A型分子筛对甲烷水合物生成的影响

The porous medium has an important effect on hydrate formation. In this paper, the formation process and the gas storage capacity of the methane hydrate were investigated with A-type zeolite and Sodium Dodecyl Sulfate (SDS) existing in the system. The results show that A-type zeolite can influence methane hydrate formation. At the temperature of 273.5 K and pressure of 8.3 MPa, the distilled water with A-type zeolite can form methane hydrate with gaseous methane in 12 hours. The formation process of the system with A-type zeolite was quite steady and the amount of A-type zeolite can influence the gas storage capacity significantly. The adding of A-type zeolite with 0.067 g•(g water)－1 into 2×10－3 g•g－1 SDS-water solution can increase the gas storage capacity, and the maxi-mum increase rate was 31%. Simultaneously the promotion effect on hydrate formation of 3A-type zeolite is much more obvious than that of 5A-type zeolite when the water adding amounts are 0.033 g•g－1 and 0.067 g•g－1 at the experimental conditions.     

雷丸的中性金属蛋白酶的分离纯化、酶学性质及体外驱虫活性

A neutral metalloprotease was purified from the cultured mycelia of Laccocephalum mylittae, an effective medicinal fungus widely used in anthelmintic therapy. The protease was purified to homogeneity with 31.85-fold purification and a final yield of 21.76%. The subunit molecular weight of the protease is about 40000 estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum reaction pH and temperature are 7.5 and 50ºC, respectively. The protease activity is largely enhanced by Ca2+, but highly inhibited by tetrasodium ethylenediaminetetraacetate (EDTA), a metal-chelator, suggesting that the enzyme is a metalloprotease. The Michaelis-Menten constan Km and Vmax value for casein substrate are 6.09 mg&;#8226;ml－1 and 21.32 μg&;#8226;min－1&;#8226;ml－1, respectively. In vitro anthelmintic tests of the protease exhibit distinct lethal effects on the third stage larvae (L3) of Ascaris suum. Scanning electron microscopy and SDS-PAGE analysis indicates that the proteolysis of larvae proteins caused by this protease may relate to the anthelmintic activity of L. mylittae.     

氨改性的介孔二氧化硅的直接合成和CO2吸附

Amine-functionalized mesoporous silica was prepared by using lauric acid and N-stearoyl-l-glutamic acid as structure directing agents via the SN+-I mechanism and applied to CO2 adsorption at room temperature. With γ-aminopropyltriethoxysilane as co-structure directing agent and due to the direct electrostatic interaction with anionic surfactant, most of the amino groups were uniformly distributed at the inner surface of pores and the performance was stable. The amine-functionalized mesoporous silica was characterized by Fourier transform infrared spectrometer, X-ray diffraction, nitrogen physisorption and thermogravimetric analysis. The CO2 adsorption capacity was measured by digital recording balance. At the room temperature and under the atmospheric pres-sure, the adsorption capacity of LAA-AMS-0.2 for CO2 and N2 is 1.40 mmol•g1 and 0.03 mmol•g1, respectively, indicating high separation coefficient of CO2/N2.     

面包酵母No.6催化不对称合成(2S,5S)-2,5-已二醇反应特性

Baker’s yeast number 6 was selected by screening. It showed good catalytic activity and enantioselectivity for asymmetric reduction of 2,5-hexanedione to produce (2S,5S)-2,5-hexanediol. Gas chromatography-mass spectrometry (GC-MS) revealed that the intermediate was (S)-5-hydroxyhexane-2-one. Reduction of 2,5-hexanedione proceeded in a two-step reaction. The hydroxyketone was initially formed, and this intermediate was further re-duced to the diol. Factors influencing the product yield and the enantiomeric excess of the reduction of 2,5-hexandione catalyzed by baker’s yeast number 6 were investigated. Higher concentration (≤100 mmol•L－1) of 2,5-hexandione did not influence 5-hydroxyhexane-2-one production, but 2,5-hexanediol production was inhibited by excess accumulation (＞30 mmol•L－1) of intermediate. The optimal conditions were glucose as the co-substrate at an initial glucose concentration of 20 g•L－1, 34C, pH 7.0 and cell concentration 60 g•L－1 (cell dry mass). Under the optimal condition and an initial substrate concentration of 30 mmol•L－1, the yield of 2,5-hexandiol was 78.7% and the enantiomeric excess of (2S,5S)-2,5-hexandiol was 94.4% for 24-h reduction.     

