Table of Content

25 August 2019, Volume 39 Issue 4 Previous Issue    Next Issue

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Research Progress in the Removal of Biomass Tar Model Compounds Shuai MA,Xiaoying HU,Changqing DONG,Ying ZHAO,Xiaoqiang WANG,Jin ZHAO 2019, 39 (4):  1-8.  doi: 10.3969/j.issn.0253-2417.2019.04.001 Abstract ( 557 )   HTML ( 574 )   PDF (684KB) ( 688 )   Save The tar formed in the process of biomass gasification not only reduces the utilization rate of biomass energy while increasing the maintenance cost of system, but also affects the long-term stable operations of gasification system seriously. How to effectively remove the tar from gasification process has become an urgent problem for researchers. As the ingredients of biomass tar is very complex, it is of great importance to select appropriate model compounds that represent the characteristics of tar. Starting from the pyrolysis mechanism of the typical tar model compounds for, the removal pathways of tar model compounds are reviewed from experimental research and theoretical calculation. The reaction mechanism of tar catalytic cracking is summarized with transition metal catalyst as representative. Afterwards, the latest research progress in catalysts and plasma treatment of tar is reviewed and their characteristics are concluded. Finally, the prospect of technologies for efficient tar removal in future is discussed. Figures and Tables | References | Related Articles | Metrics

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Research Progress on Application of Cellulose-based Materials as Electrode in Flexible Supercapacitor Jianxiong XING,Kai ZHENG,Zunqiang HAN,Weitao XU,Kun WANG 2019, 39 (4):  9-17.  doi: 10.3969/j.issn.0253-2417.2019.04.002 Abstract ( 1143 )   HTML ( 159361 )   PDF (5661KB) ( 929 )   Save Cellulose has been increasingly utilized in the area of flexible supercapacitor, biosensor, and electromagnetic shielding because of its unique advantages of lightweight, biocompatibility and flexibility. The polyhydroxy structure of cellulose is beneficial for the transmission of electrolyte ions, resulting in the good performance of the electric capacity and cyclical stability for flexible electrode materials. Furthermore, flexible cellulose-based electrode can be obtained by coating, compounding, layer-by-layer self-assembling and in situ chemical polymerization with electroconductive materials(e.g., graphene, carbon nanotubes, conductive polymer and so on). Resent researches of the cellulose-based flexible electrode materials from different cellulose-based raw materials(original cellulose, nanocellulose and cellulose derivatives) were introduced in this review and the preparation methods and electrochemical properties of the obtained materials were also focused. The contributions of cellulose-based materials in the flexible electrode were categorized as:the backbone for supporting the flexible electrode material, the flexible substrates(or separator) and the ion channel for electrolyte. The future development and the challenges in the area of cellulose-based flexible electrode were also prospected. Figures and Tables | References | Related Articles | Metrics

