The Chinese Journal of Process Engineering

Suspension of Solid Particles by Side-entering Agitators

ZHENG Xiao-dong; HUANG Xiong-bin; DOU Rong-li

. 2009, 9(3): 417-423.

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The influences of location of agitators, gas flow rate, solid particles content and liquid level on solid suspension of particles were studied in a tank of f2 m′4.2 m with side-entering agitators. The results show that the angle of agitator axis deviation from radial direction has little influence on power number. The optimum arrangement of agitators is symmetrical and the optimum angle 10o. The minimum just-suspension speed appears at L/d (entering length of agitator to diameter of impeller)=1.44. Compared with the conventional h (installing height of agitator)=1.5d, 30% energy consumption can be saved when the agitator is installed at a height of h=0.75d. When the ratio of liquid level to diameter of vessel (H/T) is less than 0.5, NJS increases rapidly with incresing of H. The relationship between NJS and gas flow rate (QV) and the influence of solid content w on NJS have been obtained respectively, NJSG-NJS=1.46QV1.15 and NJSμw0.27.

Mass Transfer and Kinetics in Preparation of Light Magnesium Carbonate by Stream-recycling Carbonation

YI Hong CHI Ru-an ZHU Guo-cai ZHAO Yu-na ZHAO Yu-na TIAN Jun

. 2009, 9(3): 424-430.

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The mass transfer and kinetics on the preparation process of light magnesium carbonate by stream-recycling carbonation were studied. The influences of gas flow, distribution proportion of gas and particle size, etc., on the process of stream-recycling carbonation were examined. At the same time, its model of stream-recycling reaction was built theoretically. The results show that the process of stream-recycling carbonation is controlled by diffusion mass transfer within 10~25℃, of which activation energy is 18.6 kJ/mol, while controlled by diffusion mass transfer and surface chemical reaction altogether within 25~35℃, of which activation energy is 33.15 kJ/mol.

Experimental Study on Phase Holdup in Three-phase External Loop Airlift Reactors Using Electrical Resistance Tomography

HAN Yu-huan JIN Hai-bo;

. 2009, 9(3): 431-436.

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Profiles of phase holdup in a f90 mm three-phase external loop airlift reactor using electrical resistance tomography and pressure transducers were investigated, water was used as the continuous and conductive phase, while polyurethane and air were non-conductive solid and gas phases, respectively. The results show that the gas holdup and solid holdup increases with the increase of superficial gas velocity, the solid holdup first increases with increasing superficial gas velocity and when ug=0.09 m/s, a constant value. For the fluidized system, the distribution of local solid and gas holdup shows a maximum at r/R=0~0.2, the radial gas and solid holdup increases with increase of gas velocity in the riser, while the radial gas and solid holdup is uniform in the downer. The feasibility of using the two techniques combined to measure the three-phase has been demonstrated.

Agglomeration of Inhalable Particles in Gas Jet

SUN De-shuai GUO Qing-jie SI Chong-dian

. 2009, 9(3): 437-440.

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A turbulent gas jet was introduced in an agglomeration chamber to generate a local turbulent flow field and intensify agglomeration process of inhalable particles. Aerosol cascade impactor and laser particle counter were used to measure the mass and number variations of particles after agglomeration. The parameters influencing particle agglomeration were examined in detail. The experimental results showed that the removal efficiency increased with increasing Reynolds number of jet exit and flow ration of jet-crossflow. However, the removal efficiency was affected by particle diameters, and the maximum efficiency observed in small particles (<1.0 mm). When relative humidity in the chamber approached 40%~50%, the maximum removal efficiency was acquired, in which the mass diameter increased from 2.83 mm to 5.03 mm. Increment of initial concentration of fly ash could resulted in decreasing of removal efficiency of inhalable particles.

Oxygen-rich Leaching of Sphalerite Concentrate under Normal Pressure

CHENG Yong-qiang QIU Ding-fan WANG Chen-yan YIN Fei

. 2009, 9(3): 441-448.

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Oxygen-rich leaching of sphalerite concentrate under normal pressure in a reactor was carried out. The optimal processing conditions were achieved as follows: particle size of more than 92% minus 44 mm, temperature of 373 K, agitator speed of 800 r/min, ratio of liquid to solid 5 mL/g, initial zinc concentration of leaching solution of 0.76 mol/L, ratio of sulfuric acid concentration to zinc concentration H2SO4/Zn at 1.27, oxygen partial pressure of 0.3 MPa, and leaching time of 5 h. The leaching rate of zinc was above 95%. The technological mineralogy of sphalerite concentrate and leaching residue was studied. The results indicated that the main reaction during leaching of sphalerite was ZnS+2H+?Zn2++H2S. The sulfuretted hydrogen was oxidized to sulfur.