用CuO/A12O3/堇青石催化剂选择性催化还原脱硝的实验和动力学研究

The CuO/γ-Al2O3/cordierite catalyst, after being sulfated by sulfur dioxide (SO2) at 673 K, exhibits high activities for selective catalytic reduction (SCR) of nitrogen oxide (NO) with ammonia (NH3) at 573-723 K. The intrinsic kinetics of SCR of NO with NH3 over CuO/γ-Al2O3/cordierite catalyst has been measured in a fixed-bed reactor in the absence of internal and external diffusions. The experimental results show that the reaction rate can be quantified by a first-order expression with activation energy of 94.01 kJ•mol1 and the corresponding pre-exponential factor of 3.39×108 cm3•g1•s1 when NH3 is excessive. However, when NH3 is not enough, an Eley-Rideal kinetic model based on experimental data is derived with Ea of 105.79 kJ•mol1, the corresponding A of 2.94×109 cm3•g1•s1, heat of adsorption ΔHads of 87.90 kJ•mol1 and the corresponding Aads of 9.24 cm3•mol1. The intrinsic kinetic model obtained was incorporated in a 3D mathematical model of monolithic reactor, and the agreement of the prediction with experimental data indicates that the present kinetic model is adequate for the reactor design and engineering scale-up.     

D318阴离子交换树脂对铼（VII）的吸附

The adsorption and mechanism of Re(VII) on resin D318 were studied using chemical methods and IR spectrometry. At pH 5.2, the static and dynamic saturation adsorption capacities were 351.4 and 366.5 mg&;#8226;g&;#61485;1, respectively. The adsorption behavior obeyed the Freundlich empirical equation and the adsorption rate constant k298 was 6.37×10&;#61485;4 s&;#61485;1. The desorption percentage was up to 99.7% when 2.0 mol&;#8226;L&;#61485;1 KSCN was used for dynamic desorption.     

大团囊虫草L2分离鉴定及其发酵工艺优化

A strain isolated from the fruiting body of a fungus parasitized on Elaphomyces was identified as Cordyceps ophioglossoides based on the morphological characteristics and the analysis of ITS-5.8s rDNA sequence. The optimal medium composition (g•L－1), containing sucrose 66.0, yeast powder 10.0, silkworm chrysalises digest 30.0, MgSO4•7H2O 0.4, and KH2PO4 0.4, was found using fractional factorial design and a central composite design, and the optimization of cultural conditions obtained a result of seed age 6 days, inoculum size 6% (by volume), initial pH 5.6, temperature 24°C, shaking speed 160 r•min－1 by one-factor-at-a-time method. The maximum biomass reached about 20.2 g•L－1 after 90 hours culture under the optimal conditions. Elementary pharmacological activities showed that mycelia of C. ophioglossoides L2 from submerged culture promoted uterus growth in estrogen- depleted mice. In the 15-litre scale-up fermentation, the mycelial biomass was around 19.1 g•L－1, indicating a promising prospect for this biotechnology and the potency to develop its medical value.     

新筛选菌种Sphingopyxis sp.USTB-05对微囊藻毒素的生物降解

A promising bacterial strain for the biodegradation of Microcystins (MCs) was isolated from Dianchi lake in China and identified as Sphingopyxis sp. USTB-05 by the analysis of 16s rDNA. Initial MC-RR of 42.3 mg&;#8226;L－1 was completely degraded by USTB-05 within 36 h, which was a relatively high biodegradation rate of MC-RR. With the cell-free extract (CE) of Sphingopyxis sp. USTB-05, MC-RR was biodegraded at a more rapid biodegradation rate compared with its strain, so that initial MC-RR of 42.3 mg&;#8226;L－1 was completely biodegraded within 10 h. During the bio-reaction of MC-RR catalyzed by CE, two intermediate metabolites and a dead-end product of MC-RR were observed on HPLC profiles and all of them had similar scanning profiles in the wavelength from 200 to 300 nm, indicating that the group of Adda in all products of MC-RR remained intact.     

苯为前驱体的稠环芳烃的自由基反应机理的量子化学研究

The free-radical growth mechanisms for the formation of polycyclic arenes (PCAs) were constructed based on the block unit of benzene, and were calculated by the quantum chemistry PM3 method. Two kinds of reaction paths are proposed and discussed. The calculation results show that the formation of PCAs is only controlled by the elimination of H atom from benzene, and the corresponding activation energy is 307.60 kJ•mol－1. H2 is only the ef-fluent gas in our proposed reaction mechanism, and the calculation results are in accord with the experimental facts.     