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Preparation of Amino-terminated Hyperbranched Polymer Grafted Dialdehyde-based Nanocellulose and Its Adsorption Properties of Ni2+ Jinwei CHEN,Dan WANG,Shibin SHANG,He LIU,Zhaosheng CAI 2019, 39 (4):  18-26.  doi: 10.3969/j.issn.0253-2417.2019.04.003 Abstract ( 594 )   HTML ( 123 )   PDF (1230KB) ( 615 )   Save Amino-terminal hyperbranchedpolymer(HBP-NH2) was synthesized by polycondensation.Carboxylatednanocellulose(CNC) was prepared from eucalyptus pulp by using ultrasonic assisted 2, 2, 6, 6-tetramethylpiperidinyl-1-oxy (TEMPO)radical oxidation, and dialdehyde-based nanocellulose(DNC) was further obtained by sodium periodate oxidation of CNC. Finally, the amino-terminated hyperbranched polymer grafted dialdehyde-basednanocellulosematerial(HBPN-DNC) was prepared by amination modification of DNC with HBP-NH2. The reaction conditions were optimized. When the addition of 10% HBP-NH2 solution was 10 mL, the reaction temperature was 70℃, and the reaction time was 4 h, the N element mass fraction reached the highest, 6.0%. The structure and properties of nanocellulose were characterized by various methods. The results showed that the amino group was successfully graftedonto DNC. The molecular chain became longer and the thermal stability of the HBPN-DNC improved.The adsorption properties of Ni2+ on HBPN-DNC showed that, under the conditions of room temperature, 0.1 g of HBPN-DNC adsorbent, initial mass concentration of adsorption solution of 500 mg/L, pH value of 5 and adsorption time of 3 h, the adsorption capacity was 150.21 mg/g. The adsorptionfollowed the pseudo second order kineticsequation and Langmiur adsorption isotherm, which indicated that the adsorption process was mainly chemical adsorption of single molecular layer. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Antifungal Activity of (Z)-/(E)-Verbenone Oxime Ether Compounds Xiaoyu WANG,Wengui DUAN,Guishan LIN,Guoqiang KANG,Minghao SHANG,Fuhou LEI 2019, 39 (4):  27-34.  doi: 10.3969/j.issn.0253-2417.2019.04.004 Abstract ( 546 )   HTML ( 82 )   PDF (1017KB) ( 610 )   Save Verbenone was prepared by selective oxidation of α-pinene at first. Then, by oximation of the carbonyl group (Z)-and(E)-verbenone oxime compounds were synthesized and separaed, followed by the nucleophilic substitution reaction to afford forty novel (Z)-and (E)-verbenone oxime ether compounds 4a-4t, including twenty couples of Z/E isomers. The structures of the target compounds were characterized by 1H NMR, 13C NMR, FT-IR, UV-vis, and ESI-MS. The antifungal activities of the target compounds were evaluated. The results showed that, at the mass concentration of 50 mg/L, all the target products exhibited certain inhibition activities against the eight kinds of plant pathogens. Compound(E)-4r(R=2, 6-Cl) had inhibition rates of 77.8% against Physalospora piricola. Compound(E)-4s(R=2, 6-F) had inhibition rates of 72.7% against Rhizoctonia solani. Compound (E)-4n(R=p-CN) had inhibition rates of 70.8% against Helmithosporium maydis. Certain difference were found in inhibition activity of Z-E isomers against some plant pathogens. The CoMFA model(r2=0.992, q2=0.507) of (E)-verbenone oxime ether compounds for inhibiting Rhizoctonia solani was established for the study of 3D-QSAR, and the results could provide a basis for the design of potential lead compounds with higher activity. Figures and Tables | References | Supplementary Material | Related Articles | Metrics

