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Table of Content
05 September 2016, Volume 67 Issue 9
    CIESC Journal(HUAGONG XUEBAO)Vol.67 No.9 November 2016
    2016, 67(9):  0-0. 
    Abstract ( 43 )   PDF (8609KB) ( 186 )  
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    Affinity biomimetic chromatography and its applications for antibody purification
    LU Huili, LIN Dongqiang, YAO Shanjing
    2016, 67(9):  3523-3535.  doi:10.11949/j.issn.0438-1157.20160203
    Abstract ( 151 )   PDF (1069KB) ( 444 )  
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    Affinity biomimetic chromatography is a novel bioseparation technology for the biological active substance, particularly showing good performance for antibody purification with the advantages of low cost, stable ligand structure, high specificity and so on. The critical point of affinity biomimetic chromatography is the specially-designed biomimetic ligand. The biomimetic ligands used currently include chemical synthetic ligand and short peptide ligand, which are normally obtained by rational design and screening. For a particular target protein, instead of selecting the ligand randomly, it is necessary to build a reasonable ligand library by rational designing method and screen the suitable mimetic ligand by high-throughput screening technology. According to the recent advances in affinity biomimetic chromatography, the designing and screening of ligands used for affinity mimetic chromatography and the applications in antibody purification are reviewed in the present article.

    An efficient ammonia-water power cycle in low temperature waste heat application
    CHEN Xin, WANG Ruzhu
    2016, 67(9):  3536-3544.  doi:10.11949/j.issn.0438-1157.20160275
    Abstract ( 214 )   PDF (700KB) ( 338 )  
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    An improved ammonia-power cycle activated by low temperature waste heat is operated under three pressure stages,which consists of two turbines. Since there exists many degrees of freedom for ammonia-water power cycle and they are coupled, once the waste heat and condensation temperature are fixed, the selection range of degrees of freedom like three pressure levels and ammonia mass fraction are confined by the cycle constraints. A graphic aid is proposed to select the optimum cycle with various pairs of waste heat temperature and turbine inlet pressure under fixed condensation temperature. For the typical working condition like waste heat and condensation temperature of 190℃ and 30℃, the optimization results shows that the thermal efficiency of 21.6% is obtained and the corresponding second law efficiency is 62%. The thermal efficiency is increased by around 8% when the temperature of waste heat is from 130℃ to 190℃ under a fixed turbine inlet pressure(3500 kPa). The improved cycle increases the performance compared with Rankine cycle and ORC cycle in low temperature waste heat application (>150℃).

    Liquid-liquid equilibria for ternary systems polyoxymethylene dimethyl ethers+water+n-hexane
    ZHUANG Zhihai, ZHANG Jianqiang, LIU Dianhua
    2016, 67(9):  3545-3551.  doi:10.11949/j.issn.0438-1157.20160391
    Abstract ( 206 )   PDF (593KB) ( 219 )  
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    Polyoxymethylene dimethyl ethers (PODEn) are promising diesel additive which can be synthesized from aqueous formaldehyde solutions and methanol. Formaldehyde+methanol has been found as an economical and feasible way for the production of PODEn due to the cheap raw materials. In this study the extraction process is chosen to obtain PODEn from aqueous solution. A reliable thermodynamic model for a good system description is important for extraction equipment modeling, development and design. Liquid-liquid equilibria(LLE) data are valuable in studies of the applicability of thermodynamic model. In this work, LLE was analytically determined at 293.15 K for the following four systems:(PODE1+water+n-hexane), (PODE2+water+n-hexane), (PODE3+water+n-hexane) and (PODE4+water+n-hexane), respectively. Based on high selectivity of PODE1-4 over water and the PODEn mass fraction in the organic phase was much larger than that in aqueous phase, it was found that washing with n-hexane was an effective way of extracting PODEn from the aqueous phase without losing any significant amount of PODEn to the extract phase. The isothermal experimental data were shown a good linear fit in Hand plots with R2 being approximately unity. The well-known NRTL and UNIQUAC thermodynamic models were applied to correlate the experimental data, and the results of root mean square deviation calculation (RMSD) and ternary phase diagram analysis indicated that NRTL and UNIQUAC models all shown good predictive capabilities.

    Size of departing condensate droplets from radiant cooling ceiling
    TANG Haida, ZHANG Tao, LIU Xiaohua, JIANG Yi
    2016, 67(9):  3552-3558.  doi:10.11949/j.issn.0438-1157.20160292
    Abstract ( 128 )   PDF (930KB) ( 212 )  
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    The size of condensate droplets departing from horizontal superhydrophobic copper surfaces and conventional aluminum alloy surfaces was studied experimentally and theoretically. During the whole condensation experiment, the dew formation and departure underneath the sample surfaces were imaged by CCD. It was found that the radius of the condensate droplets of the coalescence-induced jumping condensate departed from the superhydrophobic surface was below 300 μm. The coalesced droplets merged by micro-droplets with a radius ratio ranging from 1.0 to 1.5 were subject to self-removal from the superhydrophobic surface. This was because the driving force of the released surface energy after droplet coalescence became dominant compared to the resistance of the work of adhesion and viscous dissipation with the decrease of the radius ratio. In addition, the radii of the gravity-induced falling droplet from conventional aluminum alloy surfaces were ranged from 2.0 mm to 6.0 mm, and limited by the advancing and receding contact angles. Therefore, these results revealed that the superhydrophobic surface can significantly decrease the size of droplets departing from radiant ceiling panels and reduce condensation risks of radiant cooling ceiling systems.

    Saturated pool boiling from downward facing structured surfaces with grooves
    ZHONG Dawen, MENG Ji'an, LI Zhixin
    2016, 67(9):  3559-3565.  doi:10.11949/j.issn.0438-1157.20160015
    Abstract ( 68 )   PDF (10977KB) ( 168 )  
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    In-vessel retention is a key severe accident management strategy now widely adopted by some nuclear power plants. The saturated pool boiling heat transfer coefficients and critical heat flux (CHF) were measured from downward facing structured surface with grooves in deionized water to enhance the CHF. The orientations were 5°, 30°, 45°, 60° and 90° (vertical). The results showed that the nucleate boiling heat transfer coefficients and the local CHF for structured surface with grooves were consistently higher than those for plain surface. Compared with plain surface, the CHF increase could reach 65%-90% for structured surface. The vapor blanket and wavy vapor layer bubble structures with different CHF trigger mechanisms on the downward facing surface at high heat fluxes were observed on structured surface. The enhancement of the local CHF and the nucleate boiling heat transfer coefficients was mainly due to the significantly increase of heat transfer area and the grooves that effectively improve surface wettability.

    Comparison of drying performance of compressed air drying system using different pressurized liquid desiccants
    SHAO Bin, YIN Yonggao, ZHANG Xiaosong
    2016, 67(9):  3566-3573.  doi:10.11949/j.issn.0438-1157.20151987
    Abstract ( 98 )   PDF (538KB) ( 239 )  
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    To compare the difference of drying performance and mass transfer ability between LiCl and LiBr solution used in the compressed air drying system, the experiments were performed using LiCl and LiBr solution, respectively. The drying performance was compared on the basis of the same solution temperature and surface vapor pressure. The mass transfer coefficients between compressed air and LiCl liquid desiccant were calculated based on the heat and mass transfer model. The results indicated that the humidity ratio of air using LiCl liquid desiccant was lower and the moisture removal rate was higher than LiBr in the same experimental operating conditions, while the mass transfer coefficients between compressed air and LiCl liquid desiccant were higher than LiBr. It was concluded that using LiCl liquid desiccant can obtain better drying performance and mass transfer ability in compressed air drying system.

    Characteristics of Marangoni dynamic condensation modes for water-ethanol mixture vapors on horizontal surface
    CHEN Nana, WANG Jinshi, LI Yong, XIA Kai, YAN Junjie
    2016, 67(9):  3574-3582.  doi:10.11949/j.issn.0438-1157.20160031
    Abstract ( 118 )   PDF (3699KB) ( 128 )  
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    An experimental system was designed and built for condensation on a horizontal surface. Using the high-speed camera, the characteristics of Marangoni dynamic condensation modes for water-ethanol mixture vapors was investigated. The influence of initial vapor-to-surface temperature, ethanol vapor concentration and vapor velocity on the condensation modes was obtained. Using the method of edge detection to process the condensation pictures, the variation of maximum droplet radius, which was considered as an important parameter for quantitatively expressing Marangoni condensation modes, was obtained. The results showed that the condensation modes altered dramatically as condensation started. Then, the generation, merging and growing process of droplets could be observed until the condensation modes nearly kept constant. The order of magnitudes for the droplets growth time was about 10 s. On the beginning of condensation, when the initial vapor-to-surface temperature was high, filmwise and dropwise condensations were all on the surface. The number of droplets increased with the decrease of initial vapor-to-surface temperature. With the initial vapor-to-surface temperature kept decreasing, the surface would be covered by many small droplets. When the initial vapor-to-surface temperature decreased and ethanol vapor concentration increased, the droplets growth time would be longer, the droplets would grow slower. By contrast, the growth of droplets was slightly affected by vapor velocity. The maximum droplet radius increased during the condensation process and it would increase from 2 mm to more than 10 mm. At the same condensation time, the maximum droplet radius increased with the increase of initial vapor-to-surface temperature and decrease of ethanol vapor concentration.

    Effect of rapid water-cooling process on desulfurization performance of CFB bottom ash
    LI Hao, CHEN Wufeng, WANG Chang'an, CHE Defu
    2016, 67(9):  3583-3589.  doi:10.11949/j.issn.0438-1157.20160227
    Abstract ( 72 )   PDF (861KB) ( 115 )  
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    A rapid water-cooling process to desulfurize high temperature CFB bottom ash was designed for the improvement of poor ash utilization. Apparatus and methods for bench-scale rapid water-cooling and desulfurizing study were established and CFB ashes with and without treatment were characterized for f-CaO content, microscopic structure, and desulfurization efficiency. Through theoretical analysis, a hypothesis, that rapid water-cooling could facilitate destroying shell of CaSO4 particles, was proposed and validated experimentally. Results of SEM/EDX and TGA analyses on treated and non-treated ashes showed that calcium on particle surface increased evidently and the calcium recycling rate could increase about 30% post water-cooling treatment. The desulfurization efficiency enhanced continuously with increasing temperature of CFB bottom ash before rapid water-cooling. When hot CFB ash entered into water, ash particles could burst and destroy CaSO4 shell due to strong thermal stress across particle surface. Since higher temperature of CFB ash prior to water-cooling would result in stronger thermal stress, CaSO4 shell were destroyed more easily and desulfurization efficiency became higher. Thus, the rapid water-cooling process would be a new method for regeneration and reuse of CFB ash by improving desulfurization efficiency, which certainly provided practical guidance for engineering applications.