突变株CTM2降解苯酚和4-氯酚的生物降解特性

The biodegradations of phenol and 4-chlorophenol (4-cp) were studied using the mutant strain CTM 2 obtained by the He-Ne laser irradiation on wild-type Candida tropicalis. The results showed that the capacity of the CTM 2 to biodegrade 4-cp was increased up to 400 mg•L－1 within 59.5 h. In the dual-substrate biodegradation, both velocity and capacity of the CTM 2 to degrade 4-cp increased with low-concentration phenol. A total of 400 mg•L－1 4-cp was completely degraded within 50.5 h in the presence of 300 mg•L－1 phenol. The maximum 4-cp biodegradation could reach 440 mg•L－1 with 120 mg•L－1 phenol. Low-concentration 4-cp caused great inhibition on the CTM 2 to degrade phenol. In addition, the kinetic behaviors were described using the kinetic model proposed in this lab.     

一体式平板膜生物反应器处理维生素制药废水中试研究

采用规模为5 m~3·h~(-1)左右的一体式平板膜生物反应器对维生素制药废水进行了中试研究.试验结果表明,用此装置处理维生素制药废水,出水水质稳定良好.工艺对COD和NH_4~+-N的去除率分别达到80%和90%以上,出水完全达到了发酵类制药工业水污染物排放标准(GB21903-2008)的排放要求;当HRT分别取12,22、26h时,对系统去除率有较大的影响;污泥浓度是影响膜通量的一个重要因素,污泥质量浓度应控制在7 g·L~(-1)左右;虽然污泥的沉降性能非常差,SV平均值为97.8%,但由于膜的高效截留作用,反应器不受污泥的性状的影响.     

Toluene degradation by a water/silicone oil mixture for the design of two phase partitioning bioreactors

Toluene degradation performances were studied in a 10 L Two-Phase Partitioning Bioreactor (TPPB).The liquid phase consisted of a mixture of water and PDMS 50 (PolyDiMethylSiloxane,i.e.silicone oil,viscosity of 46 maa·s) in the volume ratio of 75％/25％.Two series of experiments were carried out:in the first,the reactor was sequentially supplied with toluene whereas in the second,toluene was continuously supplied.Activated sludge from the wastewater treatment plant of Beaurade (Rennes,France) was used at an initial concentration of 0.5 dry mass g· (mixture L)-1.The elimination capacity (EC) was investigated as well as the change in biomass concentration over time.Toluene biodegradation was very efficient (removal efficiency,RE =100％) for toluene flows ranging from 0.2 to 1.2 ml· h-1,corresponding to elimination capacities of up to 104 g· m-3· h-1.For a toluene flow of 1.2 ml·h-1,the biomass concentration measured at the end of the experiment was 4.7 dry mass g.(mixture L)-1.The oxygen concentration in the liquid phase was clearly not a limiting factor in these operating conditions.Based on these results,an extrapolation leading to the design of a large-scale pilot TPPB can now be considered to study toluene degradation performances in industrial conditions.     

喷射环流膜生物反应器水力特性的研究

通过清水试验,确定了喷射环流膜生物反应器的最大吸气量,探讨吸气量、循环水量等因素对气含率、液相循环速度的影响,测定膜组件加入前后的气含率、液相循环速度大小,并与已有的生化反应器进行了比较.结果表明,装置的最大吸气量可达到0.67 m~3·h~(-1)吸气量是影响气含率的主要因素,并且随着吸气量的增加,气含率也随着增加;循环水量是影响液相循环速度的主要因素,随着循环水量的升高循环液速升高;膜组件的加入对气舍率、液相循环速度的影响非常小,与已有的生化反应器比较,JLMBR在水力特性方面具有明显的优势.所得结果可以为该类反应器的放大设计提供借鉴.     

曝气量对不同填料CANON反应器运行效率的影响

<正>引言一般而言,生物脱氮是采用常规的硝化反硝化工艺去除的,但此工艺对大多数高氨氮废水而言,并不适用,这是因为高氨氮废水往往会面临碳源不     

Removal of dimethyl sulfide in a thermophilic membrane bioreactor

BACKGROUND: Several sources such as the paper and pulp industry and waste treatment plants emit waste gases containing volatile organic sulfur compounds at elevated temperature. Since cooling the hot gases increases the operational cost of biological reactors, application of thermophilic microorganisms could be a cost‐effective solution. The objectives of this study were to investigate the possibility of removal of dimethyl sulfide from waste gases under thermophilic conditions (52 °C) in a membrane bioreactor and to examine the long‐term stability of the reactor at elevated temperature. The effects of operating conditions such as gas residence time, nutrient supply, temperature decrease and short‐term shutdown on elimination capacity were investigated. RESULTS: A maximum elimination capacity of 54 g m^?3 h^?1 (0.108 g m^?2 h^?1) was obtained at a mass loading rate of 64 g m^?3 h^?1 (0.128 g m^?2 h^?1) with a removal efficiency of 84% at a gas residence time of 24 s. The long‐term operation of the thermophilic membrane bioreactor was followed for 9 months. Although the removal efficiency decreased to 50% after 3 months of continuous operation, it recovered (>96%) after the excess biomass was removed by applying high‐velocity liquid recirculation. CONCLUSION: This study demonstrated that the dimethyl sulfide removal is possible in a thermophilic membrane bioreactor with an elimination capacity of 54 g m^?3 h^?1 (0.108 g m^?2 h^?1) at a gas residence time of 24 s. Copyright © 2008 Society of Chemical Industry     