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Preparation of Sliver Nanoparticles by Lignin Under Solar Light Irradiation Qingtong ZHANG,Xiaojing YUN,Depeng YAN,Mingfu LI,Shuangfei WANG,Douyong MIN 2019, 39 (4):  35-41.  doi: 10.3969/j.issn.0253-2417.2019.04.005 Abstract ( 519 )   HTML ( 7 )   PDF (13477KB) ( 375 )   Save Bagasse Kraft black liquor lignin was used as raw material to prepare lignin nanoparticles(LNPs) which was stably dispersed in water. Then, LNPs were used as reductant and stabilizer to reduce Ag+ into Ag nanoparticles(AgNPs) under ambient solar light irradiation. The optimal reaction conditions for the synthesis of AgNPs were the concentration of AgNO3:25 mmol/L, the mass concentration of LNPs suspension:100 g/L, and the solar light irradiation time of 10 min with the solar intensity of (900±100) W/m2. Under the optimal conditions, the average size of the synthesized AgNPs was 15.3 nm. HRTEM and element mapping analysis showed that the synthesized AgNPs were entangled by lignin. The electronegative groups of lignin provided AgNPs an abundant negative surface charge with the Zata potential of -24 mV.The electronic doubly layer repulsion hindered the aggregation of AgNPs and stabilized AgNPs in water. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Characterization of Allyl Cardanol Monomer with Ether Bond and Ester Bond Jian CHEN,Guomin WU,Shuping HUO,Zhenwu KONG 2019, 39 (4):  42-48.  doi: 10.3969/j.issn.0253-2417.2019.04.006 Abstract ( 647 )   HTML ( 457 )   PDF (670KB) ( 689 )   Save The allyl glycidyl ether modified cardanol(AGE-C) was prepared via reaction of cardanol with allyl glycidyl ether, and then the AGE-C was reacted with methacrylic anhydride to form allyl cardanol with ether bond and ester bond(MAA-AGE-C). The chemical structures of AGE-C and MAA-AGE-C were characterized by FT-IR, 1H NMR and 13C NMR. The results showed that the optimum conditions for the synthesis of allyl ether modified cardanol were as follows:the molar ratio of allyl glycidyl ether to cardanol was 1.2:1, the dosage of potassium hydroxide was 1% of the mass of cardanol, and the conversion of cardanol hydroxyl could reach over 95% at 100℃ for 2 h. The optimum conditions for the synthesis of allyl cardanol with ether bond and ester bond were as follows:the molar ratio of methacrylic anhydrideallyl to ether modified cardanol was 1.2:1, the dosage of 4-dimethylaminopyridine was 2% of AGE-C by mass, and the conversion of AGE-C hydroxyl could reach over 93.5% at 90℃ for 3 h. The hydroxyl and iodine values of AGE-C and MAA-AGE-C were 154 mg/g, 10 mg/g, 2.4 g/g and 2.1 g/g, respectively. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Characterization of Lignocellulose Oil-absorbing Aerogels Yan CHEN,Zixin WANG,Qizhen LI,Jianyu XIA,Zhulan LIU,Yunfeng CAO 2019, 39 (4):  49-55.  doi: 10.3969/j.issn.0253-2417.2019.04.007 Abstract ( 477 )   HTML ( 4 )   PDF (3032KB) ( 457 )   Save Soybean straw powder was swelled by ethanediamine(EDA) and dissolved in LiCl/DMSO solution to get a homogenies solution. In the homogenies solution, a novel hydrophobic oil-absorbing aerogel was fabricated from lignocellulose and monomers including methyl methacrylate (MMA) and butyl acrylate(BA) by the method of semi-interpenetrating polymer network (SIPN) with using N, N-methylene diacrylamide (MBA) as the crosslinker and azobisisobutyronitrile (AIBN) as the initiator. The chemical linkage, microstructure, rheology, hydrophobic and oil-absorption were determined by FT-IR, SEM, rheology tester, contact angle tester and so on. It could be concluded that the poly-(MMA-BA) matrix and lignocellulose chains were intertwined with each other in the aerogel and the aerogel had obvious porous three-dimensional network structure, good hydrophobicity and oil-absorption. The microstructure, hydrophobicity and oil-absorption could be regulated by adjusting the ratio of lignocellulose and the monomers. The lignocellulose aerogel obtained with the ratio of lignocellulose and monomers ratio of 1:4, had the loosest structure and relatively larger pores, and its absorption capacity on xylene and edible oil could reach up to 10.61 g/g and 7.41 g/g respectively, and these data were higher than those of others. Figures and Tables | References | Related Articles | Metrics