    Flame stability and structure of opposed methane/air jet in coaxial tubes
    HUANG Jinghuai, LI Junwei, CHEN Xinjian, WEI Zhijun, WANG Ningfei
    2016, 67(9):  3590-3597.  doi:10.11949/j.issn.0438-1157.20151926
    Abstract ( 118 )   PDF (1759KB) ( 183 )  
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    By using the skeletal reaction mechanism, the combustion in an opposed methane jet in coaxial narrow air stream tubes is studied. The temperature, species distribution, heat flux, flame stretch rate and flame curvature are calculated. When the fuel flow rate (QF)=120 ml·min-1, with increasing QA, the flame changes from flat-disk shape to curved one and covers the inner tube exit, and the flame is forced to move toward the exit of inner pipe. The flame is compressed and the distributions of temperature and species are compact. When equivalence ratio (ER)>1.00, with increasing QA, the peak temperature and the flame length along the flame surface rise and reach the maximum, while when ER≤1.00, the peak temperature and the flame length decrease. The after burning gas preheats the inlet methane through the inner pipe and the total heat flux is influenced by the flame temperature and gas flow. With the increase of QA, the heat flux is much stronger and the preheating increases, reaching the maximum when QA=2450 ml·min-1. When QA>2450 ml·min-1, the preheating goes down. When ER>1.00, the stretch rate of flame κ is small and changes slowly at the beginning, and then it rises sharply along the flame surface but finally it is no more than 65 s-1. When ER≤1.00, along the flame surface, κ increases first and then decreases, and finally become negative with the minimum value of -262 s-1. The increase of QA makes κ change seriously. The maximum of κ is 638 s-1.

    Characteristics of ash deposition on a novel heat transfer surface
    LI Jinbo, WANG Peili, CHENG Lin
    2016, 67(9):  3598-3606.  doi:10.11949/j.issn.0438-1157.20160232
    Abstract ( 156 )   PDF (9729KB) ( 446 )  
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    A novel structure with rhombus heat transfer surface used in the waste heat boiler was researched. Numerical simulation and experimental investigation were conducted to obtain characteristics of ash distribution and deposition. A deposition model was built to predict the stick, rebound and shedding of an ash particle, and the simulation results were compared with traditional staggered and aligned tubes arrangement. The results indicated that the rhombic surface showed obvious advantages in the heat transfer and ash deposition. The deposits were mainly concentrated on the upper left side. Particle deposited on windward side due to the inertial impaction and on leeward side because of pipe wall vortex. The deposition amount of windward side was higher than that of the leeward side. The deposition increased firstly and then decreased with the increase of the particle size under the same velocity. When the gas velocity was 3 m·s-1 and particle diameter was 5 μm, the ash particle deposition rate was up to 9.49%. For particles of the same size, the deposition rate decreased gradually with increasing velocity.

    Ejection profile and kinetics of droplets spreading on superhydrophilic porous surfaces
    YANG Wolong, XU Jinliang, JI Xianbing
    2016, 67(9):  3607-3615.  doi:10.11949/j.issn.0438-1157.20160018
    Abstract ( 111 )   PDF (1583KB) ( 310 )  
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    Exploring droplet impact onto solid surface is important to explain phenomena occurred both in nature and engineering applications. Compared to non-permeable surfaces, fewer studies have been conducted specifically on droplet impact onto permeable surfaces. Four different types of superhydrophilic micro/nano porous structures were prepared and used to investigate ejection behavior and kinetics of droplets at low impact velocity under the influence of structural parameters, including dimensional characteristics, porosity, and surface roughness of porous media. An inertial regime was identified during early stage spreading of droplets on porous surface, and the normalized spreading diameter obeyed the power-law function. The porosity change of nanoporous media had no significant effect on the power law, but the porosity increase of microporous media led to a decrease in values of both C and α. The increase in C value was also observed with increasing surface roughness. Two novel models of droplet ejection were discovered as the first-stage pinch-off and the second-stage pinch-off. Being a competitive process between the horizontal and vertical rates of collapse, the horizontal collapse could induce pinch-off when the vertical collapse was sufficiently delayed by the capillary waves. Fast inertial spreading velocity and long inertial time resulted in the first-stage pinch-off occurred in nanoporous media.The increased vertical collapse rate of droplets and the decreased inertial time by improvement of permeability were responsible for the second-stage pinch-off occurred in microporous media.

    Influence of vortex on heat transfer enhancement in triangular grooved channel by pulsating flow
    HUANG Qi, WANG Xunting, YANG Zhichao, ZHONG Yingjie
    2016, 67(9):  3616-3624.  doi:10.11949/j.issn.0438-1157.20160231
    Abstract ( 121 )   PDF (15270KB) ( 139 )  
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    In this paper, heat transfer enhancement in the triangular grooved channel by a laminar pulsating flow is studied. The influence of several main parameters on heat transfer enhancement is analyzed. The parameters are Reynolds number, Strouhal number and pulsation amplitude. The experimental results show that the enhancement of heat transfer rate increases with the Reynolds number and pulsation amplitude, and there exists an optimal Strouhal number for the greatest enhancement of heat transfer in the triangular grooved channel. To analyze the correlation between the pulsating flow behaviors and the heat transfer enhancement characteristics, the PIV investigation is performed. The PIV results show that the heat transfer enhancement results from the strong mixing caused by the repeating sequence of vortex generation, growth, expansion and ejection from the groove to the main stream by the pulsating flow. The repeating sequence of vortex variation changes the flow pattern, which leads to destroy the boundary layer and make the mixing speed faster in the different zones. What's more, the numerical research has been conducted to investigate the synergy of the temperature, velocity and pressure fields on the laminar pulsating flow in a triangular grooved channel. The numerical results indicate that an increase of the intersection angle between velocity and pressure gradient improves the synergy between the velocity and pressure fields with an equal heat transfer enhancement, resulting in a reduction of penalty of pressure drop. Therefore, the improvement of three-field synergy is the basic mechanism for the heat transfer enhancement in the triangular grooved channel by a laminar pulsating flow.

    Application of multi-scale entropy in analyzing pressure difference signals of gas-liquid two-phase flow in rod bundled channel
    ZHOU Yunlong, YIN Hongmei, DING Huixiao
    2016, 67(9):  3625-3632.  doi:10.11949/j.issn.0438-1157.20160334
    Abstract ( 117 )   PDF (2092KB) ( 157 )  
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    Due to non-linearity of pressure difference signals of gas-liquid two-phase flow in rod bundled channel and capability of multi-scale entropy analysis in charactering complex signals, multi-scale entropy analysis was used to study time series of pressure difference signals of gas-liquid two-phase flow in the 7×7 rod bundled channel under 104 different flow conditions. Results showed that the change rate of multi-scale entropy in small scales (no more than 8) could accurately distinguish four flow regimes in the rod bundled channel whereas the trending of large scale sample entropy could disclose dynamic characteristics of each flow regime. Therefore, compared to chaotic time series analysis of R/S method, the multi-scale entropy analysis method could reveal the dynamic characteristics and also accurately distinguish four flow regimes of gas-liquid two-phase flow in the rod bundled channel.

    Effect of inclination on flow resistance characteristic in narrow rectangular channel
    TIAN Chunping, YAN Changqi, WANG Jianjun, XIONG Kun
    2016, 67(9):  3633-3639.  doi:10.11949/j.issn.0438-1157.20160323
    Abstract ( 85 )   PDF (1047KB) ( 234 )  
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    Most existing studies on flow resistance characteristic focus on horizontal or vertical narrow rectangular channel, however, the inclined heated channel can be found in many heat exchanger under ocean condition. Thus, it is necessary to do some researches on it. The experiments were conducted in a narrow rectangular channel under unheated force circulation condition and heated natural circulation condition. The inclination angles ranged from -30° to 30° with 40-60 K subcooling and pressure of 0.2 MPa. It was found that the friction factors for laminar flow under unheated condition were very close to the predictions of Shah & London correlation, whereas discrepancies occured when the channel was heated. The friction factor was found to increase with the positive inclination angles, but little response to the negative inclination was found. The secondary flow driven by density differences may be the reason for differences between friction factors.

    Effect of periodic boundary conditions on heat transfer process of crude oil in floating roof storage tank
    SUN Wei, CHENG Qinglin, WANG Peidi, LI Yuchun, SUN Haiying
    2016, 67(9):  3640-3650.  doi:10.11949/j.issn.0438-1157.20160361
    Abstract ( 128 )   PDF (2132KB) ( 257 )  
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    With the increase in demand for oil storage,the scale of tanks are developing towards the direction of large scale and better adaptability to extreme working conditions. The change of oil temperature field inside the tank should be accurately grasped, which is of great significance to guarantee safe and economical operation of oil depot. Aiming at the periodic change conditions of tank ambient conditions such as solar radiation, atmospheric temperature and etc., a theoretical model of the unsteady-state heat transfer process of large double-deck floating roof tank is established by using the theory of heat transfer, and the forward difference equations of boundary point are obtained by model region discretion. On basis of determining the physical properties of crude oil in the storage tank, heat transfer coefficient of the tank as well as the heat flux density of boundary, the numerical stimulation method of temperature field in the tank can be studied. The analysis and application of a 10×104 m3 floating roof storage tank in Daqing has shown that the temperature drop rate increases with the decrease of the solar radiation intensity and the atmospheric temperature. The effect of solar radiation on temperature drop rate of tank shell is small, which increases with the decrease of atmospheric temperature. The tank bottom is approximate to adiabatic state and the effect of the external environment on temperature drop rate is small. The results can provide theoretical support to optimize the storage process design and manufacturing management of large floating roof tanks.

    Temperature characteristics of radial eccentric gravity heat pipe
    WANG Wei, XIA Guodong, MA Dandan, CHENG Yue
    2016, 67(9):  3651-3657.  doi:10.11949/j.issn.0438-1157.20151661
    Abstract ( 90 )   PDF (746KB) ( 210 )  
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    The temperature characteristics and their effect factors of a radial eccentric gravity heat pipe were investigated experimentally under natural convection and forced convection. For the test, a radial eccentric gravity heat pipe was fabricated with two eccentric pipes of unequal diameters that create an annular vapor space. The radial eccentric heat pipe was sealed with a high vacuum valve by which the filling ratio could be changed. The experiments were performed in the range from 70 to 100℃ and filling ratios (FR) from 15% to 60%. The temperature stability, uniformity and distributions of the outer surface of the outer pipe and the inner surface of the inner pipe were affected by various factors, such as filling ratios, the locations of the heater controller probe and the cooling capabilities of the inner pipe. The wall temperature distributions on both the outer surface of the outer pipe and the inner surface of the inner pipe were monitored and analyzed. The results indicated that the temperature stability of the inner surface of the inner pipe was about ±0.024℃ for 2 h. The maximum temperature difference was 0.142℃ over 20 cm in the central part of the measuring zone and the minimum temperature of the outer surface of the outer pipe appeared underneath the inlet of cooling air. The results also showed that the radial eccentric gravity heat pipes were very promising in the applications of temperature calibration field.