Recovery of Acetic Acid with Ion Exchange Resins

QIU Ting HAN Shu-cui WU Yan-xiang

. 2009, 9(3): 449-455.

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Using ion exchange resins to recover acetic acid, the adsorption process was studied systematically. Through the resin selection experiments, D311 resin showed a better capacity and smaller constriction. The adsorption and desorption process of dilute acetic acid were studied with the selected D311 resin, and the optimized operation conditions were obtained. When the temperature was 30.0℃ and the feed velocity 4.0 mL/min, the adsorption rate reached 93.97%. When the temperature was 50.0℃, and the concentration of NaOH 3.98 mol/L, velocity 1.0 mL/min, the desorption rate reached 100%. Moreover, the resin regenerative experiments indicated that D311 resin regeneration had good repetition and excellent mechanical strength.

Preparation of Pluronic-based Magnetic Nanoparticles and Their Application in Purification of Laccase

LIU Xing-hua GUO Chen YANG Liang-rong WANG Feng LIU Chun-zhao LIU Hui-zhou

. 2009, 9(3): 456-461.

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Nano-sized monodispersed Pluronic (PEO-PPO-PEO)-based magnetic nanoparticles (PMNPs) were synthesized as carriers for the purification of laccase from the mycelium culture of Trametes versicolor. The adsorption assay was carried out in model system of laccase. The result showed that the maximum adsorption capacity was 0.535 mg/mg without any decrease in the range from 5℃ to 40℃. Purification of laccase from mycelium culture by PMNPs was also investigated. Total enzyme activity recovery rate could reach 62.9% with a single step, and purification fold 3.4.

Kinetics Research on Recovery of Vanadium from Bayer Process by Ion Exchange with Resin

ZHAO Zhuo LI Xiao-bin ZHAO Qing-jie

. 2009, 9(3): 462-467.

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Static adsorption kinetics of sodium vanadate by 201′7 resin was studied, and the adsorption mechanism analyzed. The sodium vanadate was prepared by precipitating vanadium from spent liquor of Bayer process and then leached. In optional reaction system, the influences of granularity of resin, temperature, stirring speed and concentration of sodium vanadate on the ion exchange process were investigated by batch ion exchange method. Moving boundary model was applied to describe the kinetics of ion exchange process. The results showed that the dominant procedure was ion diffusion through particles. The influences of stirring speed and temperature on the adsorption were little, the adsorption rate increased with the rise of primary consistency of sodium vanadate. The rate constant of exchange (k0), order reaction (n) and the apparent activation energy (Ea) were obtained: k0=10.052 cm4/(mol×s), n=0.5507, Ea=39.67 kJ/mol. The results of adsorption mechanism analysis show that the main anion of vanadium adsorbed by 201′7 resin during the kinetic experiments was V10O286-.

Recovery of Iron and Zinc from Blast Furnace Sludge

LI Liao-sha LI Kai-yuan

. 2009, 9(3): 468-473.

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The reduction roasting and weak magnetic separation techniques were adopted to recover high grade iron-rich ore from blast furnace sludge, and in the roasting process, CH3COOH solution was used to reclaim zinc in a by-product of Zn(CH3COO)2. The optimum conditions were obtained as follows: temperature 1373.2 K, and time 60 min. Through the reduction roasting, the dezincification rate reached up to 98%, a high grade iron ore with only 0.04% zinc was obtained. By weak magnetic separation 80% iron rich ore was obtained, the purity of Zn(CH3COO)2 reached 98.7%. The iron ore could be directly used in industries.

Influential Factors of Nitrogen Removal with Combined Biofilm Reactor

WANG Hong-xi LIU Jun-liang YANG Kai WANG Hong-yu

. 2009, 9(3): 474-479.

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The impacts of hydraulic retention time (HRT), dissolved oxygen (DO) and recycling flow rate (R) on performance of nitrogen removal were studied in the treatment of domestic sewage using combined biofilm reactor. The results showed that without recycling of effluent, HRT and DO affected the removal of ammonia nitrogen obviously while had little influence on removal of total nitrogen. After recycling started, the removal rate of TN increased greatly. Under the conditions of temperature at 19~28℃, COD concentration of 208~496 mg/L and NH4+-N concentration of 29.5~89.5 mg/L, respectively, the best removal efficiencies of NH4+-N and TN could be obtained at HRT of 3 h, R of 150%, DOO of 3~4 mg/L and DOB of 6~7 mg/L, respectively. The average removal rates of NH4+-N and TN were 98.97% and 76.27%, respectively, while the effluent concentrations of NH4+-N and TN were 0.43 and 11.2 mg/L, respectively, and met with the strictest requirement of discharge standard of GB18918-2002.

