indicated that DPPH· and·ABTS+ scavenging rates of sample 1 of L. cubeba essential oil microemulsion were significantly higher than those of essential oil in the concentration range of 10-30 g/L. The DPPH·and·ABTS+ scavenging rates of the L. cubeba essential oil microemulsion sample 1 at 30 g/L concentration were 95% and 54.7%, while those of L. cubeba essential oil were only 44.79% and 16.4%, respectively, indicating that L. cubeba essential oil prepared as microemulsion could significantly improve its antioxidant property, and the anti-oxidation property of microemulsion to DPPH· was significantly better than that of·ABTS+. Figures and Tables | References | Related Articles | Metrics

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Preparation of Xylooligosaccharides and Monosaccharides from Bamboo Chips by Liquid Hot Water Pretreatment Yunni ZHAN, Chen HUANG, Xin HAO, Zimeng WANG, Yongjun DENG, Guigan FANG 2021, 41 (1):  77-84.  doi: 10.3969/j.issn.0253-2417.2021.01.011 Abstract ( 498 )   HTML ( 37760001 )   PDF (1565KB) ( 695 )   Save Effects of liquid hot water pretreatment(LHWP) on the chemical composition, enzymatic digestibility, and xylooligosaccharides(XOS)concentration were investigated in Bambusa emeiensis. In addition, the physical and chemical structural variationsof thesamples before and after the pretreatment were studied using a X-ray diffraction(XRD)spectrometer and Fourier transform infrared spectroscopy(FT-IR). Results indicated that the xylan content was significantly decreased after LHWP, while the contents of glucan and lignin increasing accordingly. LHWP improved the enzymatic digestibility of the bamboo chips feedstock, and the enzymatic hydrolysis yield reached the maximum of 79.0%(glucan) and 92.0%(xylan) at a pretreatment intensity coefficiency of 4.50. However, the XOS concentration reached the maximum value(8.7 g/L)at an intensity coefficiency of 3.96(relative mass percentage of 55.3%), and decreased thereafter as the pretreatment strength was further increased. Finally only 0.5 g/L(relative mass percentage of 3.1%)XOS was obtained in the pretreatment prehydrolysate at an intensity coefficiency of 4.50. Figures and Tables | References | Related Articles | Metrics

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Catalytic Upgrading of Cellulose Pyrolysis Vapor for Furan Compounds Keming ZHU, Dechao WANG, Yongfeng ZHU, Wenbin LI, Yunwu ZHENG, Zhifeng ZHENG 2021, 41 (1):  85-92.  doi: 10.3969/j.issn.0253-2417.2021.01.012 Abstract ( 355 )   HTML ( 747 )   PDF (2206KB) ( 546 )   Save Two catalysts—MnCo2O4 and manganese oxide octahedral molecular sieves(OMS-2) were synthesized using co-precipitation and hydrothermal methods, respectively. On comparing these with the NaY molecular sieve for the catalytic pyrolysis of cellulose, the NaY molecular sieve was further modified to improve its catalytic activity. Co/NaY, Sn/NaY, and Co-Sn/NaY were prepared using the impregnation method.Catalytic upgrading of cellulose pyrolysis vapors for the preparation of furan compounds with different catalysts were investigated. The prepared catalysts were characterized through nitrogen adsorption-desorption, X-ray diffraction(XRD), scanning electron microscopy(SEM), and ammonia adsorption-desorption(NH3-TPD) methods. Experimental results showed that Co or Sn metal was dispersed on the NaY surface keeping the crystal structure and morphology of NaY intact. However, the specific surface area and pore volume of the catalyst decreased after metal loading, while average pore size increased. The acidic sites of the NaY zeolite remained virtually unchanged after Sn loading, but decreased after Co loading. The specific surface area of NaY and modified NaY were much larger than those of MnCo2O4 and OMS-2 but the average pore size was smaller. Addition of catalysts promoted the production of alcohols, acids, and aldehydes but inhibited sugar production. The furan content increased significantly from 15.34%(non-catalytic pyrolysis) to 48.16% and 61.88% on using NaY alone and Co/NaY, respectively, albeit the mass ratio of cellulose to catalyst was 1:14. Both the Co and Sn metals-supported NaY catalysts promoted furanone production but inhibited furan production. Figures and Tables | References | Related Articles | Metrics