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Preparation of Activated Carbon from Co-pyrolysis Char of Sewage Sludge and Poplar Sawdust and Its Application in Wastewater Treatment Shaoji WU,Kun JIANG,Yueyuan YE,Yunquan LIU,Duo WANG,Shuirong LI 2019, 39 (4):  56-64.  doi: 10.3969/j.issn.0253-2417.2019.04.008 Abstract ( 544 )   HTML ( 31 )   PDF (1709KB) ( 626 )   Save The co-pyrolysis chars of sewage sludge and poplar sawdust were activated by using KOH chemical activation method to produce activated carbons(AC). The physical properties of obtained activated carbons were characterized. It was found that the surface area of activated carbon reached 551.0 m2/g and the total pore volume was 0.294 cm3/g, and most of pores were microporous.The phenol-adsorption experiments indicated that the activated carbon was very effective in removing phenols when phenol solution was used as the model of phenol-containing wastewater. It was also found that the phenol removal rate of 80.6%was achieved at the AC addition ratio of 1.75 g/L when the mass concentration of phenol solution was 50 mg/L.Furthermore, the adsorption of phenols could be enhanced at weakly acidic condition of pH 5. Finally, the fitting of experimental data showed that the adsorption of phenols with the prepared AC could be described by pseudo-second order kinetic law, while its adsorption isotherm could be simulated with the Langmuir model.Thermodynamic study showed that ΔHΘ and ΔSΘ were negative, and ΔGΘ ranged from -0.383 to -0.109 J/mol, indicating that the adsorption of phenol was a spontaneous, exothermic, entropy-decreasing, and physical-adsorption dominant process. Figures and Tables | References | Related Articles | Metrics

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P-factor Regulation of Characteristics in the Auto Hydrolysis ofPoplar Carbohydrate Pengfei WANG,Hao REN,Huamin ZHAI 2019, 39 (4):  65-71.  doi: 10.3969/j.issn.0253-2417.2019.04.009 Abstract ( 470 )   HTML ( 6 )   PDF (582KB) ( 467 )   Save To regulate carbohydrate reaction in the poplar autohydrolysis of biorefining, the effects of different P-factors on the pH value, hydrolysis rate, reducing sugar, holocellulose, different monosaccharides and furfural product in the poplar autohydrolysis system were studied in detail. The results showed that with the increase of P-factor to about 2 800, the pH value of the system decreased continuously to 3.6, the total hydrolysis rate and holocellulose removal rate reached 47% and 54%, respectively. Arabinose and rhamnose in pentosan were almost completely hydrolyzed, xylan was mostly hydrolyzed, and the removal rate of glucan was 37%(mostly from hemicellulose). The trend of total hydrolysis, holocellulose removal and pentosan removal could be divided into a fast and a following slow removal phase in the process. There was a positive correlation between P-factor and furfural production, which could be divided into a slow and a fast phase, and the conversion of pentose to furfural was 40%. P-factor could regulate the autohydrolysis of carbohydrate in poplar. Figures and Tables | References | Related Articles | Metrics

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Preparation of Nanocrystalline Cellulose by the Catalytic Hydrolysis of Pulp with p-Toluenesulfonic Acid Under Ultrasonication Mingcheng XIONG,Zi WANG,Yuxin YAN,Yanling ZHENG,Zhenzhen XIAO,Qilin LU,Biao HUANG 2019, 39 (4):  72-76.  doi: 10.3969/j.issn.0253-2417.2019.04.010 Abstract ( 507 )   HTML ( 5 )   PDF (1966KB) ( 506 )   Save A new type of high-efficiency and environmentally-friendly NCC was prepared by the catalytic hydrolysis of fiber raw material with p-toluenesulfonic acid. The effects of reaction time, reaction temperature and ultrasonication on the yield and properties of NCC were investigated. Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), transmission electron microscopy(TEM) and thermal gravimetric analysis(TGA) were used to characterize the spectral properties, crystal structure, morphology and thermal stability.The results showed that the NCC yield was the highest(51.66%) at the condition of reaction time of 45 min, reaction temperature of 80℃ and ultrasonic wave time 2 h. The TEM results indicated that the diameters of NCC were 10 to 40 nm and the lengths were 400 to 700 nm. XRD analysis showed that the crystallinity of NCC was 72.50%, which was higher than that of fiber raw material, and both of them maintained cellulose Ι structure.TGA displayed that the thermal properties of NCC were more stable than raw fiber. Figures and Tables | References | Related Articles | Metrics