    Detecting the best electromagnetic field intensity in experiment of electromagnetic anti-fouling based on metastable zone
    WANG Jianguo, LI Bin, LIANG Yandong, YIN Zhao, CHEN Si
    2016, 67(9):  3658-3662.  doi:10.11949/j.issn.0438-1157.20160267
    Abstract ( 126 )   PDF (469KB) ( 163 )  
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    Electromagnetic field anti-fouling technology has received great attention because of its advantages of low investment, zero pollution, etc. Reasonable selection of electromagnetic parameter is one of the necessary conditions for the best result of electromagnetic anti-scaling. This research designed a set of dynamic electromagnetic experiment with electrical conductivity method. The characteristics of varying conductivity with time in the titration process under the given experimental conditions were compared, and the calcium carbonate crystallization metastable curve under different solution concentration and intensity of the electromagnetic field were obtained. Then, the influence of electromagnetic field on the induction period of calcium carbonate precipitation from the perspective of the metastable zone was analyzed. Finally, it was found that the 200 Gs was the best magnetic field intensity values of electromagnetic fields inhibiting calcium carbonate crystallization.

    Separation efficiency analysis and numerical simulation of gas-liquid cross-flow array system
    LIU Lingling, WEI Wenyun, XU Ting, YANG Yaqi, YU Hui, ZHU Jiahua
    2016, 67(9):  3663-3671.  doi:10.11949/j.issn.0438-1157.20160164
    Abstract ( 93 )   PDF (1795KB) ( 183 )  
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    A lab-scale Gas-Liquid Cross-Flow Array system (GLCA) was built up to investigate the effect of velocity, arrangement of liquid columns and particle size on separation efficiency of particles in gas by a continuous and regular liquid column array of water. These continuously falling water liquid columns were perpendicular streams to the dusty gas flow, so that particles could be captured by the water streams due to inertial, diffusion and interception mechanism. The experimental results showed that the separation efficiency decreased with increase of the specific surface area and particle size whereas the effect of velocity in the experimental range was unremarkable. Under the optimal column arrangement, a separation efficiency of 37.3%, 43.9% and 99% was achieved for particle size of 0.1, 1 and 10 μm, respectively, at an air velocity of 1 1 m·s-1 after 162 unit rows. A prediction formula was proposed for extrapolative calculation of grade efficiency of separation and expected pressure drop of a given particle size as a function of the unit number of liquid column arrays. As an example, total pressure drop was expected no more than 300 Pa for 0.4 μm particles at 95% separation efficiency. Large eddy simulation (LES) at the optimized experimental conditions yielded the numeric simulation in good agreement with the experimental data and thus verified prediction formula of separation efficiency. With this model, it is possible to predict the performance of GLCA although other driving forces would be taken into account, e.g. the thermophoretic force and the convection caused by vapor condensation and chemical reactions.

    Impact of B2O3 loading on sulfur-resistant methanation activity of MoO3/CeO2-Al2O3 catalyst
    LIU Zhen, WANG Baowei, WANG Weihan, MENG Dajun, LI Zhenhua, MA Xinbin
    2016, 67(9):  3672-3677.  doi:10.11949/j.issn.0438-1157.20160317
    Abstract ( 90 )   PDF (2763KB) ( 186 )  
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    Synthetic natural gas (SNG) production from coal is considered again due to rising prices for natural gas, the wish for less dependency from natural gas imports and the opportunity of reducing green house gases. The technical, economic and ecological feasibility of SNG with Mo-based catalysts showed water-gas shift and sulfur-resistant methanation has been studied. In this paper the impact of B2O3 loading on the MoO3/CeO2-Al2O3 catalysts for sulfur-resistant methanation was investigated. The catalysts were prepared by impregnation method and characterized by means of BET, XRD, TEM and NH3-TPD. The results showed that the sulfur-resistant methanation activity of MoO3/CeO2-Al2O3 catalysts were increased at first and then decreased as the increase of B2O3 loading. The catalyst adding 0.5% B2O3 showed the highest activity and the conversion of CO was 55%. The characterization results indicated that the addition of B2O3 had influences on the structure and surface acidity of catalysts and the dispersion of active components, which further impacted the activity of catalysts. High-crystallization and enhancement of strong acid quantity were not beneficial to the sulfur-resistant methanation, while the high dispersion of active components was favorable to the improvement of the catalyst activity.

    Surface structure and activity of iron molybdate catalyst for methanol oxidation to formaldehyde
    ZHANG Shuai, ZHANG Yike, HU Rlckt, ZHEN Bin, HAN Minghan
    2016, 67(9):  3678-3683.  doi:10.11949/j.issn.0438-1157.20160132
    Abstract ( 154 )   PDF (4867KB) ( 382 )  
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    Iron-molybdenum catalysts with the same atomic ratio of Mo/Fe for methanol oxidation to formaldehyde were prepared by co-precipitation method under varied rates of stirring. The catalysts were characterized by SEM, XRD and Raman spectrum and the catalytic activity and selectivity evaluated in a fixed-bed reactor.It showed that with an increase of stirring speed, the specific surface area of the catalysts increases and the catalytic activity enhances. The yield of formaldehyde increases from 73.8% at 600 r·min-1 to 95.7% (T=280℃) at 10000 r·min-1. The catalyst consists of plate-like MoO3 and amorphous sponge-like Fe2(MoO4)3. In addition, the catalyst consists of sheet-shaped MoO3 and particle-shaped Fe2(MoO4)3, of which the former had barely no activity, and only the combination of the former and the latter (Fe2(MoO4)3) does show the catalytic activity.

    Effect of Ag addition on performance of Au/TS-1-B catalyst in gas phase propylene epoxidation
    YANG Jia, ZHANG Zhihua, FENG Xiang, DUAN Xuezhi, ZHOU Jinghong, ZHOU Xinggui
    2016, 67(9):  3684-3691.  doi:10.11949/j.issn.0438-1157.20160281
    Abstract ( 76 )   PDF (3469KB) ( 348 )  
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    Propylene epoxide (PO), as a versatile bulk chemical intermediate, is widely used in the production of a variety of derivatives. Direct propene epoxidation with molecular H2 and O2 to synthesize PO is a greener, simpler and more sustainable route compared with traditional chlorohydrin and several organic hydroperoxide processes. In this study the uncalcined titanium silicate-1 with blocked micropores (TS-1-B) was used to support Au nanoparticles (Au/TS-1-B) for direct propylene epoxidation with hydrogen and oxygen. Au-Ag/TS-1-B was prepared by sequential deposition-precipitation method followed by in-situ reduction to improve the performance of the catalyst. After introducing Ag, the catalytic stability was improved. UV-vis DRS analysis showed the existence of Ag-Au bimetallic particles. It was observed from HRTEM results that the metal particle size was much smaller on Au-Ag/TS-1-B than on Au/TS-1-B and the particle size of the metal particles on both catalysts did not change during the reaction process. Moreover, pyrolysis GC-MS results showed less coke was formed on Au-Ag/TS-1-B and coke could be reduced by regeneration. All these accounted for the significantly improved activity and stability of Au-Ag/TS-1-B catalyst.

    Microkinetics analysis of acetylene hydrogenation over Pd/Al2O3 catalyst with different particle sizes
    PANG Hongqiang, SUI Zhijun, ZHU Yi'an, ZHOU Xinggui
    2016, 67(9):  3692-3698.  doi:10.11949/j.issn.0438-1157.20160283
    Abstract ( 144 )   PDF (4801KB) ( 412 )  
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    Pd/α-Al2O3 with different particle sizes were prepared by the incipient wetness method and characterized by BET, XRD, ICP-AES, CO chemisorption and TEM. The kinetic characteristics over these catalysts were explored following a fractional factorial designs of experiment and the experiment results were analyzed by microkinetic method. The size of three catalysts obtained was 1.6 nm, 3.4 nm and 5.5 nm, respectively, as verified by TEM and CO chemisorption results. After stable performance of the catalyst, the exposed surface Pd number of catalysts measured from CO chemisorption agreed well with that of Pd(111) surface calculated from Hardeveld's model. The microkinetic analysis results showed that the microkinetic model can fit the kinetic experiment results quite well on all catalysts. C2H4* and C2H3* were the most abundant surface species independent of the reaction conditions. The rate determining step was the hydrogenation of vinyl group to form ethylene according to the relationship between microkinetic information and macrokinetic characteristics.

    Modified mesoporous silica supporting platinum catalyst for synthesis of agricultural synergist
    XIE Huilin, ZHANG Weixin, ZHU Guiyou, HU Wenbin, LIAO Liewen, JIA Zhenyu, LIU Qihai
    2016, 67(9):  3699-3706.  doi:10.11949/j.issn.0438-1157.20160458
    Abstract ( 95 )   PDF (724KB) ( 183 )  
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    Pt/CS-SiO2 catalyst was prepared by impregnating platinum on chitosan modified mesoporous silica and characterized by Fourier Transform Infrared Spectroscopy (FTIR), nitrogen adsorption-desorption (BET), thermogravimetric analysis (TGA). Catalytic performance was evaluated in hydrosilylation of polyether and trisiloxane for synthesizing agricultural synergist. The experimental results showed that Pt was successfully incorporated on modified mesoporous silica at content of 0.85%. The new catalyst had excellent reusability, which still maintained high activity with greater than 90% of both conversion and selectivity after reused seven times. The optimal synthesis condition for agricultural synergist was a mixture of polyether and trisiloxane at a molar ratio of 1:1.1 and 105℃ for 3 h. The agricultural synergist exhibited excellent stability in neutral aqueous solution by hydrolysis assessment at various pH conditions.