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Degradation of Single Simulant of Resin in Paper Pulp Usinga Laccase/Mediator System Faxing QIN, Tingting MENG, Lefan MA, Xutao ZHANG, Hongbing LI 2021, 41 (1):  93-99.  doi: 10.3969/j.issn.0253-2417.2021.01.013 Abstract ( 325 )   HTML ( 8 )   PDF (645KB) ( 379 )   Save The laccase produced by Phanerochaete chrysosporium was used to degrade the resin simulants rosin acid, linoleic acid, oleic acid, β-sitosterol, and sterol oleate. By comparing the degradation efficiency of the laccase/mediator system, the most suitable mediator for the laccase was selected. The effects of this system on the degradation of simulants were investigated, and the degradation kinetics of linoleic acid and oleic acid were studied. The technological process conditions for linoleic acid degradation via utilization of laccase were optimized. The results showed that 1-hydroxybenzotriazole(HBT) was a suitable mediator. The laccase/HBT system exerted a better degradation effect on the simulants rosin acid, linoleic acid, oleic acid, β-sitosterol and sterol oleate. The Michaelis-Menten constants of linoleic acid and oleic acid treated by using the laccase/HBT system were 1.38 and 1.86 mmol/L, respectively, indicating that linoleic acid could be more easily combined with the laccase/HBT system; the optimum conditions for the treatment of linoleic acid with laccase included an enzyme dosage of 2.0 U/mg, and a 1-hydroxybenzotriazole mediator dosage of 7.6 mol/g, for 60 min, at 50 ℃, pH 4.0. The degradation rate of linoleic acid under these conditions was 88.9%; when the enzyme dosage was 4.0 U/mg or when the treatment time was 120 min, the degradation rate achieved 100%. Figures and Tables | References | Related Articles | Metrics

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Comprehensive Utilization Scheme and Economic Feasibility of Biomass Pyrolysis Products Xinchi ZHANG, Shanmei DONG, Yue WANG, Shiliang WU, Rui XIAO 2021, 41 (1):  100-106.  doi: 10.3969/j.issn.0253-2417.2021.01.014 Abstract ( 382 )   HTML ( 32768 )   PDF (688KB) ( 643 )   Save In this study, we developed an integrated scheme of biomass grading utilization, based on an agricultural park, by collecting straw biomass pyrolysis data, establishing a pyrolysis product database, and establishing an SVM biomass pyrolysis product model of the database. The product model was used to optimize individualized planting based on the scheme. When the treatment capacity was 400 kg/h, the scheme enabled disposal of 25%-50% of the returning straw, compared with that in the traditional straw-returning scheme. In the straw treatment project and fertilizer purchase, the park could save on nearly 30% of the related expenditure, and the optimization scheme could reduce expenditure by nearly 4%. Figures and Tables | References | Related Articles | Metrics

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Progress of Research on CO2 Adsorption by Porous Carbon Materials Yuhang ZHANG, Wei LI, Chunhui MA, Sha LUO, Shouxin LIU 2021, 41 (1):  107-122.  doi: 10.3969/j.issn.0253-2417.2021.01.015 Abstract ( 704 )   HTML ( 1782629672 )   PDF (6753KB) ( 790 )   Save Global warming caused by greenhouse gas emissions is a pressing environmental problem. Given that CO2 is the most significant greenhouse gas, research into materials that can efficiently adsorb CO2 has attracted considerable attention. Compared with other adsorption materials, porous materials offer a large specific surface area with high chemical and thermal stabilities and also feature good adsorption capacity, selectivity, cyclicity, and fast adsorption kinetics; therefore, they are widely used as solid adsorbents for CO2 capture. This review systematically introduces five types of porous carbon materials coal/petroleum-coke-activated carbons, biomass porous carbons, carbon aerogels, metal-organic-framework-derived carbons, and carbon nanomaterials that have been developed in recent years. Furthermore, the four primary methods used to prepare these materials for CO2 adsorption (i.e., high temperature carbonization and activation, hydrothermal carbonization, sol-gel processing and the template method) are presented. Emphasis is placed on their structure-performance relationship with CO2 adsorption. Simultaneously, the mechanism whereby CO2 is adsorbed by porous carbons with a pore texture is reviewed, in addition to the surface chemistry. Lastly, current challenges pertaining to CO2 adsorption are summarized, and future development trends are also prospected. Figures and Tables | References | Related Articles | Metrics

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Progress on Lignocellulose-based Magnetic Adsorbents for Removal of Heavy Metal Ions Xuan ZHOU, Can JIN, Guifeng LIU, Shuping HUO, Guomin WU, Zhenwu KONG 2021, 41 (1):  123-132.  doi: 10.3969/j.issn.0253-2417.2021.01.016 Abstract ( 478 )   HTML ( 1344317439 )   PDF (4982KB) ( 615 )   Save Pollution by heavy metals is a serious environmental problem. Lignocellulose offers the advantages of high-capacity storage, renewability, and biodegradability, while offering excellent adsorption performance and being easy to recycle. As such, it is being increasingly used as a magnetic adsorbent for the removal of metal ions from polluted water. Starting with a brief description of magnetic nanomaterials, this review focuses on the preparation of cellulose-, lignin-, and hemicellulose-based magnetic adsorption materials, both domestically and overseas, summarizing and comparing their abilities to adsorb different heavymetal ions. In addition, the adsorption abilities and factors influencing the removal of different heavy metal ions are discussed in detail. Finally, future development directionsfor lignocellulose-based magnetic adsorbents are discussed. Figures and Tables | References | Related Articles | Metrics