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Table of Content
05 July 2012, Volume 31 Issue 07
    Progress of preparation and applications of alkaline Ca-bentonite
    ZHANG Hanbing1,2,HU Xueling1,WEI Tengyou1,TONG Zhangfa1
    2012, 31(07):  1395-1401. 
    Abstract ( 1352 )  
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    Alkaline Ca-bentonite is a new kind of layered clay minerals with anion exchange performance. The preparation technology,characterization and preparation mechanism of alkaline Ca-bentonite are introduced,and the morphology,structure and behavior of raw bentonite,acid activated bentonite and alkaline Ca-bentonite are compared respectively. Furthermore,the applications of alkaline Ca-bentonite in adsorptive separation,catalytic reaction and composites preparation are also summarized. Finally,On the basis of the above analysis,the development of organic-inorganic composite wastewater treatment,solid catalyst preparation and bentonite intercalation compounds are proposed for further research of alkaline Ca-bentonite.
    Research progress of kiln phosphoric acid process
    DENG Shuyuan 1,LIANG Bin 1,LI Chun 1,Lü Li 1,WU Pan 1,QIU Liyou 1,WANG Liming 2
    2012, 31(07):  1402-1406. 
    Abstract ( 1176 )  
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    In order to promote the research and development of kiln phosphoric acid process,and based on the previous work of our group,this review systematically summarizes the basic research development and status of KPA process both at home and abroad,including reaction thermodynamics,phosphate rock reduction mechanism and dynamics. The research development of KPA process on the principle,key parameters and important engineering problems in the KPA process is introduced,and the outline of key techniques and its solution scheme are pointed out. In light of the problems existing in the KPA process,it is suggested to intensify basic research of the KPA process and to perform industrial experiments.
    Research progress of transport phenomena within photobioreactor for microalgae culturing
    CHEN Zhijie1,JIANG Zeyi1,2,ZHANG Xinxin1,3,ZHANG Xinru1
    2012, 31(07):  1407-1413. 
    Abstract ( 1072 )  
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    Transport phenomena within photobioreactor has a great impact on the growth rate and biomass production for mass cultivation of microalgae. This paper focuses on the transport phenomena within photobioreactor,including light distribution,heat transfer,mass and momentum transfer,and the research progress of mathematical models of each phenomenon. In this review,the effect of the type and scale of photobioreactor on light distribution,mass transfer and other phenomena is discussed,and the important parameters of each phenomenon,such as light absorption coefficient and volumetric mass transfer coefficient are summarized. The review would provide reference for the design,optimization and scale-up of high efficiency photobioreactor suitable for mass cultivation of microalgae.
    Research progress of gas dispersion in stirred vessel with medium or high viscosity fluids
    LI Hongxing1,WANG Jiajun2,FENG Lianfang2,JIN Zhijiang1
    2012, 31(07):  1414-1418. 
    Abstract ( 1345 )  
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    Research progress of air hold-up,bubble size distribution and gas-liquid mass transfer in stirred vessel with viscous fluid were summarized from the perspective of experiment and simulation. The influences of impeller,operating conditions,viscosity or non-Newtonian characteristics on gas dispersion were discussed. The combination of radical-flow impellers and up-pumping axial impellers could decrease the scale of air cavitation,and was suitable for low viscosity and moderately viscous fluids. The influence of agitation speed was more significant than air inflation rate. With increasing agitation speed,uniformity of bubble distribution became better. Increasing air inflation rate enhanced air hold-up occupied by big bubbles. The non-uniformity of air distribution became worse. Increasing viscosity or non-Newtonian capacity changed the rate of collision of bubbles,making mean bubble size smaller. Correction of computational model for viscous fluids was presented and the direction of future research was prospected.
    Research progress of humidification-dehumidification desalination process
    TAO Jun,GONG Jianguo,ZENG Sheng,SHAN Yan,JIN Tao
    2012, 31(07):  1419-1424. 
    Abstract ( 1315 )  
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    Humidification-dehumidification (HDH) desalination process serves as an important supplement to traditional desalination processes. In this work,HDH systems are classified according to the use of latent heat,material circulation,form of driving,heat and mass transfer methods and energy supply. Components of the HDH systems,such as humidifier,dehumidifier and energy supply module,were analyzed in detail. Performance indices of the HDH systems were summarized. Finally,design suggestions for HDH systems were proposed in terms of material,desalination technology,structural design,etc.
    Research progress in separation of bio-oils by extraction methods
    Lü Dongcan,LIU Yunquan,WANG Duo,YUAN Liang
    2012, 31(07):  1425-1431. 