    CH4 storage in nanoporous activated carbon by molecular simulation
    WU Di, WANG Shanshan, LÜ Linghong, CAO Wei, LU Xiaohua
    2016, 67(9):  3707-3719.  doi:10.11949/j.issn.0438-1157.20160274
    Abstract ( 127 )   PDF (2153KB) ( 481 )  
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    Adsorbed natural gas is considered as the most promising method for CH4 storage in the future. The key is to find suitable adsorbents to achieve good absorption/desorption performance. Methods of grand canonical Monte Carlo and equilibrium molecular dynamic simulation were adopted in this article to research the adsorption and diffusion of CH4 in nanoporous carbons. Some factors influenced the adsorption and diffusion of CH4 in nanoporous carbons including the size of graphite slice unit, different density of nanoporous carbons and the surface functionalization of nanoporous carbons were investigated, respectively. Results showed that the types and proportions of graphite slices used to generate the nanoporous carbons had little impact on CH4 adsorption. The density of nanoporous carbons had an effect on CH4 adsorption. The optimal density of pristine nanoporous carbons was about 0.50 g·cm-3 and the optimal density of modified nanoporous carbons was at around 0.72 g·cm-3. When modified with different functional groups, the CH4 adsorption capacity in the modified nanoporous carbons was in the sequence of CH3-NPC > OH-NPC > CO-NPC > COOH-NPC > NPC. For the diffusion of CH4 nanoporous carbons, nanoporous carbons with low density and COOH group had high self-diffusion coefficient.

    CFD simulation for atomic layer deposition on large scale ceramic membranes
    ZHU Ming, WANG Yong
    2016, 67(9):  3720-3729.  doi:10.11949/j.issn.0438-1157.20151660
    Abstract ( 145 )   PDF (829KB) ( 239 )  
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    Ceramic membranes are widely used in liquid filtration for their superior chemical resistance, temperature stability and mechanical robustness. Their performance can be further improved by surface modifications, such as liquid phase reactions, which are typically too complicated to control. Atomic layer deposition (ALD), a deposition technique of self-limiting gas/solid phase chemical reactions for growing atomic scale thin films, has been extremely useful for precisely regulating nanoscale pore structures, especially modification and functionalization of porous separation membranes. Most existing ALD equipment are designed for silicon wafer substrate in semiconductor industry, thus design optimization on ALD processes of both precursor flow and surface reactions are needed for application in large-scale ceramic membranes. Computerized fluid dynamics (CFD) modeling was used to investigate ALD process on 1-meter-long single-channeled ceramic membrane by considering both boundary conditions and surface chemical reactions of two precursors pulsed alternatively into the channel. The simulations fitted well with the experimental data at average difference of 1.69% and thus an ALD model for two-way alternatively pulsed rotation was proposed, which would be very helpful in equipment design and process optimization of ALD for large scale ceramic membranes.

    Development of inorganic nano particles modified sodium alginate hybrid membranes for pervaporation
    NA Shasha, LI Weixing, XING Weihong
    2016, 67(9):  3730-3737.  doi:10.11949/j.issn.0438-1157.20160111
    Abstract ( 83 )   PDF (3110KB) ( 155 )  
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    In order to improve the pervaporation performance of SA, nano-alumina, nano-zirconia and nano-titania were incorporated into SA solution, respectively. The difference of pervaporatin performance was analyzed, and the membrane that had better separation performance was selected for pervaporation (PV)-assisted esterification of acetic acid and ethanol. The effect of nano-particles content on the separation performance was investigated. The obtained membranes were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG) and differential scanning calorimetry (DSC). The thermal stability, tensile strength and permeate flux of hybrid membranes were enhanced after incorporating nano-particles into SA. When the mass ratio of nanoparticles to SA was 0.3, the methylene iodide contact angle of incorporated TiO2, ZrO2 and Al2O3 hybrid membranes increased, respectively. Meanwhile, the permeate flux increased at the same time. The hydrophilic property of SA-0.3Al2O3 membrane was the best; however, the separation performance of SA-0.3ZrO2 membrane was better. The permeate flux of SA-0.3ZrO2 membrane was 336 g·m-2·h-1 with water content 99.97% in the permeate side and separation factor 29990 when the amount of water in feed was 10% at 50℃. The conversion of esterification enhanced by pervaporation reached 93.9% in 12 h at 80℃.

    Synthesis and characterization of copolymer-grafted cation-exchangers for protein adsorption
    ZHANG Suling, YANG Wei, YU Linling, BAI Shu, SUN Yan, SHI Qinghong
    2016, 67(9):  3738-3746.  doi:10.11949/j.issn.0438-1157.20160349
    Abstract ( 120 )   PDF (833KB) ( 257 )  
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    High-capacity chromatographic packings for protein adsorption are the material prerequisite for the development of efficient protein chromatography processes. In this work, random copolymer-grafted cation-exchangers for protein adsorption were synthesized by grafting 3-sulfopropyl methacrylate and methyl methacrylate (MMA) to Sepharose Fast Flow via atom transfer radical polymerization, and lysozyme and antibody adsorption on to these cation-exchangers was investigated. In case of a given total concentration of the monomers for the grafting reaction, the pore radii of the copolymer-grafted cation-exchangers increased with an increase of MMA concentration, indicating a typical characteristic of a decreasing depth of polymer layer and gradual collapse of the random copolymers. Adsorption equilibria showed that the adsorption capacity for lysozyme was dominated by ionic capacity of the cation-exchangers whilst for antibody it was related to pore radius and corresponding the change in depth of polymer layer. With an increase in depth of polymer layer, there was stronger steric excluded interaction between antibody and polymer layer, and thus decreasing the adsorption capacity for antibody. Moreover, the results demonstrated that the adsorption capacities for proteins on random copolymer-grafted cation-exchangers were improved by optimizing the conformation of random copolymer chains.The adsorption capacities for antibody and lysozyme reached 237 and 380 mg·g-1 in the optimized random copolymer-grafted cation exchangers, respectively. The research revealed that both layer depth of copolymer and protein binding were also regulated by ionic strength in copolymer-grafted cation-exchangers.

    Kinetics of adsorptive desulfurization over alkaline-treated Beta zeolite
    PAN Xingpeng, WU Xiangying, DU Jun, QIAN Mingchao, YU Jiang
    2016, 67(9):  3747-3754.  doi:10.11949/j.issn.0438-1157.20160245
    Abstract ( 118 )   PDF (1485KB) ( 322 )  
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    When molecular size of an adsorbate is as large as the pore size of molecular sieves, the adsorbate can enter into the pore structure and thus the pore size of molecular sieves is a critical factor in determining adsorption performance. To improve adsorbate selectivity and diffusion, Beta molecular sieves were modified by alkaline treatment of NaOH solution. The treated Beta molecular sieves were characterized by analytical techniques of BET, TEM, FT-IR, XRD and NH3-TPD to investigate the alkaline treatment process on crystal structure, surface acidity and pore structure. Adsorption desulfurization showed that both adsorption quantity and adsorption rate of alkaline-treated Beta molecular sieves were improved obviously. Especially the adsorption of large-kinetic-sized dibenzothiophene reached to 5.06 mg·g-1. The kinetics of adsorbing dibenzothiophene on Beta molecular sieves was a pseudo-2nd-order adsorption process. After alkaline treatment, rate constants of both adsorption and molecular diffusion inside pores were increased significantly, which in turn improved mass transfer of diffusion inside porous structures and desulfurization efficiency of sulfur compounds.

    Effects of solid adsorption on vacuum flash water separation process with heat pipe
    GAO Wenzhong, XU Changda, LI Changsong, WANG Dong, SU Tianlong
    2016, 67(9):  3755-3761.  doi:10.11949/j.issn.0438-1157.20151909
    Abstract ( 84 )   PDF (526KB) ( 125 )  
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    The superheat is the key factor for liquid drop to keep evaporating and it determines the water separation rate of the solute/water separator. A solute/water separation device combined with high efficient heat pipe and solid adsorption technology is developed in this paper. Water separation experiment of NaCl solution with concentration of 3% is conducted and the results show that the heat pipe can rapidly transfer heat to the drop just flashed for the second boiling with high heat flux and increase the water separation rate per unit volume. During the front half part of the adsorption process, the evaporator pressure value has a significant decrease by 0.4-1 kPa than that without adsorbent bed. Namely, the boiling point of drop is reduced and superheat is increased. This provides a new method for utilizing lower grade heat source in the solute/water separation.

    Flash evaporation characteristics of ethanol solution droplets under depressurization
    HUANG Liang, ZHANG Xuelai
    2016, 67(9):  3762-3767.  doi:10.11949/j.issn.0438-1157.20160151
    Abstract ( 133 )   PDF (4642KB) ( 489 )  
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    Based on the flash evaporation theory of a liquid droplet under low pressure, a visual vacuum flash evaporation device was designed for experiment of a suspension droplet. The experiment was performed to investigate the depressurized flash evaporation characteristics of ethanol solution droplets with the mass fraction of 0, 5%, 10% and 20%, and record the nucleation crystallization process. The liquid droplet went through five morphological changes, respectively:liquid evaporation process, evaporation with bubble growth process, steady evaporation ice process, ice formation with bubble growth process and external ice and internal bubbles escape eventually burst under depressurization. The research showed that the higher the ethanol solution concentration was, the lower the droplets freezing point and the longer the droplet freezing time were. Moreover, it was also found that the ethanol solution in some concentration could increase the pressure of flash chamber when the droplets crystallized and reduced the vacuum requirements of the system.

    Treatment of produced polymer-containing wastewater at oilfield using airlift ceramic membrane filtration equipment
    SHEN Hao, ZHANG Chun, CHEN Chao, JING Wenheng, XING Weihong
    2016, 67(9):  3768-3775.  doi:10.11949/j.issn.0438-1157.20160253
    Abstract ( 97 )   PDF (776KB) ( 166 )  
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    A novel airlift ceramic membrane filtration equipment was employed to treat the produced polymer-containing wastewater at oilfield. In the process of treatment on the produced polymer-containing wastewater at oilfield by ceramic membrane filtration, the energy consumption was reduced due to the gas-liquid two phase flow in place of monophase flow of liquid. Effects of aeration pore size, aeration rate and transmembrane pressure on membrane flux were investigated. It showed that the microporous aeration promoted the more homogeneous distribution of gas inside membrane tube, hence inhibited membrane contamination and concentration polarization and the alleviated decay of membrane flux. The maximum flux was achieved under condition of 1 μm of aeration pore size, of which the membrane flux increased remarkably with an increase in aeration rate from 300 to 600 L·h-1. Moreover, the transmembrane pressure influenced the membrane flux significantly, with an optimal pressure of 0.4 MPa. The various parameters of quality of the permeated water are stable, which satisfies the requirements of the standard 5.1.1 of reusing water. The energy consumption per ton water of airlift ceramic membrane filtration equipment was also calculated.