Decolorizing Kinetics of Caramel in Molasses Alcohol Wastewater Degraded by Low-grade Pyrolusite

SU Hai-feng CUI Qing-yan WEN Yan-xuan TONG Zhang-fa

. 2009, 9(3): 480-485.

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The caramel in molasses alcohol wastewater was simulated with synthesized diploid caramel, and the decolorizing kinetics of its oxidation degraded by low-grade pyrolusite studied. The effects of reaction temperature, pyrolusite dosage, initial concentration of caramel and sulphuric acid on the decolorizing rate of caramel were investigated. The results showed that the decolorizing rate increased with the increase of reaction temperature, pyrolusite dosage, initial concentration of caramel and sulphuric acid. The experimental data for the decolorizing rate of caramel were analyzed, and the kinetic model established. The apparent activation energy was calculated to be 24.4 kJ/mol, and the reaction order of caramel, sulphuric acid and pyrolusite were 2.0, 0.58 and 1.09, respectively.

Adsorption of Copper Ion by Calcined Acid Leaching Residue of Asbestos Tailing

CHEN Jun-tao ZHENG Shui-lin WANG Cai-li TAN Zhu-hong ZHENG Li-ming ZHENG Li-ming

. 2009, 9(3): 486-491.

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The acid leaching residue of asbestos tailing was pretreated by calcination, and the adsorption capability of calcined acid leaching residue of asbestos tailing to Cu2+ was studied. The x potential of acid leaching residue of asbestos tailing was mensurated, the unadsorbed and adsorbed Cu2+ acid leaching residues of asbestos tailing were characterized by SEM, TEM and FT-IR spectra, and the adsorption mechanism of acid leaching residue was discussed. The results showed that the isoelectric point of acid leaching residue of asbestos tailing was 2.03, the removal effect of Cu2+ was optimal when the quantity of adsorbent was 3 g/L, adsorption time 60 min, adsorption temperature 25℃, and pH value of solution 4.85. The model of isothermal adsorption accorded with Langmuir equation, which was chemical adsorption, the adsorption isotherm was Ce/q=0.0749Ce+0.1076. The adsorption mechanism of acid leaching residue to Cu2+ could be explained by both adsorption of surfacial coordination and ion exchange.

Adsorption and Desorption of Lead(II) from Aqueous Solution by Anaerobic Granular Sludge

CHEN Xiao TANG Yan-kui TONG Zhang-fa WEI Xing-ren LIANG Da-wen

. 2009, 9(3): 492-497.

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Anaerobic granular sludge is used to remove Pb2+ from aqueous solution. The results show that pH, sludge content, initial Pb2+ concentration in aqueous solution and contact time are the main factors affecting the adsorption of Pb2+. It is found that adsorption capacity 121.1 mg/g and adsorption rate 99.5% are achieved when initial Pb2+ concentration is 100 mg/L, pH 4~5 and sludge content 4 g/L, adsorption equilibrium is reached in 60 min. The viable sludge shows higher adsorption capability compared to the nonviable sludge. The adsorption process fits to the Lagergren kinetics equation. Adsorption of Pb2+ on the anaerobic granular sludge follows Lagergren kinetics expression and the experimental data are correlated reasonably well by Langmuir and Freundlich isotherm models. Using 0.1 mol/L HNO3 as desorption reagent, the desorption rate is 93.11% after three times of desorption processing.

Flotation Desulfurization of High-sulfui Bauxite with Butyl Xanthate as Collector

WANG Xiao-min ZHANG Ting-an LU Guo-zhi BAO Li JIANG Xiao-li

. 2009, 9(3): 498-502.

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The desulfurization of high-sulfur diasporic bauxite from China with flotation process and butyl xanthate as collector was studied, and the effects of flotation time, pulp density, pH value and particle size of ores on the desulfurization rate were examined. The results indicated that the sulfur in bauxite was successfully decreased through flotation. The sulfur content was lowed to 0.41% under the conditions of pH value at 10, the dose of flotation agent butyl xanthate 0.16 kg/t, frother 20 g/t, flotation time 15 min, mass ratio of liquid to solid 10, the particle size of ores 0.15 mm, and the reclamation of Al2O3 was 90.83%. The kinetics of flotation desulfurization was also studied. The flotation obeyed the first order kinetic equation.