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Effects of Different Drying Methods on Physicochemical Properties and Essential Oil Quality of Melaleuca alternifolia Cheel Yijun LIU,Yuan YUAN,Yangyang LIU,Fan ZHANG,Jihua LI 2019, 39 (4):  77-82.  doi: 10.3969/j.issn.0253-2417.2019.04.011 Abstract ( 472 )   HTML ( 5 )   PDF (457KB) ( 515 )   Save The effects of four drying methods, sun drying, hot air drying, vacuum drying and vacuum freeze drying on physicochemical properties and essential oil quality of Melaleuca alternifolia Cheel were studied. The results showed that the contents of flavonoids was the highest in M. alternifolia after hot air drying and the contents were(2.68±0.27)%; the DPPH·and ABTS+ scavenging activities of the M. alternifolia after freeze-drying were the lowest and the scavenging rates were (53.74±4.58)% and (71.63±2.95)%, respectively. After drying by four methods, the extraction rates of essential oil decreased. The oil extraction rate was the highest after the freeze drying. The contents of terpinen-4-ol and 1, 8-cineole in the essential oil obtained were higher than 30% and less than 5%, respectively after drying process. The difference of the contents of terpineol-4-ol in the essential oil obtained after sun drying and hot air drying was significant, and the content obtained after the sun drying was the highest. The content of 1, 8-cineole in the essential oil obtained after vacuum freeze drying was the lowest. Figures and Tables | References | Related Articles | Metrics

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Preparation and Physicochemical Properties of Olive Leaf Extract Xiaojie WANG,Lixin HUANG,Caihong ZHANG,Pujun XIE,Yejun DENG,Lujie LIU 2019, 39 (4):  83-90.  doi: 10.3969/j.issn.0253-2417.2019.04.012 Abstract ( 570 )   HTML ( 12 )   PDF (589KB) ( 651 )   Save The scale-up experiment of hot reflux extraction of total polyphenols, total flavonoids and oleuropein from olive leaves was studied. The effect of ethanol concentration on the extraction of active substances was investigated, and the related kinetics was also evaluated by ExpDec1 model. The results showed the highest contents of total polyphenols, total flavonoids and oleuropein were obtained when the ethanol concentration was 80% and they were 3.77, 2.85 and 3.03 g/L, respectively. ExpDec1 model had a good fitting effect, and the fitting degree R value was higher than 0.9. The higher ethanol concentration, the better the fitness effect observed. Under the condition of inlet temperature 150℃ and feeding rate 15 mL/min, the extracts were dried by spray drying, and crude extracts were purified by AB-8 macroporous resin, the content of total polyphenols increased from 9.71% to 31.65%, the content of total flavonoids increased from 7.22% to 10.98%, and the content of oleuropein increased from 9.16% to 20.38%. The physicochemical properties of the extract powder were measured, such as moisture content, porosity, density, dissolution, moisture absorption, active substance, etc. The results showed that moisture content, density and porosity of different extracts were similar, water extract had better water solubility(98.38%), 80% ethanol extract had higher content of the active substance(the contents of total polyphenols, total flavonoids and oleuropein were 9.71%, 7.22% and 9.16%, respectively), and the contents of total flavonoids and oleuropein were about two times higher than that of other solvents. Figures and Tables | References | Related Articles | Metrics