    Abstract ( 1414 )  
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    The recent progress in separation of bio-oils by extraction worldwide was reviewed,and specifically,the extraction with water,extraction with organic solvents,reactive extraction,supercritical extraction,and extraction-column chromatography were discussed. The advantages and drawbacks of aforementioned extraction methods were summarized. Improvements in biomass fast pyrolysis itself,such as pre-treatment of feedstocks,pryolysis with catalysts,or multi-stage condensation of pyrolysis-vapor should be attempted to obtain bio-oils rich in target components to facilitate separation of bio-oils by extraction. New extraction methods,such as microwave extraction and ultrasonic extraction may be investigated to examine their effectiveness for bio-oils separation.
    Evaluation of dissolution of H2S in aqueous solution of organic alkanolamine
    ZHANG Jiaojing,SONG Hua,BAI Bing,WANG Lu
    2012, 31(07):  1432-1436. 
    Abstract ( 1638 )  
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    Using H2S/N2 to model natural gas,the effects of absorbent and absorbent concentration and temperature on vapor-liquid equilibrium were studied on a self-made small vapor-liquid absorbent equilibrium apparatus. Two chemical process flow simulation softwares of Aspen Hysys and Aspen Plus were used in simulation of the system. Good agreement between the measured results by this work and the result of computer simulation was obtained. The absorbed burden of absorbent was 3183.5 mg/L by using N-methyldiethanolamine (MDEA) as absorbent at absorbent concentration of 2.5 mol/L and absorbent temperature of 25 ℃.
    Efficiency of wood cellulose filtration
    ZHANG Yue1,XU Li1,DU Lihong1,2,ZHU Qixin1
    2012, 31(07):  1437-1441. 
    Abstract ( 1151 )  
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    Wood cellulose is widely used as a filter aid. Different filtration conditions greatly affect the filtration performance of the wood cellulose filter cake layer. In this paper,the influence of filtration pressure on retention efficiency and average filtration rate was studied with the single-factor method. The influence of viscosity of suspension,concentration of wood cellulose,amount of wood cellulose and water content on retention efficiency and average filtration rate was studied with orthogonal experiment. Experimental results showed that wood cellulose filter aid was a moderately compressible material and its filtration performance changed with filtration condition. The best filtration condition was determined by analyzing experimental results. The results provide a reference for small-scale industrial trials of filtration with wood cellulose.
    An experimental study on CO2 hydrate-based separation from flue gas with tetra-n-butyl ammonium bromide/cyclopentane solution
    ZHAN Hao1,2,XU Chungang1,2,LI Xiaosen1,YAN Kefeng1
    2012, 31(07):  1442-1448. 
    Abstract ( 1250 )  
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    Experiments for CO2 separation from flue gas (CO2/N2) are conducted with the one-stage hydrate method using TBAB (tetra-n-butyl ammonium bromide,C16H36NBr) and CP (cyclopentane,C5H10) as joint additives. The effects of TBAB and TBAB/CP on hydrate formation and separation efficiency were investigated and compared. The suitable conditions of 276.15 K and 2.0—3.3 MPa along with initial liquid gas volume ratio of 0.78 and the CP volume concentration of 0.6 % were obtained. Under such conditions,the gas uptake with TBAB/CP joint additives was 1.5—2.0 times higher than that in TBAB solution. Meanwhile,the CO2 concentration in residual gas phase could be decreased from 17% to 7%. The split fraction of 60%—70% was also higher than that of 40%—50% in pure TBAB solution. The result demonstrated that TBAB/CP system was evidently helpful for hydrate-based CO2 capture from the flue gast.
    Investigation on flow boiling heat transfer of non-azeotropic refrigerant mixture in microchannel
    Lü Fengyong,MA Hugen,HE Hongping,QI Lushan
    2012, 31(07):  1449-1453. 
    Abstract ( 1411 )  
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    The heat transfer characteristics in microchannel 0.86 mm in diameter for refrigerant mixture R32/R134a with three different mass proportions were studied and the effect of non-azeotropic working media with different mass proportions on heart transfer in the microchannel was investigated. The experiment result showed that when mass proportion was 35%/65%,flow boiling heat transfer was the best at low dryness fraction,while the effect of mass proportion on heat transfer was not obvious at high dryness fraction. Heat transfer resistance effect was not obvious at a high mass flux. Pressure drop was the largest when mass proportion was 15%/85%,and for the other two mass proportions,25%/75% and 35%/65%,pressure drop was relatively smaller.
    Determination and correlation of VLE data for methanol and trimethoxymethane system at 101.3 kPa
    LI Chunli,ZHANG Fengjiao,FANG Jing
    2012, 31(07):  1454-1457. 
