Ability of Bacillus mucilaginosus GY03 Strain to Adsorb Chromium Ions

A research with Bacillus mucilaginosus cultured in nitrogen-free medium for forming a flocculant material to adsorb Cr+6 was conducted to determine the effects of different pH, volume, treatment time, and chromium (Ⅵ) concentrations on chromium (Ⅵ) adsorption by microbial flocculant (MBF), which was produced from the B. mucilaginosus GY03 strain. The results showed that MBF had outstanding flocculation on chromium (Ⅵ). Based on the results of a oneway experiment and actual wastewater treatment conditions, the optimum conditions, obtained by using orthogonal experiments, for chromium (Ⅵ) adsorption by MBF were: Cr6+ solution pH of 9, flocculant material volume of 15 mL,treatment time of 12 h and chromium ion concentration of 30 mg L-1. The results demonstrated that the MBF produced from GY03 could be used in the chromium-containing wastewater treatment. Meanwhile, after extraction and analysis of the MBF polysaccharides, it was found that MBF was mainly composed of glycoprotein. Analysis on constituents of monosaccharide showed that polysaccharides of B. mucilaginosus were composed of rhamnose, glucose etc. Thus, because it was applied over a wide range of pH, in small amounts and had a rapid flocculation speed the flocculant used in this experiment had a vast field of application potential.

Numerical Simulation of Erosion-Corrosion in the Liquid-Solid Two-Phase Flow

Erosion-corrosion of liquid-solid two-phase flow occurring in a pipe with sudden expansion in cross-section is numerically simulated in this paper. The global model for erosion-corrosion process includes three main components: the liquid-solid two-phase flow model, erosion model and corrosion model. The Eulerian-Lagrangian approach is used to simulate liquid-solid two-phase flow, while the stochastic trajectory model was adopted to obtain properties of particle phase. Two-way coupling effect between the fluid and the particle phase is considered in the model. The accuracy of the models is tested by the data in the reference. The comparison shows that the model is basically correct and feasible.

Preparation of Composite Charge-mosaic Hollow Fiber Membrane by Interfacial Polymerization

The preparation of composite charge-mosaic membrane included spinning of hollow fiber as the supporting membrane, preparing a selective layer on the inside surface of the fiber by interfacial polymerization. The charge-mosaic membranes show a high salt permeability while retaining sucrose. The charge-mosaic membrane can be effectively used to separate multivalent salts with organic matter of molecular weight great than 300 g/mol in industry.

Effects of diphosphonic acid on ilmenorutile collecting property and research of action mechanism

The effects of several collectors and their dosage on pure ilmenorutile atdifferent pH values were studied and the collecting strength of several representative collectorswas investigated. The experimental results indicate that diphosphonic acid is a good collector forilmenorutile and the recovery of ilmenorutile ranges from 90.87 percent to 91.70 percent when thepulp pH value is 2.0-4.0 and the dosage is 75 mg/L. The sequence of collecting ability for severalcollectors is as follows: diphosphonic acid> TF279 > cyclic allryl hydroximic acid > benzyl arsenicacid> salicylic hydroximic acid> alkyl hydroximic acid. Meanwhile, IAS (infrared absorptionspectrum) and XPS (X-ray photoelectron spectroscopy) were used to detect and analyze the actionmechanism of diphosphonic acid on ilmenorutile. IAS results showed that the characteristicabsorption peak relating to P=O as well as P-O vibration occurred between wave numeber 1140 and 1032cm^(-1), and diphosphonic acid had adsorbed on the surface of ilmenorutile. XPS results indicatedthat the binding energy of P2P peak of ilmenorutile had changed 0.45 eV after treated bydiphosphonic acid. This proves that the adsorption is mainly chemical adsorption.

The Thermal Decomposition Mechanism and the Quantum Chemical Calculation of[Mg（H2O）6]（NTO）2·2H2O

[Mg(H2O)6](NTO)2·2H2O Was prepared by adding magnesium carbonate hydroxide to the aqueous solution of 3-nitro-1，2，4-triazol-5-one(NTO)．Its thermal decomposition mechanism was studied by DSC，TG／DTGand IR．The quantum chemical calculation on the title complex as a structure unit with the experimental geometry as atartmg values was carried out at B3LYP level with 6-31G basis set．The results show that the bonds between the coordinate waters and the Mgatom have certain extent covalent character．The net charges on nitrogen atoms of the NTO ring appear to be negative while the nitrogen atom on the nitro group(—NO2)appears to be positive which indicates—NO2 will lost first when the complex is heated to some uniform temperature and this result is in agreement with that of the thermal decomposition experiment．

Application of Catalytic Wet Air Oxidation to Treatment of Landfill Leachate on Co/Bi Catalyst