Extraction of Aluminum from Coal Fly Ash by Acid Leaching and Its Kinetics

TONG Zhi-fang LI Ying-jie ZOU Yan-fei

. 2009, 9(3): 503-507.

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The conditions of roasting activation of coal fly ash with KF as assistant and extraction of aluminum by acid leaching were studied. The effects of conditions of roasting activation and acid leaching on the leaching rate of aluminum from coal fly ash were investigated, and the leaching kinetics studied. The results show that the optimal conditions of roasting activations were obtained as: under time 1 h, mass ratio of coal fly ash to KF 20:4, and temperature 800℃; and the optimal conditions of leaching temperature 90℃, leaching time 1 h, concentration of hydrochloric acid 4 mol/L, and liquid-to-solid ratio 4 mL/g, the leaching rate of aluminum reached 92.46%. The acid leaching process of roasted coal fly ash could be modeled with the shrinking core model. The apparent reaction progression was 0.3718, and the apparent activation energy 43.49 kJ/mol. The leaching rate was controlled by chemical reaction.

An Investigation on Reduction and Magnetization of Limonite Using Biomass

WANG Yong-bin ZHU Guo-cai CHI Ru-an ZHAO Yu-na CHENG Zhuo

. 2009, 9(3): 508-513.

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The magnetic conversion of limonite from Guangxi Chongzuo and its reduction mechanism were investigated. The effects of technological conditions such as roasting temperature, roasting time, the ratio of limonite and biomass on the mineral magnetization were examined. The results from contrast experiments between the reductants of biomassto lignitic coal showed that limonite was deoxidized at the optimum temperature of 650℃ for 30 min using 15%~20% biomass as reductant, which is lower than over 100℃ by using lignitic coal as reductant. The iron ore processed by using lignitic coal and biomass was chiefly deoxidized to magnetic Fe3O4 and g-Fe2O3, it easily transformed to iron silicate at high temperatures, leading to negative effect on its magnetic separation.

Effect of Titania Content on Physicochemical Properties of Mould Flux in Titanium Stabilized Stainless Steel

HAO Zhan-quan CHEN Wei-qing Carsten Lippold MAO Hong-xiang

. 2009, 9(3): 514-519.

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Considering that the TiO2 content in molten mould slag increases markedly during casting of titanium stabilized stainless steel and other steel grades, which affects the properties of the molten mould slag, mould fluxes were prepared, and the effect of TiO2 on crystallization temperature, melting temperature, viscosity and solidification temperature was examined. The results show that for the mould flux with basicity 0.85, its crystallization temperature was decreased by addition of 4.5% TiO2, then kept constant with continuous increase of TiO2 content. But the crystallization temperature of mould flux with basicity 1 decreased firstly, then increased markedly with continuous increase of TiO2, owing to the formation of perovskite phase. With the increase of TiO2 content in the range of 0~12%, the melting temperature of slag increased, its viscosity and solidification temperature decreased.

Composition and Morphology of Magnesium Carbonate Hydrates Synthesized by the Reaction of MgSO4 with Na2CO3 in 283~363 K

SHAO Ping-ping LI Zhi-bao MI Jian-guo

. 2009, 9(3): 520-525.

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Precipitation of various forms of magnesium carbonate hydrates was investigated by the reaction of MgSO4 with Na2CO3 at the temperatures from 283 to 363 K. XRD and SEM analysis showed that the reaction temperature had great effect on the morphology of precipitate. Three morphologies, needle-like, spherical-like and sheet-like, were obtained. The needle-like nesquehonite (MgCO3×3H2O) was synthesized from 283 to 313 K. When the temperature was below 303 K, the crystals obtained exhibited a smooth surface, with the increase of reaction temperature to 313 K, the needle-like particles displayed coarse surface covered by little rod-like crystals. When the temperature was up to 323~363 K, the spherical-like crystals were obtained, and with the temperature increasing, the diameter of crystals increased. The initial concentration of MgSO4 and Na2CO3 titration speed had also significant effect on crystal morphology of nesquehonite.

Investigation on Influential Factors in Electricity Generation of Microbial Fuel Cell

YE Ye-jie SONG Tian-shun XU Yuan CHEN Ying-wen ZHU She-min SHEN Shu-bao

. 2009, 9(3): 526-530.