    Abstract ( 1705 )  
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    Isobaric vapor-liquid equilibrium data for the binary system of methanol and trimethoxymethane (TMM) were measured at 101.3 kPa over the temperature range of 337-372 K using a double circulating vapor-liquid equilibrium still. The experimental data were thermodynamically consistent according to the Herington test and were correlated with the NRTL, Wilson and UNIQUAC models, respectively. All the models were satisfactorily correlated with the VLE data. The data calculated by the Wilson model were the best, and the average deviations of temperature and vapor-phase mole fraction of methanol were 0.57 K and 0.0092, respectively. These data would be helpful to engineering design.
    Separation of pyridines compounds from coking toluene and regeneration of adsorbents
    NIU Congcong1, CHEN Lijun1, ZENG Aiwu2
    2012, 31(07):  1458-1463. 
    Abstract ( 1356 )  
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    Denitrogenation of coking toluene was studied via gas phase-adsorption and NaY zeolite was used as adsorbent. The contents of pyridine and methylpyridine in coking toluene could be reduced from 5595 μg/g and 1633 μg/g to below 500 μg/g, when temperature of adsorption was 115 ℃. The breakthrough treatment capacities for raw powder adsorbent and shaped adsorbent were 12.44 g/g and 5.94 g/g respectively corresponding to the adsorption amounts of 0.90 mmol/g and 0.44 mmol/g. The results of TGA and 13C-NMR indicated that pyridines compounds could desorbed with steam at 250 ℃, but carbon deposit could not be totally desorbed. The adsorption and desorption behavior comparison of raw powder adsorbent and shaped adsorbent showed that shaped adsorbent had lower treatment capacity but higher deep denitrogenation ability than raw powder adsorbent.
    Macro kinetics of catalytic dehydrogenation of propane on platinum-stannum catalyst
    ZHANG Haijuan,LI Jianghong,ZHANG Shudong,WANG Zhenyu,ZHANG Xiwen
    2012, 31(07):  1464-1467. 
    Abstract ( 1615 )  
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    The experiment of catalytic dehydrogenation of propane on platinum-stannum catalyst was performed with integral fixed-bed reactor,under the reaction conditions of temperature of 580—640 ℃,pressure of 0.1 MPa and space velocity of 1000—6000 h-1. The rate equation on macro kinetics of catalytic dehydrogenation of propane was obtained. Through fitting experimental results,the parameters of macro kinetic were determined by the method of multiple liner regression. The activation energy of dehydrogenation of propane reaction was about 78.4 kJ/mol. The results of statistic test on macro kinetics model showed that the rate equation was rational and reliable.
    Research progress of hydrogen production with methanol steam reforming
    YAN Yuejun1,2,LIU Qibin1,SUI Jun1,JIN Hongguang1
    2012, 31(07):  1468-1476. 
    Abstract ( 1974 )  
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    Current research progress of methanol steam reforming with catalysts was reviewed. Different viewpoints on reaction mechanism and kinetics were summarized. Common catalysts used in the reaction were classified. Factors that influence the performance of the catalysts in the preparation and reaction stage were discussed. Several existing problems of the reaction were pointed out and two corresponding innovative trends were presented. One was methanol steam reforming technology driven by solar energy and the other was development of micro channel reactor for methanol steam reforming.
    Research progress on factors affecting VAPEX performance in exploitation of heavy oil and bitumen
    ZHAO Fajun1,2,LIU Yongjian1,WU Yongbin3,HA Si4,TAN Longri4
    2012, 31(07):  1477-1483. 
    Abstract ( 1344 )  
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    Since the exploitation of unconventional oil resources like heavy oil and bitumen is increasingly important due to gradual exhaustion of conventional light oil resources,the vapor extraction (VAPEX) technology in exploitation of heavy oil and bitumen deposits has become a promising process. This paper discusses the influence factors of VAPEX,including heavy oil viscosity,solvent diffusion and dispersion coefficients,solvent injection temperature and pressure,solvent injection rate,geological factors,etc. The critical mathematical equations and the mathematical model characterizing the relationship between the factors above and heavy oil/bitumen production rate are deduced. The outlook and development trend of VAPEX technology are analyzed,such as experimental model modification based on the difference between mathematical model and actual reservoir model,VAPEX combined with SAGD process,solvent diffusion coefficients at different temperatures and pressures,and application of mixed solvent systems.
    Progress of preparation and catalytic application of magnesium fluoride with high surface area
    NIU Huaicheng,LI Lichun,LI Ying,HAN Wenfeng,TANG Haodong,LIU Huazhang
    2012, 31(07):  1484-1492. 