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Purification of Bletilla striata Polyphenols by Macroporous Resin and Its Antioxidant Activities in Vitro Yan PENG,Kehua TANG,Aiwen DONG 2019, 39 (4):  91-99.  doi: 10.3969/j.issn.0253-2417.2019.04.013 Abstract ( 459 )   HTML ( 5 )   PDF (726KB) ( 692 )   Save The static adsorption and desorption effects of ten kinds of macroporous resins on B. striata polyphenols crude extract were compared, and the optimal process of purifying with LSA-21 resin was discussed. Furthermore, the antioxidant activities of the pre- and post-purification B. striata polyphenols were tested in vitro. The results showed that, at room temperature, the optimal process parameters for adsorption of crude extract with LSA-21 resin were as follows:the mass concentration of polyphenol crude extract 0.4-0.6 g/L, pH vlaue 4, and the loading velocity 2.0 mL/min. The optimal process parameters for desorption were as follows:desorption solution ethanol volume fraction 80%, pH vlaue 6, and elution flow rate 1.0 mL/min. The purity increased from 4.48% to 27.61% after purifying 100 mL of 0.47g/L crude extract under the optimal technological conditions, and the purification effect was good. The DPPH·scavenging activity of the purified B. striata polyphenols was obviously improved. The IC50 of DPPH·、OH· and O2-·free radicals were 7.72, 8.65 and 205.39 mg/L respectively. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Characterization of Cardanol-based Epoxy Resin Containing A Cyclotriphosphazene Core Junjie LI,Yun DONG,Huaping ZHAO,Hongxia MA 2019, 39 (4):  100-104.  doi: 10.3969/j.issn.0253-2417.2019.04.014 Abstract ( 484 )   HTML ( 6 )   PDF (489KB) ( 476 )   Save A novel six armed cardanol-derived epoxy resin containing a cyclotri phosphazene core(EHCPP) was successfully synthesized by two steps. Firstly, cardanol reacted with hexachlorocyclotriphosphazene(HCCP) to produce hexasubstituted cardanol with cyclotriphosphazene core(HCPP) with NaH as acid binding agent; secondly, EHCPP was generated by epoxidation of HCPP with the H2O2/HCOOH system, the synthesis conditions of EHCPP were optimized by orthogonal experiment, and the intermediate product HCPP and the final product EHCPP were analyzed and characterized by FT-IR and 1H NMR. The results showed that the optimum synthesis conditions of EHCPP were as follows n(double bond of cardanol):n(formic acid)=1.0:1.0, n(double bond of cadanol):n(H2O2)=1.0:1.8, catalyst TsOH 1% relative to the mass of HCPP, the reaction temperature 65℃, the reaction time 6 h, and the results of FT-IR and 1H NMR analysis showed that the structures of HCPP and EHCPP were basically consistent with the expected structures and its epoxy value was 4.1 mmol/g. Figures and Tables | References | Related Articles | Metrics

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Antioxidant Activity of Tea Seed Shell Fermentation Extracts and Its Inhibitory Effect on Intracellular Oxidative Damage Jing ZHOU,Yuhao GUI,Shengzhao GONG 2019, 39 (4):  105-112.  doi: 10.3969/j.issn.0253-2417.2019.04.015 Abstract ( 467 )   HTML ( 5205 )   PDF (746KB) ( 652 )   Save Tea seed shell(TSS) were fermented with Aspergillus niger, Bacillus subtilis and Saccharomyces cerevisiae, by using immobilized cell fermentation technology, and the water extract of the fermentation product was prepared. The analysis showed that compared with the unfermented water extract, the content of main antioxidant substances in the fermented extract of S. cerevisiae (FETSS-3) increased significantly, the content of polysaccharides, polyphenols and saponins increased to 9.19, 9.59 and 4.67 times respectively. Its antioxidant activity was investigated by biochemical level, cellular level and enzyme activity level, and its skin safety was confirmed by patch test. The results showed that in the concentration range of 0.1-0.4 g/L and 0.5-2.0 g/L, ABTS and·OH radical scavenging activities of FETSS-3 were significantly superior to those of VC(P < 0.01; P < 0.01); In the concentration range of 0.2-1.2 g/L, its IC50 was only 21.98% of that of VE, and its inhibitory activity was significantly higher than that of VE(P < 0.01). In the concentration range of 20-120 mg/L, FETSS-3 could significantly reduce the level of oxidative damage stress of human skin fibroblasts(HSF) induced by H2O2(P < 0.01). In vitro enzyme activity experiments showed that FETSS-3(120 mg/L) could significantly improve the activity ofcatalase(CAT), superoxide dismutase(SOD) and glutathione peroxidase(GSH-PX) in HSF cells after oxidative stress injury(P < 0.05; P < 0.01; P < 0.01). The human body patch experiment showed that the FETSS-3 had no risk of skin allergy. Figures and Tables | References | Related Articles | Metrics