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The output power and resistance were evaluated to investigate the effects of pH, substrate concentration, electrode spacing and electrolyte addition on the electricity generation of direct microbial fuel cell. The results showed that output power was much affected by pH. The optimal pH value was 7.5. The output power increased with the substrate concentration. It could be improved with the decrease of resistance as the electrode spacing decreased. When electrode spacing was decreased to 2 cm, the maximum power density was 700 mW/m2, the resistance 80 W, and the coulomb efficiency 7.7%. PBS as the electrolyte was much better than NaCl on power improvement. When PBS was 100 mmol/L, the maximum power density was 922 mW/m2, the resistance 70 W, and the coulomb efficiency 11.5%.

Carbothermal Reduction Process for Production of Coarse Al-Si Alloy

WANG Yao-wu FENG Nai-xiang YOU Jing YANG Dong

. 2009, 9(3): 531-535.

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The coarse Al-Si alloy was produced in a carbon tube furnace by using bauxite tailing and soft coal as raw materials. The phases of products obtained in different temperatures and carbon additions were analyzed by X-ray diffraction. The reaction process of producing coarse Al-Si alloy was studied and the acceptable product obtained. The results show that the carborundum was gained at the lower temperature (below 1600℃) when the raw materials were deoxidized in the vacuum carbon tube furnace. When the temperature rised to 1700~1800℃, alumina began to react with carbon to form aluminum oxycarbide. When the temperature was higher than 1800℃, the silicon carbide decomposed aluminum oxycarbide into aluminum and silicon, and the aluminum and silicon reacted to form coarse Al-Si alloy. The content of Al in the coarse Al-Si alloy was more than 40%.

Reaction Kinetics and Mechanism of Photocatalytic Degradation of Gaseous Toluene

YIN Yong-quan ZHENG Yan SU Yuan-cheng CUI Quan CUI Zhao-jie

. 2009, 9(3): 536-540.

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Chemical kinetics and intermediates in photocatalytic degradation of gaseous toluene were investigated under UV irradiation with TiO2. According to the intermediates analyzed by GC/MS, possible mechanism for photocatalytic degradation of gaseous toluene was proposed. The result showed that the degradation of toluene followed the first-order chemical kinetics. With the increase of initial toluene concentration, the reaction rate of photocatalytic degradation of toluene increased and the reaction rate decreased. The main intermediates of photocatalytic degradation were hexane and benzene. Toluene could be converted into benzene and methyl by demethylation with UV irradiation and TiO2. Methyl reacted with 3-penta-eneyne produced by dissociation of toluene into 2,4-hexadiene, which could produce hexane by hydrogenation.

Equilibrium Conditions of Hydrate Formation in the Systems of CO2-N2-TBAB and CO2-N2-THF

LU Tao ZHANG Yu LI Xiao-sen CHEN Zhao-yang YAN Ke-feng

. 2009, 9(3): 541-544.

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Equilibrium conditions of hydrate formation for the gas mixture of CO2 and N2 with TBAB (tetra-n-butyl ammonium bromide C16H36NBr) and THF (tetrahydrofuran) respectively were determined by employing the pressure search method. The data showed that TBAB and THF could reduce the formation pressure of gas hydrate as the additives. The experiments were carried out in the pressure range of 0.69~14.55 MPa and the temperature range of 275.75~288.15 K. The equilibrium pressures of CO2-N2-TBAB and CO2-N2-THF systems were lower than those of CO2-N2 hydrate at the same temperature. The equilibrium hydrate formation pressure of CO2-N2-TBAB system was lower than that of CO2-N2-THF at the certain temperature with the same low concentration of TBAB and THF. With 2.90%(mol) of the above additives, the equilibrium formation pressure of two systems did not have significant difference.

Simulation for Polygeneration Systems of FT Synfuels-Power Based on Different Gasification Processes

YU Ge-wen XU Yuan-yuan HAO Xu LI Yong-wang

. 2009, 9(3): 545-551.

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Polygeneration systems of FT synfuels-power based on Shell, GSP and Texaco gasification are designed and simulated. The characters of systems are also assessed. The results show that under the condition of 1000 t/h designed rate of coal feedstock, the yields of synfuels, diesel, naphtha and LPG, are 318.56, 318.42 and 285.79 t/h, respectively. However, the electricity generation does not meet the needs of systems because of 96% of CO conversion rate for FT synthesis. The generated electricity is equivalent to recovery of 2% of coal thermal value. 47.65% of the highest system thermal efficiency comes from the polygeneration based on the Shell gasification. The lowest system thermal efficiency, resulting from the polygeneration based on the Texaco gasification, has decreased 6.5% compared with the former. The proportion of carbon capture to the total carbon entering the systems is 58.69%, 58.65% and 59.55%, respectively.