    Abstract ( 1337 )  
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    This review outlines the synthesis,characterization and catalytic application of MgF2 (agnesium fluoride) based materials. The advantage and disadvantage are summarized. Such materials can be used in the systems involving corrosive gases and solvent due to its corrosion resistance and high stability. The catalytic reactions,are chlorine/fluorine exchange reactions,hydrogenation,hydrodechlorination of chlorofluorocarbon,hydrodesulfurization of organic compounds and removal of NOx. The catalytic application of magnesium fluoride itself is limited due to its low surface area and weak acidic properties. The recent development on the synthesis,catalytic application of MgF2 and supported solid acid catalysts is reviewed. Special attention is paid to the controlled synthesis of MgF2 (magnesium fluoride) with high specific surface area and tunable acid-base properties. Finally,the importance of research on the preparation of high surface area MgF2 and its application prospects in catalysis is pointed out.
    Research progress on selective catalytic reduction De-NOx catalysts
    GU Weirong,ZHOU Mingji,MA Wei,WANG Yuli
    2012, 31(07):  1493-1500. 
    Abstract ( 1273 )  
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    Selective catalytic reduction (SCR) has been the mainstream technology to control emissions of NOx. This tecnology has numbers of advantages,such as extrodinary selectivity, high denitration and no secondary pollution. In this paper,the research progress of SCR and the catalysts was presented. The vanadium-titanium catalysts,noble metal catalysts,metal oxide catalysts and zeolite molecular were focused. The situation of the industrialization of the De-NOx catalyst and the main factors of catalysts was analyzed. Finally the development of De-NOx catalyst should be to improve the catalyst life,product the new catalysts (especially the mixed metal oxide catalysts and the new vanadiumt-based catalysts) and new technology direction.
    Ultrasonic synthesis and characterization of Zr-pillared montmorillonite for MTO catalytic reaction
    WEI Zhaoni,CHEN Shufang,LIN Cheng
    2012, 31(07):  1501-1506. 
    Abstract ( 1184 )  
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    Zr-pillared montmorillonites (Zr-PILM) were prepared by irradiation with ultrasonic wave with montmorillonite as raw material and zirconium oxychloride as Zr source of pillaring agent. The properties of the Zr-pillared montmorillonites were characterized by XRD,BET,FTIR,SEM and Py-IR. The effects of synthesis conditions on the structures of Zr-PILM were investigated. The results indicated that Zr-PILM retained complete layered and flaked structure,and its interlayer spacing and BET surface increased. The acid strength of B and L acids of Zr-PILM reduced,which are more appropriate for the catalytic reaction of MTO. The Zr-PILM synthesized by ultrasonic irradiation exhibited excellent catalytic activity for MTO reaction. The methanol conversion reached 94.4 % and the selectivity of total light olefins in MTO reaction was 73.9%,under the condition of volumetric space velocity 1.2 h-1 and reaction temperature 360℃
    Preparation of nano-sized CuO-ZnO composite particles by UF membrane method and their catalysis performance
    ZHANG Chunfang,CHEN Xin,XU Jiong,BAI Yunxiang,GU Jin,SUN Yuping
    2012, 31(07):  1507-1511. 
    Abstract ( 1221 )  
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    A series of nano-sized CuO-ZnO composite particles were synthesized with a UF membrane reactor and were used for the oxidation of cumene reaction. It was found that CuO-ZnO prepared by the co-precipitation method had better catalyst performance than CuO/ZnO prepared by blending CuO with ZnO with the same ZnO content. The SEM results showed that ZnO was dispersed well in CuO in the case that the ZnO weight content in CuO-ZnO was 25%. The effect of ZnO content in CuO-ZnO on the catalytic performance for cumene oxide reaction was also investigated. With increasing ZnO content,catalytic performance reach a maximum value of CHP yield of 28% and selectivity of over 84.62% at ZnO weight content of 25% under the same reaction conditions:temperature,90 ℃; CuO-ZnO particle dosage 10 g/L;airflow rate 600 mL/min.
    Liquid-phase oxidation of toluene to benzaldehyde on Cr(Ⅲ)/HMS catalyst
    WU Juanjuan,MENG Lifen,MAO Liqiu,YIN Dulin
    2012, 31(07):  1512-1516. 
    Abstract ( 1417 )  
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    Cr(Ⅲ)/HMS catalysts were prepared by the impregnation method using Cr(NO3)3 as chromium source supported on HMS synthesized by the sol-gel method. The catalysts were characterized by XRD and FTIR. The effect of loading content of Cr and different chromium sources on liquid-phase oxidation of toluene to benzaldehyde with H2O2 was investigated. The results showed that chromium ion was incorporated into the framework of HMS. Cr(Ⅲ)/HMS catalyst with Cr-loading of 15% gave the best catalytic activity. The conversion of toluene and the selectivity for benzaldehyde reached 20.8% and 31.7% respectively. A reaction mechanism is proposed.