    Influence of feed forward variables on feasible region of model predictive control
    ZHANG Jia, LUO Xionglin, XU Feng, XU Jun
    2016, 67(9):  3776-3783.  doi:10.11949/j.issn.0438-1157.20160036
    Abstract ( 70 )   PDF (574KB) ( 189 )  
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    The model predictive control is widely used in real process because of its decoupling and strong robustness. In the past studies, the effects of disturbances on model predictive control were mostly ignored. For the measurable disturbances whose dynamic rules are known, the influence of measurable disturbances on controlled variables can be predicted, and thus the measurable disturbances can be used as feed forward variables in model predictive control. The introduction of feed forward variables will affect the control performance of the system. The result solving directly under no analysis cannot reflect the actual effect of model predictive control. From the viewpoint of feasible region, this paper studies the feasible region changes caused by feed forward variables through the geometric forms. The convex space method is used to determine the size of the feasible region by solving the feasible region of the vertex set and obtain the effects of feed forward variables on the feasible region. The simulations verify the validity of the method in this paper.

    Two dimensional state estimation in batch process with delayed measurements
    QI Pengcheng, ZHAO Zhonggai, LIU Fei
    2016, 67(9):  3784-3792.  doi:10.11949/j.issn.0438-1157.20151894
    Abstract ( 82 )   PDF (717KB) ( 136 )  
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    This work investigates the state estimation in a batch process based on the particle filter method. Considering that the two dimensional dynamics and the key parameters are obtained online with low accuracy or offline with large time delay, a two dimensional state transition model and delayed measurement model are developed. In addition, a two dimensional state estimation algorithm is proposed by using Bayesian method and the forward-backward smoothing algorithm. The proposed algorithm improves the estimation accuracy by fusing information of previous batches and delayed measurements, and overcomes the influence of the uncertainty of offline sampling period and time delay. The applications in a numerical example and a beer fermentation show the effectiveness of the proposed method.

    A fault diagnosis method for multimode processes based on ICA mixture models
    XU Ying, DENG Xiaogang, ZHONG Na
    2016, 67(9):  3793-3803.  doi:10.11949/j.issn.0438-1157.20160094
    Abstract ( 109 )   PDF (716KB) ( 220 )  
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    For the nature of multimode and non-Gaussian distribution in industrial process data, a fault detection method was proposed for multimode processes based on independent component analysis mixture model (ICAMM). In this method, Bayesian inference and independent component analysis (ICA) were combined to create a probability mixture model; the mode classification of each observation by Bayesian inference and ICA model parameters' setting were accomplished simultaneously; and the global monitoring statistics were established within the Bayesian framework to monitor real-time process changes. In order to solve the problem that traditional variable contribution plot could not indicate the relationships of information transmission among fault variables after fault detection, a fault recognition method for multimode processes was further proposed on the basis of information transfer contribution plot. Three steps were developed in the fault recognition method, including the calculation of variable contributions to the independent component analysis mixture model, the determination of cause-and-effect relationships of fault variables through variable transfer capability and the nearest neighbor transfer entropy, and the finding of fault source variables and fault propagation process. Simulation study on a numerical example and continuous stirring tank reactor (CSTR) system showed effectiveness of the proposed approach.

    Multi-objective optimal strategy for steam power system in steel industry based on electricity equivalent calculation
    CHEN Jun, ZHOU Weiguo, WANG Hai, LI Su
    2016, 67(9):  3804-3811.  doi:10.11949/j.issn.0438-1157.20151584
    Abstract ( 83 )   PDF (439KB) ( 280 )  
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    The steam power system in steel industries is featured by a variety of energy and various energy producers. In this paper, a method to convert energy into electricity equivalent is introduced to analyze the efficiency of energy conversion in the system, and mathematical programming and optimization are employed to improve energy management based on the background of steam power system in a large iron and steel company. With the establishment of mixed integer nonlinear programming model which is multi-objective, the global optimal solution will be achieved by solve the multi-objective-constrained model by LINGO step by step on condition that the objectives, the minimum cost of energy hourly and the maximum exergy efficiency, and the constraints including the capacity of power plants, energy demand and operating cost are set. Pareto front is to be achieved by solving the objective function-the maximum exergy efficiency-with cost constraint by the minimum cost of energy hourly multiplying an over-relaxation which is little bigger than 1. Rationality, feasibility and efficiency of ultimate optimization solution by stepwise multi-objective optimization is to be demonstrated in comparison with solutions by single-objective optimization and multi-objective genetic algorithm. The schedule of effective operation at low cost of steam power system is to be well-founded in theory in accordance with the optimal solution.

    Determination of optimal initial steam pressure of turbine based on relevance vector machine
    LIU Chao, NIU Peifeng, DUAN Xiaolong, LI Guoqiang, ZHANG Xianchen
    2016, 67(9):  3812-3816.  doi:10.11949/j.issn.0438-1157.20151407
    Abstract ( 104 )   PDF (452KB) ( 104 )  
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    In order to calculate the optimal initial pressure effectively, a heat rate forecasting model is presented based on the optimized relevance vector machine (RVM), in which the blended biogeography-based optimization based on the simulated annealing (B-BBO-SA) is adopted to optimize the parameter of RVM. Then, B-BBO-SA is employed to seek the optimal initial pressure under all loads based on the forecasting model. The comparison with B-BBO-SA-SVM show that the B-BBO-SA-RVM has better generalization abilities. In addition, there are some differences between the found optimal initial pressure and the designed one, and the found one can better ensure the turbine run safely and economically.

    Online fault diagnosis in wastewater treatment process by kernel-based weighted extreme learning machine
    XU Yuge, DENG Wenkai, CHEN Liding
    2016, 67(9):  3817-3825.  doi:10.11949/j.issn.0438-1157.20160118
    Abstract ( 109 )   PDF (547KB) ( 303 )  
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    Operation faults in biochemical wastewater treatment process often result in serious issues such as effluent water below quality specification, high operation cost, and secondary environmental pollution, therefore spontaneous and accurate diagnoses are required. Considered the poor accuracy of fault diagnosis induced by imbalanced characteristics of the process data in wastewater treatment, a novel online fault diagnostic model for wastewater treatment process was proposed, i.e., the kernel-based weighted extreme learning machine. Based on extreme learning machine (ELM) theory, weighting scheme was used to resolve the data imbalance and the non-linear mapping of kernel function was used to improve the extent of linear separation. Simulation experiments showed that this online fault diagnostic model has higher measuring precision, better generalization ability, and faster online updating speed, and meet the requirement of accuracy and spontaneity. Therefore, the proposed method can be applied in real-time on-line fault diagnosis in wastewater treatment process.

    A robust particle filter for estimating states in nonlinear process systems with uncertain initial states
    CAO Tingting, ZHANG Zhengjiang, ZHENG Chongwei
    2016, 67(9):  3826-3832.  doi:10.11949/j.issn.0438-1157.20151440
    Abstract ( 55 )   PDF (558KB) ( 129 )  
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    State estimation is critical for both process control and fault detection. A robust particle filter was proposed to estimate states in nonlinear process systems with uncertainty of initial states, which an indirect acceptance criterion was introduced to determine accuracy of the initial states and then to decide the needs for iterative improvement on the initial states by the feedback mechanism of observation bias. In case that the initial states were inaccurate, the iterative improvement strategy would be triggered to adjust particles closer to the true initial states. Therefore, the probability of setting the correct initial states to particles was increased and the accuracy of state estimation was improved through particle filter iteration. When applied to two nonlinear dynamic systems, the proposed particle filter demonstrated much more effectiveness and robustness than the traditional particle filter.

    Analysis of Joule-Thomson effect of real gas system sealed by dry gas
    DENG Chengxiang, SONG Pengyun, MA Ailin
    2016, 67(9):  3833-3842.  doi:10.11949/j.issn.0438-1157.20151892
    Abstract ( 146 )   PDF (598KB) ( 293 )  
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    In a system sealed by dry gas, the Joule-Thomson (JT) effect occurs when the gas flows through the components of filters, valves, orifices and end faces, which may cause the temperature drop of sealing gas, even the appearance of liquid condensation. Generally, the Joule-Thomson effect is represented by Joule-Thomson coefficient. As to the hydrogen, nitrogen, air and carbon dioxide, which are often encountered for the cases of sealing by dry gas, the corresponding Joule-Thomson (JT) coefficients were calculated by four classical equations of state (EOS) of VDW, RK, SRK and PR. Subsequently, those calculated coefficients are compared with the experimental data in the literatures. The JT coefficient curves and Joule-Thomson inversion curves (JTIC) were plotted using the optimal equation of state. As to air and nitrogen through the end faces of dry sealing gas, the gas temperature drops caused by JT effect were calculated by applying the computer program. It shows that the Joule-Thomson effect of real gas, which have important influence on the throttle of dry sealing gas. At room temperature, hydrogen showed exothermic effect, while nitrogen, air and carbon dioxide endothermic (cooling) effect. The corresponding Joule-Thomson (JT) coefficients were calculated by the four classical EOS, the average relative error and maximum relative error of RK equation were the minimum, less than 4% and 10%, respectively. The JT effect of real gas causes large temperature difference in the dry sealing gas, of which the gas pressure more influences on the temperature drop than the gas temperature does. When the pressure is small, the temperature drop by the JT effect can be negligible.

    Preparation of hexagonal plates of magnesium hydroxide and mechanism analysis with first principles
    ZHOU Yonghong, FAN Tianbo, LIU Luping, LI Li, LI Xue, GUO Hongfan, LIU Yunyi
    2016, 67(9):  3843-3849.  doi:10.11949/j.issn.0438-1157.20160045
    Abstract ( 93 )   PDF (2084KB) ( 287 )  
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    Hexagonal plates of magnesium hydroxide were prepared by one-step hydrothermal method with magnesium nitrate or magnesium chloride as starting materials and gaseous ammonia as precipitator. Scanning electron microscope (SEM) and X-ray powder diffraction (XRD) were employed to characterize the products. The energy, electronic structures and population of exposing plane of all developing facets in the magnesium hydroxide crystals were calculated by the first principle methods based on plane wave pseudo-potential theory. The results showed that the P track played a leading role to maintain lattice structure stability of magnesium hydroxide planes. Total surface energy of (001) plane was lower than all the others, while bonding strength of O-Mg bond and H-Mg bond were strong. Thus, (001) plane had a higher thermodynamic stability, giving a reasonable explanation for morphology of hexagonal plates of magnesium hydroxide.