Enzymatic Synthesis of High Purity Triglyceride of EPA and DHA

CHEN Xiao-e FANG Xu-bo CHEN Jie QUAN Wen-qin YU Hui

. 2009, 9(3): 552-557.

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Enzymatic synthesis of triglyceride directly from glycerol with EPA or DHA was studied by the lipase, respectively. The reaction medium, temperature, amount of lipase, molar ratio of glycerol to EPA, addition time of molecular sieves, and reaction time were examined predominantly. The optimal reaction mixture and conditions were: 6 mL hexane, molar ratio of glycerol/EPA or glycerol/DHA 1:3 (based on 0.4 mmol glycerol), 100 mg of Novozym 435 lipase, 40℃, agitation speed 150 r/min, and 1 g molecular sieve added after 24 h reaction time. After 48 h of reaction under these conditions, the yields of tri-EPA and tri-DHA were up to 88.64% and 88.07%, respectively. Meanwhile the degrees of EPA and DHA esterification were 95.0% and 94.5%. The products were identified as tri-EPA and tri-DHA.

Preparation of 2-Chlorotritylchloride Resin and Its Application in Solid Phase Peptide Synthesis

LI Peng; LIANG Hong; ZHANG Jing; SU Zhi-guo

. 2009, 9(3): 558-562.

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2-Chlorobenzophenone and phosphorus pentachloride were heated to 130~140℃ to obtain 1-chloro-2- [dichloro(phenyl)methyl]benzene (DCPB) as a precursor to the trityl group. Via Friedel-Crafts acylation, DCPB was loaded onto 1.5% DVB-crosslinked polystyrene resin particles with the diameters less than 30 mm. After quenching and washing, 2-chlorotritylalcohol (2-CTA) resin was obtained. The resulting 2-CTA resin was chlorinated by thionyl chloride to obtain 2-CTC resin. The three-step method was operated in moderate condition, and did not require any organometallic reagents. The prepared 2-CTC resin possessed superior properties in initial amino acid loading, swelling and synthesis of peptide sequences, compared with commercial 2-CTC resin. A difficulty sequence, fragment 65-74 of acyl carrier protein (ACP 65-74), was obtained in 72% yield and 76.5% purity.

Effective Expression of Porcine Interferon-a with On-line Multi-variable Monitoring

JIN Hu GAO Min-jie XU Jun DUAN Zuo-ying LIU Li-ming LI Zhen SHI zhong-ping

. 2009, 9(3): 563-567.

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Expression of porcine interferon-a (pIFN-a) under high density recombinant Pichia pastoris cultivation was conducted in a 5 L batch-scaled bioreactor. The results indicated that a high and stable oxygen uptake rate (OUR) during induction phase was the most important factor in achievement of effective pIFN-a production. On-line measurements of multi-variables would help to interpret the reasons for the formation of high and stable OUR. The high and stable OUR [200~280 mmol/(L×h)] could be realized by adjusting specific growth rate with a proper substrate feeding strategy during transient phase, followed by controlling methanol concentration at a moderate level (around 10 g/L) during the induction phase. Under high and stable OUR condition, the highest pIFN-a antiviral activity reached 6.6×106 IU/mL, which was about 10~300 folds of those obtained under lower OUR in the same bioreactor and the shaking flask experiments.

Electrodeposition of Nickel Foil under Super-gravity Field and Its Mechanical Properties

WANG Ming-yong WANG Zhi; LIU Ting GUO Zhan-cheng;

. 2009, 9(3): 568-573.

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The nickel deposition under super-gravity field was carried out and the effect of super-gravity field on current efficiency, cell voltage and specific energy were studied. The nickel foil prepared was characterized by SEM and XRD, and the effect of super-gravity field on mechanical properties of nickel foil was also investigated. The results indicated that the current efficiency and growth rate of nickel deposition were affected markedly by super-gravity field. With the increase of gravity coefficient, G, and current density, the crystal grains diminished. The tensile strength of nickel foil increased from 933 MPa under normal gravity condition to 1190 MPa under G value of 443, and the hardness increased also from 224 to 375 Hv. Under G value of 111, with the increase of current density from 0.1 to 0.4 A/cm2, both tensile strength and hardness of nickel foil increased from 1054 MPa and 285 Hv to 1121 MPa and 331 Hv, respectively.

Synthesis and Characterization of Poly(arylacetylene) Resins Containing Methylsilylene Groups

ZHANG Ling-ling GAO Fei ZHOU Wei ZHANG Jian HUANG Fa-rong DU Lei

. 2009, 9(3): 574-579.