    Influences of carrier forming conditions on SCR denitration Mn-Ce/TiO2 catalysts at low temperature
    GENG Chunxiang1,LIU Wenrong1、2,ZHANG Binghua1,CHAI Qianqian1
    2012, 31(07):  1517-1520. 
    Abstract ( 1053 )  
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    Phosphoric acid solution was used as the raw material to make TiO2. The effects of adhesive proportion,calcination time,calcination temperature in the preparation process were investigated. The characteristics of the carrier were determined by using X-ray diffraction (XRD),surface detection system (BET) and scanning electron microscopy (SEM). The results showed that the carrier of the catalyst was in the form of anatase under the following conditions:drying temperature at 105 ℃,calcination temperature at 800 ℃,calcination time of 4 h.
    Research progress of halogen-free fire-retardant polyurethane foams
    ZHANG Xiaoguang,WANG Lieping,NING Binke,XUE Chao,SU Tianduo
    2012, 31(07):  1521-1527. 
    Abstract ( 1419 )  
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    The necessity and importance of halogen-free flame retardants for polyurethane foam (PUF) were presented. And the flame-retardant mechanism of PUF composites was introduced. Both the reactive and additive halogen-free flame retardants for polyurethane foams were summarized. Additive flame retardants included organic and inorganic additive. Additionally,expandable graphite (EG) as an intumescent flame retardant in polyurethane foams was reviewed. Finally,the development trend of the halogen-free flame retardants for PUF was prospected.
    Recent progress of synthesizing nano-structured conducting polymer by using block copolymers as templates
    Shalamaiti?Touhuti1, ZHANG Yanhui 1,Arzugul?Muslim 1,2
    2012, 31(07):  1528-1534. 
    Abstract ( 1356 )  
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    The domestic and overseas research progress of synthesizing nano-structured conducting polymers by using block copolymers as templates was reviewed. Nano-structured conducting polymers novel functional materials have become a hot research topic in recent years. Using block copolymers as templates is the most promising method of synthesizing this kind of materials. Therefore, the forming mechanism, experimental methods and influence factors of synthesizing nano-structured conducting polymers with regular morphology by this method were summarized. At the end, the problems existing in the research of nano-structured conducting polymers were presented. Using block copolymer as template would be beneficial to improving the controllability of the morphology and size of conducting polymers, and thus to improve such properties of conducting polymers as solubility, processability and conductivity.
    Research progress of visible-light-driven superhydrophilic TiO2 thin films
    HUANG Tao,HUANG Hong,SITU Yue
    2012, 31(07):  1535-1541. 
    Abstract ( 1323 )  
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    The mechanisms of TiO2 films superhydrophlicity are introduced. The methods for realizing visible-light-driven superhydrophilicity of TiO2 thin film,including constructing rough films,precious metal deposition,ion doping,surface sensitization,semiconductor coupling ,TiO2/SiO2 compositing and multiple modifications are discussed. In addition,the existing problems of superhydrophilic TiO2 are addressed,such as complicated preparation technology,rigid modification conditions and short time of superhydrophilicity. Using the sol-gel method and combining multiple modifications are effective methods to resolve these problems in the future.
    Review and prospect of zerovalent iron nanoparticles synthesized by chemical solution reduction process
    FAN Mingde1,2,YUAN Peng3,HE Hongping3,CHEN Tianhu4,
    2012, 31(07):  1542-1548. 
    Abstract ( 1527 )  
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    Zerovalent iron nanoparticles (ZVINs) have attracted much attention for their excellent magnetic properties and great potential in many practical applications. This review summarizes the details of synthesizing ZVINs by chemical reduction of iron salts in aqueous solution. ZVINs are easy to agglomerate and oxidize,which makes them difficult to prepare,study,and utilize. Agglomeration of ZVINs can be largely inhibited by stabilizing them with various dispersing agents and oxidation of ZVINs can be minimized by coating them with different shells. In the chemical solution reduction process,three kinds of reducing agents of hydrazine hydrate and polyols and alkali metal borohydrides with different reduction performance are often used to synthesize ZVINs. The advantages and disadvantages of these reducing agents for synthesizing ZVINs are discussed. Further developments of the chemical solution reduction process,to a great extent,depend on the insight into the behavior of dispersing agents and coated shells,on the industrial scale-up of the chemical reduction process,and on the low-cost preparation of ZVINs.
    Research progresses in intrinsic self-healing polymer materials
    LI Haiyan,ZHANG Libing,WANG Jun
    2012, 31(07):  1549-1554. 