    Fortified continous catalytic properties of immobilized nuclease P1 with surface activated HA amino resin
    HE Linjiao, LIU Xiaojing, HUANG Jinsha, ZHUANG Wei, YING Hanjie
    2016, 67(9):  3850-3860.  doi:10.11949/j.issn.0438-1157.20160280
    Abstract ( 95 )   PDF (2129KB) ( 216 )  
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    The effect of HA amino resin (immobilized enzyme widely-used carrier) geometry and surface activated process on the immobilized nuclease P1's properties was studied. In addition, the dynamic analysis and continuous catalytic properties were also investigated. FESEM, BET and FTIR characterization were utilized to verify that HA amino resin had a great deal of enzymes available hole and the scope of the main hole was 4-30 nm in the immobilized process. Compared with free nuclease P1, the acid resistance and heat resistance of the immobilized enzymes were improved. The study on Michael's Mention kinetics indicated that the substrate affinity and maximum reaction rate of immobilized enzymes decreased; the reusability of after crosslinking group was significantly enhanced compared to physical adsorption and chemical crosslinking groups. The optimized conditions of immobilization were as follows:the enzyme to carrier ratio of 3:20 (mass ratio), enzyme concentration of 0.8 g·L-1 and 10 h immobilized time at pH 6.0. Under these conditions, the immobilized enzyme activity was about 10013 U·g-1. Furthermore, the operating conditions of column flow reactor were designed and optimized. The continuous running time of the reactor was up to 120 h at 30 g·L-1 products nucleotide concentration (hydrolysis rate of 60%), when the reaction temperature was 65℃ with substrate flow rate of 0.75 ml·min-1. This work would be beneficial to the application of nuclease P1 in nucleotide continuous industrial production.

    Start-up and operation of “sluge-micobial film” hybrid ABR used as hydrogen production system
    ZHENG Yang, WANG Luning, ZHANG Baoyi, LI Yongfeng, REN Nanqi
    2016, 67(9):  3861-3871.  doi:10.11949/j.issn.0438-1157.20160112
    Abstract ( 127 )   PDF (871KB) ( 224 )  
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    The new sluge-micobial film hybrid anaerobic baffled reactor (SMHABR) was obtained by the improvement of the original ABR with five compartments and effective volume of 43.2 L. The experimentation studied on the formation of ethanol type fermentation, the hydrogen production capacity and the COD removal capacity. The result of 180 days experiment showed that using brown sugar wastewater as raw material with hydraulic retention time of 12 h, temperature of 35℃±1℃, the system of ethanol type fermentation bacteria could be formatted in 35 days through increasing the influent COD in a phased operation mode. When the influent COD was about 3500 mg·L-1, the maximum hydrogen production was achieved with the total hydrogen production of 44.75 L·d-1. The hydrogen production of the second compartment was larger than that of the other compartments. When the influent COD was about 7100 mg·L-1, the maximum COD removal capacity was achieved with the average total COD removal rate of 49.33%. The maximum hydrogen production and the maximum COD removal rate did not appear at the same time. When the influent COD concentration was too high, the organic acid accumulation in the reactor was too much, resulting in the reactor pH down to 3. Low pH affected the hydrogen production efficiency of the system. Although ethanol fermentation was formed in the system, the hydrogen production capacity was low.

    Precipitation flotation behavior of collagen-peptide based surfactants for Cu(Ⅱ) ions in wastewater
    ZHOU Shengpeng, HUO Wenkai, WANG Ru, LIAO Xuepin, SHI Bi
    2016, 67(9):  3872-3878.  doi:10.11949/j.issn.0438-1157.20160282
    Abstract ( 114 )   PDF (553KB) ( 162 )  
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    Precipitation flotation behaviors of the collagen-peptide based surfactants (anionic CBS and cationic C-CBS) for removal of heavy mental ions in wastewater were studied using low concentration of Cu2+ aqueous solution as simulated wastewater containing heavy metal ions. Factors of wastewater pH, gas velocity, mass concentration of surfactant, flotation time, and initial Cu2+ concentration were investigated thoroughly on efficacy of the Cu2+ removal. Both CBS and C-CBS surfactants exhibited good performance at alkaline condition, which around 90% Cu2+ were removed. With increase in mass concentration of surfactants, the Cu2+ removal was increased using CBS whereas it was decreased using C-CBS. When the gas velocity or flotation time was increased, the Cu2+ removal was enhanced initially and then plateaued afterwards. These results suggested that the collagen-peptide based surfactants can be used in the precipitation flotation for the removal of heavy mental ions in wastewater.

    Tween 80 enhanced-activated sodium persulfate oxidation of PAHs contaminated soil
    JI Hongjun, LONG Tao, CHEN Qiang, HE Yue, LIN Yusuo, YU Ran, ZHU Xin
    2016, 67(9):  3879-3887.  doi:10.11949/j.issn.0438-1157.20160308
    Abstract ( 227 )   PDF (887KB) ( 399 )  
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    In this study, the capabilities of typical non-ionic surfactant Tween 80 and activated sodium persulfate for the oxidation of polycyclic aromatic hydrocarbons (PAHs) in soil were investigated. The mean PAHs desorption efficiency of 37.8% was obtained when 10% (20 g·L-1) Tween 80 was used and it increased to 89.5% after 4 times of soil washing. When citrate complexed ferrous sulfate was chosen as an activator and the Fe(Ⅱ) concentration increased from 0.84 mmol·L-1 to 4.2 mmol·L-1 coupled with 84 mmol·L-1 SPS, the PAHs degradation efficiency increased from 64.3% to 73.5%. However, the PAH removal efficiency would then be suppressed if the Fe(Ⅱ) concentration was continuously elevated. When SPS to Fe(Ⅱ) molar ratio was fixed as 20:1, the increase of the SPS concentration up to 168 mmol·L-1 caused as high as 86.1% of the total PAHs removal rate, which would not be further enhanced with increasing SPS concentration. The presence of 0.25% Tween 80 would increase the PAHs removal rate by 14%. The optimization results showed that the PAHs removal rates of as high as 90.0% could be achieved when the concentrations of Tween 80, SPS, and Fe(Ⅱ) were 0.25%, 42 mmol·L-1 and 2.1 mmol·L-1, respectively. Thus, the activated SPS can be applied to effectively oxidized and removed soil PAHs and the efficiency can be improved with the addition of Tween 80. The Tween 80 coupled SPS oxidation will be an effective technique for PAHs removal from soil.

    Removal of nitrate nitrogen by nanoscale zero-valent iron supported on modified diatomite
    XIU Ruirui, HE Shiying, SONG Hailiang, YANG Linzhang, ZHANG Wan
    2016, 67(9):  3888-3894.  doi:10.11949/j.issn.0438-1157.20160412
    Abstract ( 128 )   PDF (1980KB) ( 319 )  
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    With modified diatomite as support, the composite materials of nanoscale zero-valent iron and modified diatomite (NZVI-CDt) were prepared by using sodium borohydride as reducing agent via the liquid phase reduction method. The NZVI-CDt was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The influences of initial concentrations of nitrate nitrogen (5-30 mg·L-1) and pH (3, 5, 7 and 9) on removal of nitrate nitrogen were investigated, and the final degradation products were detected. The results showed that the iron nanoparticles were highly dispersed on the surface of diatomite and several iron nanoparticles were embedded within the diatomite porous. Iron nanoparticles had a nearly spherical shape with the range of 100 nm. The NZVI-CDt showed efficient removal of nitrate nitrogen. The removal efficiency could reach 90.1% after 60 min at proper conditions:pH 7, initial 20 mg·L-1 concentration of nitrate nitrogen and 0.5141 g NZVI-CDt at the room temperature. Kinetic studies showed that the reduction of nitrate nitrogen by NZVI-CDt followed the pseudo-first-order kinetics. In addition, kobs decreased with increasing nitrate nitrogen concentration.

    Pollutant removal efficiency in upflow microaerobic biofilm reactor treating manure-free piggery wastewater with low COD/TN ratio and high
    WANG Cheng, MENG Jia, LI Jiuling, LI Jianzheng, ZHAO Zhen
    2016, 67(9):  3895-3901.  doi:10.11949/j.issn.0438-1157.20160442
    Abstract ( 81 )   PDF (617KB) ( 145 )  
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    Nitrogen removal from manure-free piggery wastewater (MFPW) with high and low C/N ratio is a great challenge. A novel upflow microaerobic biofilm reactor (UMBR) was constructed to treat the MFPW in the present research. The reactor was operated at 27℃ and a hydraulic retention time of 8.0 h, in which the dissolved oxygen (DO) was less than 1.0 mg·L-1 controlled by refluxing aerated effluent with the reflux ratio decreased from 45:1 to 30:1 by stages. During the 79-day operation, the effect of wastewater characteristics and DO concentration on the UMBR' performance was investigated. The results showed that the internal DO decreased from 0.70 to 0.23 mg·L-1 following the decrease of reflux ratio from 45:1 to 30:1 by stages, and no negative impact on COD removal was found with a well NH4--N oxidation. But the anaerobic ammonium oxidation would be inhibited by a DO above 0.70 mg·L-1, resulting in a decrease in TN removal. Fed with raw MFPW characterized by a COD,NH4--N and TN of 271, 336.7 and 337.4 mg·L-1 with the DO 0.40 mg·L-1 and the reflux ratio 35:1, the average pollutant removal load reached 0.60, 0.94 and 0.91 kg·m-3·d-1, respectively. Though the COD/TN in the feed averaged 0.8, a removal of NH4--N and TN as high as 93.1% and 89.9% was obtained, respectively. Obviously, the filler allowed more activated sludge to grow as biofilm in the UMBR and could construct suitable microenvironments for chemoheterotrophic bacteria, ammonia oxidizing bacteria, autotrophic and heterotrophic denitrifiers, separately. The diversity of physiological groups of bacteria laid the foundation for the excellent pollutant removal in the microaerabic process.

    Simultaneous control of PM2.5 and SO3 by chemical agglomeration collaborative electrostatic precipitation
    HU Bin, LIU Yong, YANG Chunmin, HOU Dawei, YUAN Zhulin, YANG Linjun
    2016, 67(9):  3902-3909.  doi:10.11949/j.issn.0438-1157.20160134
    Abstract ( 113 )   PDF (1054KB) ( 587 )  
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    Chemical agglomeration is one of the effective technology to realize ultar-low emission for coal-fired power plants. The removal of PM2.5 and SO3 from coal combustion by chemical agglomeration was investigated experimentally based on the coal-fired thermal system. The chemical composition of fine particles, the changes of particle size and the concentration of PM2.5 and SO3 were investigated at the chemical reunion chamber and electric outlet. The mechanism of removing PM2.5 and SO3 was analyzed. The results showed that the chemical agglomeration evaporation can increase the average size of particles from 0.1 μm to 3 μm, while the particle compositions were mainly uncharged. The fine particle number concentration was reduced from 5.8×104 cm-3 to 3.2×104 cm-3 and the electric efficiency was increased by 45% at the electric outlet. When SO3 concentration in flue gas increased from 40 mg·m-3 to 100 mg·m-3, the removal efficiency of SO3 of a single chemical agglomeration increased from 42% to 68%, coordinated the electric SO3 removal efficiency by 66% to 86%. The chemical agglomeration collaborative electrostatic precipitation can be efficient for the removal of PM2.5 and SO3.