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A series of poly(arylacetylene) resins containing methylsilylene groups (PSA-H) were synthesized by the condensation reaction between organomagnesium reagents and dichloromethylsilane. The structures of resins were characterized. The curing behavior of PSA-H resins was traced by DSC and thermal stability of the cured resins by TGA. The results showed that the resins were easily processed and cured at temperature lower than 200℃. The cured PSA-H resins possessed low dielectric constant (2.57 F/m), low dielectric loss (tand 0.001) and excellent thermal stabiliy. Td5 (temperature at 5% weight loss) of the cured resins ranged from 675℃ to 703℃, and the char yields of cured resins at 1000℃ were 90.9%~91.4% under nitrogen. After the cured resins were sintered, b-SiC-containing ceramic was obtained.

Chemical Deposition of NiO on Carbon Fibers

HUA Zhong-sheng YAO Guang-chun CAO Zhuo-kun WANG Lei MA Jia LIANG Li-si

. 2009, 9(3): 580-585.

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NiO was deposited on carbon fibers by homogeneous precipitation method. The influences of precipitation agents, dehydration method, precipitator concentration, addition speed of precipitator and deposition time on depositing were examined. NiO coating was characterized by SEM and XRD. Proper process conditions of NiO depositing on carbon fibers were obtained as follows: urea as the precipitator, Ni(OH)2 dehydrated by slow heating method, the precipitator concentration at 0.20 mol/L, addition speed of precipitator at 2 mL/min, and reaction time for 120 min. The NiO coating deposited under these conditions possessed uniform thickness without abscissions. The results of oxidation resistance test indicated that the oxidation resistance of carbon fibers was improved obviously after deposition of NiO coating.

Preparation of Activated Carbon by Vacuum Pyrolysis

YANG Juan QIU Ke-qiang WU Fei GU Li DUAN Hao

. 2009, 9(3): 586-591.

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Activated carbon was prepared from Chinese fir sawdust by chemical activation using zinc chloride under vacuum condition. The micropore structure, adsorption properties and surface morphology of activated carbon obtained under atmosphere and vacuum were investigated. The effects of system pressure, pyrolysis temperature and holding time on the characteristics of activated carbon were studied. The results show that the activated carbon prepared under vacuum had good adsorption properties, which are significantly better than those of activated carbon obtained under atmosphere. The adsorption values of iodine and methylene blue with activated carbon were 1030.43 and 343.92 mg/g, respectively, which was obtained under the conditions of system pressure of 10.5 kPa, heating rate of 5℃/min, pyrolysis temperature of 450℃ and holding time of 60 min.

Growth and Corrosion Characteristics of Plasma Electrolytic Oxidation Ceramic Films Formed on AZ31 Magnesium Alloy

WANG Li CHEN Li YAN Zong-cheng WANG Hong-lin PENG Jia-zhi

. 2009, 9(3): 592-597.

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The growth characteristics of oxide ceramic films formed on AZ31 magnesium alloy with plasma electrolytic oxidation (PEO) technique in alkaline silicate solution were investigated. The composition, structure and morphology of the coatings were detected by energy dispersive X-ray spectroscope and scanning electron microscope. The amount of dissolved magnesium in the electrolytes during PEO process was measured by atomic absorption spectrometry. The results indicated that the growth process of PEO films had three stages when applied with constant voltage mode. In the first stage, the growth rate of PEO films was low, and concentrations of elements O, Mg and Si varied slightly. After sparking occurred (the second stage), the PEO films showed higher growth rate due to the high transfer rate of ions and electrons, and the existence of plasma reactions. When the growth rate tended to maintain stable with time, the third stage happened. PEO films exhibited different uniform and pitting-corrosion characteristics in different reaction stages. The films formed at 300 V for 30 min performed best corrosion resistance and the phase of ceramic films was mainly composed of MgSiO3 and forsterite Mg2SiO4.

Synthesis and Performance of Degradable PEA-based Polyurethane

WANG Wei WANG Ming-hui; HUANG Xue-qing;

. 2009, 9(3): 598-602.

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A linear polyether amine (PEA) was synthesized by ring-opening polymerization using ethylene diamine, 2-chloroethanol and epoxy chloropropane. PEA was then cross-linked with diisocyanates to produce crosslinkable polymers, P1A, P1, P1B and P2. The synthesized crosslinkable polyurethanes were characterized by IR and 1H-NMR spectra, and their thermal stabilities and degradabilities were investigated by TG and DSC. Their biodegradabilities were studied in PBS aqueous buffer (pH 7.42) in the presence of papain. The results showed that the thermal degradation of polymers mainly consisted of two stages: the first weight loss should be due to the break of amide bond in the polymers, during which the temperatures at the maximum weight loss rate for P1A, P1, P1B and P2 were 337.3, 367.6, 372.7 and 367.4℃ respectively; the second weight loss should be due to the break of main chain of PEA, the temperatures at the maximum weight loss rate for P1A, P1, P1B and P2 were 440.5, 422.5, 444.9 and 482.7℃ respectively. The weight loss for P1 was over 40% in aqueous buffer in the presence of papain after 60 d. The biodegradation rates of polymers decreased when the quantities of cross-linking agents increased.