    Abstract ( 1405 )  
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    The research status of self-healing polymer was reviewed. Self-healing method in polymer materials includes extrinsic self-healing(nanoparticles self-healing,microcapsules self-healing,hollow-fibers self-healing and microvessels self-healing,et al) and intrinsic self-healing(reversible covalent bond self-healing,reversible non-covalent bond self-healing). Research progress in intrinsic self-healing polymer materials in recent years is summarized. Reversible covalent bond self-healing method realized the function with the help acylhydrazone bond,disulfide-bond,N—O bond and Dieal-Alder reaction in polymer system. Reversible non-covalent bond self-healing method depend on the interaction of hydrogen bond,hydrophobically,static electricity,ionomers,molecular diffusion and metal-ligand. Intrinsic self-healing mechanisms and present research status were elaborated. The potential application fields of smart self-healing materials such as high-rise buildings,nuclear material storage and biology medical material are prospected.
    Preparation of polyvinyl acetate-grafted-calcium alginate beads
    QI Liangliang,YING Xiaoguang,LI Xiao,ZHANG Weiying,XU Wen
    2012, 31(07):  1555-1561. 
    Abstract ( 1308 )  
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    In order to reduce the swelling ratio of calcium alginate beads,vinyl acetate (VAc) was grafted on sodium alginate (SA) by free radical copolymerization,and vinyl acetate grafted calcium alginate (Ca-SA-PVAc) beads with low swelling ratio were prepared. FTIR indicated that new chemical bond was formed in modified alginate molecule. TGA showed that the rate of bound moisture loss of modified alginate beads was changed and its heat stability was improved. SEM showed that Ca-SA-PVAc beads had well-developed pore structure. The effects of reaction conditions,such as grafting reaction temperature,monomer and initiator concentrations,percentage of alginate and calcium chloride,grafting reaction time on swelling ratio in 0.9%NaCl solution were studied. By changing reaction conditions and consequently grafting reaction parameters,the swelling ratio of grafted beads could be controlled.
    Preparation of SiO2/polytetrafluoroethylene hybrid superhydrophobic coatings
    ZHENG Yansheng1,HE Yi2,QING Yongquan2,ZHUO Zhihao2,MO Qian2
    2012, 31(07):  1562-1566. 
    Abstract ( 1238 )  
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    Hydrophobic coatings were fabricated on glass substrate with SiO2 sol and polytetrafluoroethylene via the sol-gel process.SiO2 sol nanoparticles surface were modified with silane coupling agent ??-glycidoxypropy1 trimethoxysilane.The coatings were characterized by scanning electron microscope,Fourier transform infrared spectrometry,digital microscope and thermal synthetic analysis.The experimental results showed that coatings with hierarchical nano and micro structures exhibited hydrophobicity with a water average contact angle of 156°and sliding angle of 6°. ? -Glycidoxypropy1 trimethoxysilane enhanced the hydrophobicity of the coatings.Low surface energy of polytetrafluoroethylene and special structure of the coating were responsible for the hydrophobicity of the surfaces.
    Coalescence removal of residual free acid from bisphenol A resultant with fiber membrane
    TANG Xiaodong1,2,WANG Yan2,LI Jingjing2,LIU Haiyan2
    2012, 31(07):  1567-1570. 
    Abstract ( 1211 )  
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    The influence of reaction and recycling conditions for coalescence removal of residual free acid from bisphenol A resultant with fiber membrane were investigated. The experiment results showed that at 70 ℃,2% ethanol added,space velocity 20~30 h-1 and 1.0 cm3 fiber membrane bed,the bisphenol A resultant acidity decreased from 0.014mmol/L to 0.001 mmol/L,which met the acidity requirement for bisphenol A resultant . When the disposal amount of bisphenol A resultant reached 60 times of the fiber membrane layer volume,the layer must be recycled with acetone. By experiments,the best recycling temperature was 50 ℃ and acetone dosage was 6 mL.
    Application of data mining in preparation of nanometer TiO2
    LI Feng1,2,ZHENG Jingtang1,HU Yan1
    2012, 31(07):  1571-1574. 
    Abstract ( 1123 )  
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    Nanometer TiO2 photocatalysts were prepared with the sol-gel process. Their photocatalytic activities were evaluated by photodegradation of methyl orange (MO) in water under UV light irradiation. To obtain the data of preparation,orthogonal design was used. The relationship between photo-catalytic activity of TiO2 for methyl orange and preparation conditions could be mined by analysis of variance and support vector regression (SVR). The results indicated that not only the best scheme of preparing photo-catalysts,but also the sequence of factors affecting the photo-degradation activities of nanometer TiO2 on methyl orange could be found. The influence sequence from larger to smaller was calcination temperature and glacial acetic acid volume > distilled water consumption > alcohol amount. Through the comparing the tested value with the calculated value of SVR for test sample,the experimental data could fit the calculated value well. The activities of nanometer TiO2 optimization parameters could be identified and estimated by the methodcombining orthogonal Latin square design with SVR.