Oxidation of ethanol vapors in a spiral bioreactor

A fixed film spiral bioreactor containing immobilized activated sludge microorganisms has been used to degrade ethanol vapors. The effect of air flow rate, and ethanol feed concentration on elimination capacity has been investigated. Air flow rate is varied in the range from 2?34 to 40?0 dm³ min^?1. Ethanol feed concentration is varied in the range from 600 to 7000 ppmv. In the concentration range studied, the elimination capacity increased proportionately with an increase in feed concentration. However, the elimination capacity decreased significantly at flow rates greater than 20 dm³ min^?1 owing to insulfficient residence time. The maximum elimination capacity observed was 185 g ethanol h^?1 m^?3 of reactor volume. Critical ethanol loading, defined as the maximum loading to achieve greater than 99% elimination at various residence times have been determined. These data are extremely useful in designing bioreactor for large scale applications.     

以污泥酸性发酵产物为碳源生物处理模拟酸性矿山废水的工艺特性

以污水处理厂污泥的酸性发酵产物为硫酸盐还原菌(SRB)的碳源,在厌氧膨胀颗粒污泥床(EGSB)反应器中,研究了生物处理模拟酸性矿山废水(AMD)的工艺特性及影响因素。试验结果表明,污水厂污泥的酸性发酵产物可作为SRB的合适碳源。常温(20℃)条件下,当AMD中SO24-浓度为3000 mg.L-1,pH值3.0,EGSB反应器中液体升流速度为5.0 m.h-1,水力停留时间HRT=13.8 h,碳源COD/SO24-比值取1.0左右,进水SO24-负荷为5.22 kg SO24-.m-3.d-1时,SRB的还原能力可达到3.32 kg SO24-.m-3.d-1,SRB的比还原能力为0.356 kg SO24-.(kg VSS)-1.d-1。AMD处理出水pH值可达6.0,SO24-还原率达到63.6%,COD去除率为45.1%,重金属Fe2+、Mn2+、Ni2+、Zn2+、Cu2+去除率均在89%以上。出水pH值和重金属离子浓度均满足排放标准。     

曝气生物滤池在印染废水回用处理中的应用

采用曝气生物滤池(BAF)工艺对经兼氧-好氧生化预处理后的印染废水进行中试规模的深度处理试验研究.结果表明,在进水COD约为100～250mg·L~(-1)、SS质量浓度约为80～120mg·L~(-1)、色度约为30～50倍的条件下,当BAF水力负荷为1.0m~3·m~(-2)·h~(-1),气水体积比4:1时,出水COD≤50 mg·L~(-1),ρ(SS)≤20 mg·L~(-1),色度≤20倍,出水水质可满足生产工艺对回用水的水质要求.     

EGSB-SBR组合工艺对城市生活污水处理的试验研究

采用EGSB+SBR组合工艺对邯郸市生活污水进行了试验研究.结果表明,在常温下进水COD为245～420mg·L~(-1),EGSB反应器的水力停留时间为3h,反应器COD容积负荷达到3.5 kg·m~(-3)·d~(-1),上升流速达到6.5m·h~(-1)时,COD去除率为95%(COD<60mg·L~(-1)),但氨氮去除效果不佳,故采用SBR工艺为后续处理工艺,其出水的氮、磷等指标达到国家一级排放标准(GB8978-1996).     

减压膜蒸馏法稀碱液浓缩过程研究

以聚偏氟乙烯疏水膜为材料,采用减压膜蒸馏技术在较高真空度下浓缩硫化钠溶液,研究了各种条件对膜通量的影响.结果表明,当进料温度80℃、真空度为80kPa、流速为0.99m·s~(-1)时,质量分数4.6%的硫化钠溶液VMD膜通量为23.7 kg·m~(-2)·h~(-1);连续运行时,将稀碱液浓缩5倍后,膜通量仍维持在10.6kg·m~2·h~(-1),用稀盐酸清洗后膜通量恢复到初始值的95.6%;浓缩过程产水电导维持在10μS·cm~(-1)以下,脱盐率大于99.99%.