Properties of UV Curable Epoxy Acrylate-Alumina Nanoparticles Composite Coating

GAO Peng XUE Xiang-xin

. 2009, 9(3): 603-607.

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UV curable epoxy acrylate-alumina nanocomposite coating was prepared. Its hardness, adhesion, corrosion resistance and thermal stability were characterized. The influences of nano-alumina on properties of coating were examined. The results show that the hardness and adhesion of coating were enhanced with increasing the amount of nano-alumina. When the amount was 2%, its adhesion would reach 1 grade. When the amount was 3%, pencil rigidity of coating would reach 6H. However, further increasing the amount of nano-alumina, its hardness and adhesion were decreased. TGA and EIS analysis results revealed that the addition of unmodified nano-alumina could improve thermal stability of the coating, but militated against corrosion resistance.

Synthesis of Molecularly Imprinted Polymer for Rifampicin and Its Adsorption

ZHANG Cheng-li ZHOU Yan-mei LEI Jian-du MA Tong-sen MA Guang-hui SU Zhi-guo

. 2009, 9(3): 608-612.

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Molecularly imprinted polymer was synthesized with Rifampicin (RFP) as template molecule, methacrylic acid as functional monomers and ethylene dimethacrylate as crosslinker. The polymer was investigated in equilibrium binding experiment and Scatchard analysis to evaluate the binding characteristics and recognition mechanism of RFP molecular imprinted polymer in aqueous solution. Scatchard analysis showed that two classes of binding sites were produced in the polymer matrix under the studied concentration. Their dissociation constant (Kd) and apparent maximum binding capacity (Qmax) were Kd1=31.5 mg/mL, Qmax1=23.34 mg/g for high affinity binding sites and Kd2=9.22 mg/mL, Qmax2=12.86 mg/g for low affinity binding sites. The binding experiments of different substrates showed that the imprinted polymers possessed tailor-made recognition sides for RFP.

Preparation and Characterization of Iron-based High-temperature Water-gas Shift Catalysts with Ball Milling Method

LI Qiang FU Wei LI Qian ZHOU Guo-zhi LU Xiong-gang ZHEN Qiang

. 2009, 9(3): 613-617.

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The high-energy ball milling method was applied to prepare traditional iron-chromium-based CO high-temperature water gas shift reaction (WGSR) catalysts. The effects of milling time and K2O promoter on the catalytic activity of catalysts were investigated. The structure and morphology of catalysts were characterized by XRD, BET, and SEM, and the catalyst reducibility was measured by TPR. The results showed that the catalytic activity of catalysts without any treatment increased from 65.17% to 74.78% with the milling time increasing from 5 h to 15 h. In addition, the presence of K2O enhanced the catalytic activities, the catalytic activity of catalyst without any treatment increased from 65.17% to 87.02% for the catalyst milled for 5 h. After treating at 530℃ for 15 h, the CO conversion rate was still maintained at 85.11% at 450℃ for sample D, which bears comparison with the catalyst of B116.

Necessity and Technical Route of Value-added Utilization of Biomass Process Residues in Light Industry

XU Guang-wen JI Wen-feng; LIU Zhou-en; WAN Yin-hua; ZHANG Xiao-yong

. 2009, 9(3): 618-624.

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The processes of light industry based on agricultural feedstock produces biomass residues in large amount along with its production of food, drink, medicine, paper, etc. Typical examples include bagasse, lees of spirit, alcohol and vinegar, grounds of tea, coffee and Chinese herbs, and waste mycelia biomass in fermentation. These residues represent a kind of biomass resource that is concentrated already. Analyzing their physicochemical and biological properties, this article argued that the utilization of such biomass residues from light industry has to follow a systemized technical scheme in consideration of both pretreatment and conversion of the residues. The conversion of the residues should be also subject to the different compositions of the residues rich in cellulose, protein or lignin. Based on all of these concerns, a comprehensive and integrative technical route was suggested to implement the value-added utilization of them and thereby to raise the energy and resource utilization efficiency of light industry processes.

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