    Start-up and characterization of nitrogen and COD removal from mature landfill leachate via CANON process
    ZHANG Fangzhai, WANG Shuying, PENG Yongzhen, MIAO Lei, CAO Tianhao, WANG Zhong
    2016, 67(9):  3910-3918.  doi:10.11949/j.issn.0438-1157.20160144
    Abstract ( 96 )   PDF (1335KB) ( 199 )  
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    The mature landfill leachate from sanitary landfill is difficult to treat because of complicated composition, high concentration of ammonia and low C/N. During this study, a CANON (completely autotrophic nitrogen removal over nitrite) process with an intermittent aeration/anaerobic mixing operational mode was applied to remove nitrogen from mature landfill leachate. After domestication of 130 d, the system was stable with the effluent COD,NH4--N and TN (mg·L-1) of 407±14, 8±4 and 19±4 when the influent COD,NH4--N and TN (mg·L-1) were 2050±250, 1625±75 and 2005±352, respectively. Nitrogen removal from mature landfill leachate could be realized via intermittent aeration/anaerobic mixing CANON process with 98.76% of total nitrogen removal efficiency. Besides, the FISH (Fluorescence in situ hybridization) results showed that under this operational mode, both aerobic ammonium oxidation bacteria and anaerobic ammonium oxidizing bacteria accounted for 19.5%±1.3% and 42.7%±5.02%, respectively, which provided a reference for CANON treating mature landfill leachate in engineering application.

    Advanced treatment of coal chemical wastewater using a novel MBBR process with short-cut biological nitrogen removal
    ZHUANG Haifeng, HAN Hongjun, SHAN Shengdao, XUE Xiangdong
    2016, 67(9):  3919-3926.  doi:10.11949/j.issn.0438-1157.20160382
    Abstract ( 118 )   PDF (1998KB) ( 322 )  
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    The biologically pretreated coal chemical wastewater (CCW) still contains a large number of toxic and refractory compounds which has posed great hazard to the environment. In the present work, a novel integration of anoxic moving bed biofilm reactor (ANMBBR) and MBBR with short-cut biological nitrogen removal (SBNR) was employed for the advanced treatment of real CCW. The results indicated the integrated process effectively alleviated the negative effects of toxic inhibitors and the low carbon/nitrogen on biological nitrogen removal. The best performance was obtained at hydraulic residence time of 12 h and nitrate/nitrite nitrogen recycling ratio of 200%. The removal efficiencies of COD, and total nitrogen were 68.1%, 84.0% and 74.7%, the corresponding effluent concentrations were 48.0, 4.8 and 13.9 mg·L-1, respectively, which all met class-Ⅰ criteria of the Integrated Wastewater Discharge Standard. Meanwhile, compared with traditional A2/O process, the novel integrated process had higher removal performance of and TN, especially under the high toxic loading. Moreover, the ANMBBR played a key role in degrading toxic inhibitors, which was beneficial to improve biodegradability (BOD5/COD increased by 0.3) further enhancing SBNR efficiency, and the numbers and kinds of toxic inhibitors decreased by 84.4% and 54.5%, respectively in MBBR. Therefore, the integrated processes could serve as a technically feasible and cost-effective method with potential application for advanced treatment of CCW.

    Cost estimation and optimal cleaning cycle optimization of ash fouling for air cooling condenser
    ZHAO Bo, YANG Shanrang, LIU Zhichao, CAO Shengxian
    2016, 67(9):  3927-3935.  doi:10.11949/j.issn.0438-1157.20160152
    Abstract ( 99 )   PDF (816KB) ( 143 )  
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    The suspended particulate matter of cooling air easily agglomerated the ash fouling in the finned channel of air cooling condenser (ACC). Its low thermal conductivity severely reduced the transfer performance of ACC, endangered the security and affected the thermal efficiency for direct air cooling (DAC) plant. Aiming at minimizing the year accumulation cost caused by ash fouling, a new optimization algorithm of optimal cleaning cycle of ACC was presented in this paper based on product loss and cleaning maintenance costs. Then, by jointing the cost of redundant area of ACC, an evaluation and calculation model of ash fouling cost was established. Based on the ACC parameters of 600 MW DAC power plant, the drop rate prediction model of ash fouling resistance was established by the experiment data of site online monitoring. The example analysis results showed that the best cleaning cycle was 28.3 d and the annual cleaning frequency was 8 times for the 600 MW DAC plant, and then, the annual ash fouling cost of unit capacity plant was 4528.3 yuan·MW-1·a-1. According to the national installed capacity of 143 million kW in 2014, the annual accumulation cost of ash fouling was as much as 648 million yuan·a-1 for our whole country. Compared with the site operation condition of annual cleaning 2 times, the ash fouling cost can be saved 2868.1 yuan·MW-1·a-1 and the annual accumulation eliminable cost was 410 million yuan·a-1.

    Micro-mechanism of scaling in a cooling system under deep mine
    HAN Qiaoyun, YANG Xiaojie, ZOU Shenghua
    2016, 67(9):  3936-3945.  doi:10.11949/j.issn.0438-1157.20151962
    Abstract ( 89 )   PDF (4374KB) ( 255 )  
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    The micro-mechanism of the scaling of pipelines in the cooling system under deep mine was studied. Firstly, the composition and content of the ions in the mining water were determined by the full analysis of water quality, and then the chemical model and mathematical model were built, finally, the adsorption of scaling ions on iron surface was calculated by using the VASP software based on density functional theory (DFT). The result shows that, ① the scaling of the cooling system includes the combination of Ca2+ and CO32+ and the transform of MgCO3, CaSO4 to CaCO3; ② the scaling ions (Ca2+,HCO-,Mg2+ and SO42-) are the main factors leading to the CaCO3 scaling of the cooling system pipelines under deep coal mine and Mg2+ and SO42- could restrain the scaling. The research is of great importance to the understanding of the scaling of the cooling under deep coal mine, pretreatment, and descaling, in order to guarantee the cooling effect and production safety for the geothermal engineering.

    Enhancement of partial nitrification performance of aerobic granular sludge by coordinating C/N loading rate
    QIAN Feiyue, LIU Xiaopeng, ZHANG Nianqi, WANG Xiaoyi, WANG Jianfang, LIU Guoxun
    2016, 67(9):  3946-3953.  doi:10.11949/j.issn.0438-1157.20160120
    Abstract ( 73 )   PDF (2059KB) ( 200 )  
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    In order to start up an autotrophic partial nitrification process, the coordinated control of the influent C/N loading rate was carried out in the lab-scale sequencing batch reactor (SBR) inoculated with heterogeneous granular biomass. During the operation period, the evolution of granule size distribution, extracellular polymeric substances (EPS) composition and dynamics activities of functional microbes were also investigated to elaborate main factors for the conversion of sludge characteristics. The results showed that the nitrite nitrogen (NO2--N) accumulation rate of SBR would reach around 1.34 kg·(m3·d)-1, with the persistent enhancement of ammonia-oxidizing bacteria (AOB) activity and the effective inhibition of nitrite-oxidizing bacteria (NOB), represented by specific removal (μNO3-N) and NO2--N accumulation (μNO3-N) rates, respectively. Moreover, the mean diameter of sludge granular increased from 1.4 mm to around 2.2 mm with the color of reddish brown, while its settling ability was improved significantly. Benefited from the accumulation of EPS contents, AOB could be immobilized by granular sludge effectively, even if the settling time of reaction cycle was set at 3 min. In addition, the selective inhibition of NOB caused by both free ammonia (FA) and free nitrous acid (FNA) during the aeration period was the other main factor for stable partial nitrification.

    Membrane fouling and dealing with domestic sewage in MBR of homogeneous enhanced PMIA hollow fiber membranes
    CHAI Lihong, XIAO Changfa, QUAN Quan, LIU Hailiang, CHEN Mingxing, ZHAO Bin
    2016, 67(9):  3954-3964.  doi:10.11949/j.issn.0438-1157.20160059
    Abstract ( 119 )   PDF (3807KB) ( 203 )  
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    The fouling mechanisms of the homogeneous enhanced aromatic poly(m-phenyleneisophthalamide) (PMIA) hollow fiber membranes were determined by experimental data fitting to pore blocking model or cake fouling model, and combined with the membrane pore size distribution, particle size distribution of filter mediums and the membrane resistance distribution during ultrafiltration. Three materials (CaCO3 suspension, activated sludge and BSA solution) which could induce fouling were used to be filter mediums. In addition, homogeneous enhanced PMIA hollow fiber membranes were applied to membrane bioreactor (MBR) system to deal with domestic sewage. At the meantime, the cleaning effects of water and chemical were analyzed by field emission scanning electron microscopy (FESEM), and the change of quality fraction of inorganic elements after fouling and cleaning of membrane outer surface was performed by energy dispersive X-ray spectrometer (EDX). The results showed that when the filter medium was BSA, the linear correlation coefficient (t-t/V) was 0.9940. Thus, the main type of the membrane fouling in ultrafiltration of BSA solution was attributed to pore blocking. Owing to the linear correlation coefficient(V-t/V) was 0.9733 and 0.9994, respectively, the membrane fouling caused by CaCO3 suspension and activated sludge was conformed to cake layer formation. Moreover, the MBR operating results showed that the average removal of COD,NH4+-N and TP was up to 97.78%, 96.71% and 49.81%, respectively, being beneficial to improve the effluent quality. Furthermore, the chemical cleaning experiment demonstrated that the kinds of inorganic elements of the membrane outer surface were close to the original film. The pollutants were easier to be removed by chemical cleaning.