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Preparation and Properties of UV-curable Urushiol-cerium Polymer Coatings Wan ZHAO,Qianwen CAO,Haitang WU,Xiaohua HUANG 2019, 39 (4):  113-119.  doi: 10.3969/j.issn.0253-2417.2019.04.016 Abstract ( 397 )   HTML ( 5 )   PDF (2186KB) ( 477 )   Save Urushiol-cerium polymer (UCeP) coatings were prepared via UV-curing process without initiator using CeCl3 and urushiol as raw materials. The structure and thermal stability of the coatings were characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermal gravimetric analysis (TG). The effects of CeCl3 amount on the physical-mechanical properties and chemical medium resistance of the polymer coatings were investigated. The electrochemical impedance spectroscopy (EIS) tests were also carried out on the prepared urushiol-cerium coatings. The results showed that under the irradiation of UV urushiol hydroxyl coordinated with cerium ions, meanwhile, the unsaturated bonds in the side chain of urushiol underwent cross-linking polymerization, resulting in the curing of the coatings. Doping CeCl3 could significantly improve the thermal stability and alkali resistance of raw lacquer(RL) film. With the increase of CeCl3 amount, the adhesion, hardness and corrosion resistance of the coatings first increased and then decreased. The hardness and adhesion of urushiol-cerium polymer coating with the CeCl3 amount of 18% reached 6H and 1 grade, respectively, and its corrosion resistance was the best. Figures and Tables | References | Related Articles | Metrics

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Preparation of Lignin-based Carbon Material and Adsorption Mechanism of Cr(Ⅵ) from Wastewater Yongchang SUN,Bingqing ZHANG,Liming LIU,Xiaonan LIU,Zhengjun SHI 2019, 39 (4):  120-128.  doi: 10.3969/j.issn.0253-2417.2019.04.017 Abstract ( 492 )   HTML ( 7241 )   PDF (1752KB) ( 664 )   Save The industrial residue corncob lignin(CL) was used as raw material and activated by phosphoric acid, potassium hydroxide, and zinc chloride, respectively, to obtain lignin-based carbon materials, PA-CL, PH-CL and ZC-CL.And the carbon materials were used for adsorbing the chromium(Cr(Ⅵ)) ions from wastewater. Results showed that phosphoric acid activation process was simple, environmentally friendly and the activation temperature was low. And the phosphoric acid activated sample had higher adsorption efficiency for Cr(Ⅵ) than NaOH and Zncl2 activated samples. The removal efficiency of Cr(Ⅵ) by using PA-CL reached 79.2% in the first 5 min and 96.5% in 40 min with the initial Cr(Ⅵ) mass concentration 50 mg/L and adsorbent dosage 0.05 g at 50℃. The structural features of carbon material were analyzed by FT-IR and SEM and the functional groups on the surface of carbon materials were tested by the Boehm titration. The results showed that the phosphate group was introduced onto the surface of PA-CL and the total acidity increased to 3.20 mmol/g from 2.54mmol/g(original lignin), which was beneficial to adsorption of Cr(Ⅵ). The adsorption was described well with the pseudo-second-order model with qe of 390.6 mg/g and R2 of 0.991 0, for PA-CL. And the adsorption isotherm conformed to the Langmuir model with R2>0.9, which indicated that the adsorption of Cr(Ⅵ) on PA-CL was chemical adsorption-based monolayer adsorption. Figures and Tables | References | Related Articles | Metrics