    Characteristics of polyurethane (PU) foam plastics bio-carrier modified by chemical oxidation-surface covering with iron ion
    DU Zhenfeng1,WANG Fen1,CHENG Guodong2,LIN Mengwei3,JI Min1
    2012, 31(07):  1575-1580. 
    Abstract ( 1358 )  
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    A surface modification method,chemical oxidation-surface covering with iron ion,was used to modify the polyurethane (PU) foam plastics bio-carrier. And surface properties of the bio-carrier,speed of biofilm formation,quantity of biological film and performance of treating wastewater were investigated before and after modification. The results showed that the ratio of the hydrophobic C—C,C—H bond on the surface of the modified bio-carrier was reduced by 15.81%,and the ratio of the hydrophilic C—O bond on the surface of the modified bio-carrier has increased by 16.17%. The dynamic contact angle of water against the bio-carrier surface was decreased by 10.46°. The surface roughness and hydrophilicity of the bio-carrier were enhanced. Comparing modified bio-carrier with the original bio-carrier,the quantity of biofilm increased by 60%,and the average growth rate of biological film increased by 50%. But the TTC-DHA of modified bio-carrier hardly increased. At the stage of biofilm formation,the performance of COD and ammonia removal of the modified bio-carrier was better than the original bio-carrier. After completion of biofilm formation,the removal efficiency of COD was almost the same,but the removal efficiency of ammonia increased by 10%.
    Research progress of biosynthesis of daptomycin and its derivative
    WAN Tao1,QI Haishan1,CHEN Yunlin2,WEN Jianping1
    2012, 31(07):  1581-1586. 
    Abstract ( 1170 )  
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    With continuous appearance of highly pathogenic bacteria which are resistant to antibiotics,the need for new antibiotics becomes much pressing in clinical medicine. As the first production of cyclo-lipotpeptied antibiotics daptomycin has effective bactericidal effect to antibiotic resistant bacteria. Because of its convenience in preparation and treatment,as well as insignificant side effects,daptomycin is the perfect replacement of vancomycin recognized as the last line of defense to pathogen. On the basis of introducing physical and chemical characteristics,antimicrobial activity and research achievement of synthetic genetic cluster of daptomycin,this paper mainly summarizes research situation of daptomycin and its derivatives. And the paper also presents perspectives about production of daptomycin and development of its derivatives,including combining with system biology to provide guidance for daptomycin strains’ further metabolic engineering improvement and utilizing synthetic biology to make derivatives of daptomycin new antibiotic.
    Research progress of silk fibroin microsphere as sustained-release carrier of drug
    DANG Tingting1,CHEN Aizheng 1, 2,WANG Shibin 1, 2
    2012, 31(07):  1587-1591. 
    Abstract ( 1574 )  
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    Silk fibroin (SF) is stable,non-toxic and cheap,and is an excellent carrier material due to its availability,biodegradability and biocompatibility. Based on its unique amino acids composition and stable structure of self-assembling ?-sheets,several methods for preparation of SF microspheres/microparticles are introduced,such as enzymolysis,spray drying,emulsification solvent evaporation,phase separation,electrospraying,as well as the new technologies of suspension-enhanced dispersion by supercritical CO2 (SpEDS),and their sustained-release characteristics as drug carriers are also reviewed. In addition,it is recognized that challenges remain,including variation of silk between species and between individuals of the same species and inconsistencies in the degumming process. The future direction could be developing modified,composite or genetically engineered SF proteins,which would have potential applications in the biomedical field.
    Ability of cation exchange resin H-732 as cataiyst for esterification
    ZHAO Zhigang1,SHAO Taili1,QIN Guozheng1,CHEN Kaoshan1,2
    2012, 31(07):  1592-1596. 
    Abstract ( 1409 )  
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    Catalytic ability of cation exchange resin H-732 for esterification reaction was investigated,and monoethyl ester of succinic acid and acetylsalicylic acid were synthesized by esterification reaction,and the optimum experimental conditions were optimized by single factor experiment and orthogonal experiment. The results of single factor experiment showed that under the following condition:the quantity of the resin :20% of succinic anhydride,n(ethanol)∶n(succinic anhydride)= 1.8∶1,reaction time 2 h,reaction temperature 90 ℃,the yield was 68.67%;. The yield of monoethyl ester of succinic acid was greatly improved by adding diethyl ester of succinate acid (side product) ,and the yield was 90.79%. The results of orthogonal experiment show that under the following condition:n(acetic anhydride)∶n(salicylic acid)= 3∶1, the quantity of the resin is 14.50% of salicylic acid,reaction time 2 h,reaction temperature 60℃,the yield was 77.57%. The catalyst lost its activity after reuse 5 times and its activity could be restored by re-activation.