    Matching rules between dispersants and Shenfu coal slurriability
    SONG Chengjian, QU Jianlin, YANG Zhiyuan, WANG Guangheng, YANG Fusheng, ZHOU Anning
    2016, 67(9):  3965-3971.  doi:10.11949/j.issn.0438-1157.20160108
    Abstract ( 84 )   PDF (684KB) ( 163 )  
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    The matching rules between dispersants and Shenfu coals (SFC) slurriability were investigated by using attenuated total internal reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Based on the ATR-FTIR results of four kinds of dispersants, the hydrophilic groups (-OH、-C-O、-C=O、-SO3-) and hydrophobic groups (-CH3、CH2、-C=C) were calculated by Gaussian peak separation method, respectively, and the effects of hydrophilic and hydrophobic groups on the SFC slurriability were also discussed. The results showed that the slurry concentration of Shenfu coal water slurry (SFCWS) with ZFZ dispersants was the highest, but with MZS dispersants it was the lowest. The results indicated that ZFZ was a good kind of dispersant for SFCWS because of its less hydrophobic groups and more hydrophilic groups. A slurry concentration prediction model and matching degree model between the dispersants and SFC were further proposed by partial least squares method. The models were proved by using JJN, DNC and SMS dispersants with the errors of predictive slurry concentration within ±1%. The change trend of predictive slurry concentration and matching degree was consistent with the actual slurry concentration.

    Preparation of methylimidazole hydrochloride/oxalic acid type deep eutectic solvent and its application in oxidative desulfurization of model oil
    HOU Liangpei, ZHAO Rongxiang, LI Xiuping, SHI Weiwei
    2016, 67(9):  3972-3980.  doi:10.11949/j.issn.0438-1157.20160330
    Abstract ( 346 )   PDF (650KB) ( 473 )  
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    Methylimidazole hydrochloride/oxalic acid ([HMIM]Cl/H2C2O4) type deep eutectic solvent was synthesized by a simple heating and stirring mixture of methyl imidazole hydrochloride and oxalic acid. The removal of dibenzothiophene (DBT) in model oil was carried out by using[HMIM]Cl/H2C2O4 as a catalyst and hydrogen peroxide as oxidant. The effect of different reaction parameters such as different desulfurization system, reaction temperature, catalyst amount, molar ratio of hydrogen peroxide to sulfur and the type of sulfur-containing compounds in oil on the desulfurization rate was investigated. The experimental results indicated that the removal rate of DBT can reach 92.2% under the optimum conditions of 5 ml model oil, 1.25 ml of[HMIM]Cl/H2C2O4 and O/S mole ratio of 12 in 140 min and 40℃. The kinetics analysis showed that the oxidative desulfurization system was in accord with the first order reaction kinetics equation. The catalyst was reused for 7 times without significant decrease in activity.

    Naphthalene biodegradation by Acinetobacter johnsonii
    JIANG Yan, ZHANG Xiaohua, YANG Ying, ZHANG Xianming
    2016, 67(9):  3981-3987.  doi:10.11949/j.issn.0438-1157.20151992
    Abstract ( 92 )   PDF (604KB) ( 255 )  
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    Naphthalene, typical of polycyclic aromatic hydrocarbons, is highly poisonous and hardly degradable. As the typical petroleum hydrocarbon composition, it is a severe environmental pollutant, and therefore there exists great difficulty in the bioremediation of oil-contaminated sites. Due to its poor water solubility, researches on naphthalene degradation are hindered seriously. In this paper, the strain of Acinetobacter johnsonii isolated from waste oil is employed to study naphthalene biodegradation with the ability both to degrade petroleum hydrocarbon and to wet inorganic impurities. The reaction conditions are optimized based on the researches on degradation factors and the biodegradation characteristics of naphthalene are manifested in the range of 50 to 2000 mg·L-1. The dynamics behavior of A. johnsonii is studied on the degradation of naphthalene through the comparison of the Monod model and the Haldane model. The results indicated that the strain could utilize naphthalene as sole carbon and energy source to metabolize and 2000 mg·L-1 naphthalene could be entirely degraded within about 146 h at 5% inoculum volume and 37℃. The Haldane model is suitable to describe cell growth and the substrate degradation behaviors while the Monod model is appropriate to depict naphthalene biodegradation with low initial concentration.

    Preparation of a series of fine chemicals by blast furnace slag
    SHEN Xingmei, LI Liaosha, WU Xingrong, WANG Ping, CHU Liang
    2016, 67(9):  3988-3994.  doi:10.11949/j.issn.0438-1157.20160220
    Abstract ( 110 )   PDF (664KB) ( 199 )  
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    On the basis of previous works, preparation of a series of fine chemicals by blast furnace slag was researched further and deeply, and the process route was developed. The first product, gypsum, was obtained by sulphuric acid hydrolysis. The optimum conditions for preparing aluminum silicate were:water-slag ratio 7:1, pH 4.0 and adding small pieces of Al plates to remove iron. The optimum conditions for preparing magnesium aluminum spinel were:mass percent of urea 65% and amount of Na2S2O4 5%. The chemical composition of the three products was in accord with the relative standards. This process had the advantages of short flow, low cost, etc. Almost all valuable contents in the slag were used, and no residue was discharged. Thus, it had better environmental benefit.

    Treatment of tanning wastewater by integrated process consisted of coagulation, anaerobic baffled reactor and anoxic/aerobic-membrane bioreactor
    NIE Lijun, ZHONG Huawen, ZHOU Rujin, LIN Peixi, DENG Zecong, ZHAO Meitian, LIN Zhiwu
    2016, 67(9):  3995-4003.  doi:10.11949/j.issn.0438-1157.20160123
    Abstract ( 140 )   PDF (777KB) ( 269 )  
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    Tanning wastewater is difficult to be treated due to its high concentration of suspended solids (SS), organic matters and chroma. In this work, an integrated process was proposed to treat the wastewater, which consisted of coagulation, anaerobic baffled reactor (ABR) and anoxic/aerobic-membrane bioreactor (A/O-MBR). The influences of coagulation conditions, ABR startup strategy and operation parameters (HRT, DO and temperature, etc.) on treatment effects were mainly investigated. The results showed that during the coagulation process (pH of 9.0-10.0 and PACl dosage of 350-450 mg·L-1), the average removal rates of SS, chroma, total Cr and COD were 70.4%, 73.9%, 97.7% and 37.9%, respectively. Based on the strategy of stepped-loading, the ABR process startup was finished within 50 d, and after that a 68.2% of COD removal rate was achieved at the HRT of 20 h and temperature of 30℃. Through the optimizations of HRT (6 h) and DO (DO 2.0-3.0 mg·L-1) in the A/O-MBR the removal rates of COD and NH4-N were 67.7% and 81.3%, respectively. As a result, the final effluent quality well met the first class standard of DB 44/26-2001, demonstrating that the integrated process proposed in this paper was very promising to treat tanning wastewater.

    Characteristic pollutions during incineration of waste resin buttons
    WANG Sijia, HE Pinjing, SHAO Liming, ZHANG Hua
    2016, 67(9):  4004-4012.  doi:10.11949/j.issn.0438-1157.20151960
    Abstract ( 79 )   PDF (5292KB) ( 260 )  
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    Urea-formaldehyde resin (UFR) and unsaturated polyester resin (UPR) are the most widely used raw materials in the manufacturing of buttons, in which pigments containing heavy metals and chlorine are often added. As one kind of typical hazardous waste, non-biodegradable resin button waste is more suitable to be treated by incineration. In this study, thermogravimetric analysis (TGA) coupled with differential scanning calorimeter, TGA coupled with Fourier transform infrared spectroscopy and lab-scale tube furnace experiments were carried out with UFR and UPR button wastes to investigate the characteristic decomposition temperatures, the potential gaseous pollutions and the distribution of heavy metals in the process of incineration, which could provide scientific basis for the technology optimization and pollution control. The results showed that UFR button waste decomposed at 240-600℃ with gaseous NO generation, and UPR waste decomposed at 180-600℃, producing CO2, H2O, CO, CHn, R OH, R CHO and R COOH. The existence of chlorine in the resin button waste and the formation of these organic compounds can promote the formation of dioxin and other chlorinated aromatic compounds. The contents of Pb, Zn, Cu, Bi and Ti in the resin button wastes were relatively high because of the addition of pigments like PbCO3, Pb(OH)2 and BiOCl, etc. Based on their migration behavior during incineration, Pb and Bi should be made great concerns for pollution control.

    Coordination of electro-osmotic and Fe-persulfate oxidation process on sewage sludge deep-dewatering
    LI Yalin, LIU Lei, ZHANG Yi, WEI Tian, SHI Dan
    2016, 67(9):  4013-4019.  doi:10.11949/j.issn.0438-1157.20160177
    Abstract ( 209 )   PDF (1737KB) ( 256 )  
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    Dewatered sewage sludge of sewage treatment plant was studied by self-made experimental device dewatering based on electro-osmotic-advanced oxidation process which would be influenced by the dosage of persulfate, proportion of ferric salt and persulfate, voltage gradient and the thickness of dewatered sewage sludge. The results showed that the combination of electro-osmosis-advanced oxidation technology can improve the dewater ability. The water content can be reduced to below 60% with sludge amount of 140 g, persulfate dosage of 100 mg·(g DS)-1, Fe2+/persulfate of 1:1, mechanical pressure of 17.59 kPa and controlling initial voltage of 11 V·cm-1. Electro-osmotic-advanced oxidation process can ensure fully use of oxidation ability of to improve the sludge dewater ability based on the mechanism of reduction of electric field and electronic metastasis reaction, making persulfate fully activated compared with sludge dewatering by activated persulfate. Better than the traditional electro-osmosis sludge dewatering, more amount sludge can be treated one time and sludge cake uniformity can be highly improved for the subsequent transportation and settlement.

    Preparation and characterization of soy β-conglycinin-dextran nanogels based on Maillard reaction
    FENG Jilu, QI Junru, WENG Jingyi, LIU Qianru, CAO Jing, CHENG Meng
    2016, 67(9):  4020-4026.  doi:10.11949/j.issn.0438-1157.20160046
    Abstract ( 109 )   PDF (1579KB) ( 269 )  
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    The novel protein-polysaccharide nanogels were fabricated through a combination of Maillard reaction and self-assembly method, which is facile, safe and green. First, amphiphilic soy β-conglycinin-dextran conjugates (SDC) were prepared by grafting dextran onto soy β-conglycinin via Maillard dry-heating reaction. Then, a heat treatment above the denaturation temperature of protein was used to form soy β-conglycinin-dextran nanogels (SDN). The morphology observation indicated that SDN were of spherical shape with core-shell structures, and the zeta-potential study further verified that soy β-conglycinin was covered with nonionic dextran. The surface hydrophobicity investigation displayed that the conformation of protein was changed and the hydrophobic groups of soy β-conglycinin were exposed to the surface of protein. Therefore, several hydrophobic compartments were formed in the core. The nanogels were pretty stable against long-term storage and pH change. These valuable properties and the low toxicity of nanogels may provide a promising way to deliver hydrophobic compounds.