    Research progress of chemical dephosphorization process
    LIU Ning,CHEN Xiaoguang,CUI Yanzhao,LIU Jianshe,XU Xiaoxue
    2012, 31(07):  1597-1603. 
    Abstract ( 1289 )  
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    Chemical phosphorus removal is an effective approach to controlling eutrophication and recycling phosphorous resource from waste water. The mechanisms of three major phosphorus removal reagents,such as ferric salt,aluminum salt and lime,were presented,and the influence factors of these three reagents,including pH,dosage,optimal dosing points and economic analysis,were also discussed. The processes of pre-chemical-aid,synergic-chemical-aid,post-chemical-aid and bypass-chemical-aid phosphorus removal technologies were summarized. The adsorption and crystallization phosphorus removal new process was introduced,and the prospect of recycling phosphorous resource as the development orientation of phosphate removal process in the future was presented.
    Emission and reduction strategies of greenhouse gases generated in municipal wastewater treatment plants
    GUO Jingbo 1,TIAN Yu2,ZHANG Lanhe2,MA Fang3
    2012, 31(07):  1604-1609. 
    Abstract ( 1414 )  
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    In recent years,great development has been made in wastewater treatment,resulting in annual increase in pollutants reduction capability of wastewater treatment plants. However,little attention has been paid to the greenhouse gases (GHGs) generated during wastewater and excess sludge treatment and disposal processes. The sources of GHGs generated from municipal wastewater treatment plants were demonstrated. In addition,reduction strategies of GHGs were proposed based on the selection of wastewater treatment process,scientific regulation and control of operation parameters,and treatment,disposal and reclamation of excess sludge as well as recycling of effluent, to provide guidance for further research on GHGs reduction and low-carbon operation in municipal wastewater treatment plants.
    Progress of effects of chloride on mercury removal for coal-fired flue gas
    YU Min,DONG Yong,WANG Peng,MA Chunyuan
    2012, 31(07):  1610-1614. 
    Abstract ( 1652 )  
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    燃煤电厂是最主要的人为汞排放污染源,氯元素对汞的形态转化及脱除率有非常重要的影响。本文概述了燃煤电厂汞的释放特性和现有控制技术,从氯元素作为烟气组分、活性炭改性物以及燃料添加剂这3个方面详细阐述了氯对汞排放控制的影响。首先氯化氢作为烟气组分,对单质汞向氧化态汞的形态转化有促进作用,这有利于现有除尘、脱硫装置对烟气汞的脱除。含氯化合物改性活性炭吸附剂时,物理吸附和化学吸附同时存在,这能有效提高吸附剂对汞的吸附性能。氯化物作为燃煤添加剂也能有效促进烟气汞的氧化和脱除,其中氯元素在湿法脱硫废水中富集,如何把其利用到烟气汞的脱除对开发高效脱汞技术有重要的意义。同时,比较了以上3种氯添加方案的优缺点。最后指出,深入研究氯元素对汞作用机理是今后的研究方向。
    COD and nitrogen removal with rotating biological contactor
    LI Fang1,2,CUI Hongmei1,2,Lü Bingnan3
    2012, 31(07):  1615-1619. 
    Abstract ( 1064 )  
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    A 3-stage rotating biological contactor was used to study simultaneous removal of COD and nitrogen. When temperature was 15 ℃ and influent COD concentration was about 400mg/L,removal rate of COD was about 85% . Through controlling proper alkalinity nitrification rate of ammonia was about 75% and removal rate of TN was about 50%. After addition of a nitrification liquid circulation system,removal rate of TN,at reflux ratio of 200% increased to 73.87 %. Experimental results showed good effect of rotating biological contactor on removing COD and nitrogen.
    Continuous extractive catalytic distillation to synthesize high-purity methylal
    LIU Hongzhong1,2,MA Yubo1,SHEN Xinquan 1,2,GAO Zhixian1,3,Wumanjiang Eli1
    2012, 31(07):  1620-1624. 
    Abstract ( 1396 )  
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    An integrated continuous process combining catalytic distillation and extractive distillation in one column was investigated for the synthesis of high-purity methylal from methanol and formaldehyde in the presence of cation-exchange resin catalyst. The experiments were carried out in a 2700 mm glass reactive distillation column (diameter of 35 mm),the effects of operating parameters,such as total feed rate,extractant feeding location,reflux ratio,formalin used as extractant on the continuous synthesis of methylal were studied. The results showed that formaldehyde conversion and purity of methylal in the distillate could reach 97.8% and 97.6%,respectively.