Catalytic wet air oxidation(CWAO) was employed to reduce the organic compounds in landfill leachate and the effects of temperature, oxygen pressure, catalyst dosage, and concentration of the organic compounds on the TOC and COD Cr removal rates were studied. The degradation kinetics of landfill leachate was also investigated and an exponential experiential model consisting of four influential factors was established to describe the reduction of the organic compounds in the landfill leachate. Meanwhile, the GC-MS technique was used to detect the components of the organic intermediates for the inference of the decomposition mechanisms of the organic compounds in landfill leachate. The results reveal that the reaction temperature and the catalyst dosage are the most important factors affecting the degradation reaction of the organic compounds and that the principal intermediates confirmed by GC-MS are organic acids at a percentage of more than 88% with no aldehydes or alcohols detected. The decomposition mechanisms of the organic compounds in landfill leachate were inferred based on the GC-MS information as follows: the activated gas phase O 2 captured the hydrogen of the organic pollutants to produce free radicals, which then initiated the catalytic reaction. So most of the organic compounds were oxidized into CO 2 and H 2O ultimately. In general, catalytic wet air oxidation over catalyst Co 3O 4/Bi 2O 3 was a very promising technique for the treatment of landfill leachate.

The Synthesis of Third-order Optical Nonlinear Organic Polyheterocyclic Materials

Synthesis of the third-order nonlinear materials: bis (1,4-dihydroxynaphthalene) tetrathiafulvalene and bis (1,4-dialkoxylnaphthalene) tetrathiafulvalene has been achieved in four steps, starting from 2,3-dichloro-1,4-naphthaquinone. The materials exhibit larger third-order nonlinear optical susceptibilities c(3) .

N,N-Dilauryl Chitosan: Synthesis and Surface Pressure-area Isotherm

With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, 1H NMR and elemental analyses. The results indicate that the average degree of alkyl group substitution on the chitosan increases with decreasing the molecular weight of the chitosan. The fully N,N-dilaurylated chitosan was found to be dissolvable in chloroform. The collapsed pressures of the samples derived from chitosan with 3000, 5000 and 10000 dalton are 47.6, 48.2 and 51.0 mN/m, respectively. The surface area occupied by the monomer unit(glucosamine) of all those samples is 0.6 nm2.

Intrinsic Kinetics of Dimethyl Ether Synthesis from Syngas

The intrinsic kinetics of dimethyl ether (DME) synthesis from syngas over amethanol synthesis catalyst mixed with methanol dehydration catalyst has been investigated in atubular integral reactor at 3-7 MPa and 220-260℃. The three reactions including methanol synthesisfrom CO and H_2, CO_2 and H_2, and methanol dehydration were chosen as the independent reactions.The L-H kinetic model was presented for dimethyl ether synthesis and the parameters of the modelwere obtained by using simplex method combined with genetic algorithm. The model is reliableaccording to statistical analysis and residual error analysis. The synergy effect of the reactionsover the bifunctional catalyst was compared with the effect for methanol synthesis catalyst underthe same conditions based on the model. The effects of syngas containing Na on the reactions werealso simulated.

The Chemical Speciation and Behavior of Mercury and Selenium in the Insoluble Fraction of Striped Dolphin Liver

Most of the mercury and selenium exist in the insoluble fraction of dolphin liver. After the insoluble fraction was digested by alkaline protease in the presence of 1%SDS, approximately 50% of Hg and Se consisted in the supernatant and the others in the residue. Gel filtration chromatography of the hydrolysate showed that 96% of Hg and 87% of Se were combined with the high molecular weight proteins stably, which cannot be substituted by the complex reagents. Mercury and selenium in the residue were confirmed as HgSe crystal.

Local Gas Phase Flow Characteristics of a Gas-Liquid-Solid Three-Phase Reversed Flow Jet Loop Reactor

The local gas-phase flow characteristics such as local gas holdup (εg), local bubble velocity (Vb) and local bubble mean diameter(db) at a specified point in a gas-liquid-solid three-phase reversed flow jet loop reactor was experimentally investigated by a five-point conductivity probe. The effects of gas jet flow rate, liquid jet flow rate, solid loading, nozzle diameter and axial position on the local εg,Vb and db profiles were discussed. The presence of solids at low solid concentrations not only increased the local εg and Vb, but also decreased the local db. The optimum solid olading for the maximum local εg and Vb together with the minimum local db was 0.16×10^-3m^3, corresponding to a solid volume fraction,εS=2.5%.

Study of The Pd-B/γ-Al_2O_3 Amorphous Alloy Catalyst

The Pd-B/g-Al2O3 amorphous alloy catalyst and Pd/g-Al2O3 crystalline metal catalyst were prepared by KBH4 reduction and routine impregnation, respectively. Pd-B/g-Al2O3 and Pd/g-Al2O3 catalysts were characterized by XRD and SEM. It was found that the catalytic activity of the Pd-B/g-Al2O3 amorphous alloy catalyst was higher than that of the Pd/g-Al2O3 crystalline metal catalyst in the anthraquinone hydrogenation.

The Adsorption of NO_X on Magnesium Aluminium Hydrotalcite

Magnesium aluminium hydrotalcite (Mg-Al-HT) with molar ratio of Mg-to-Al of 3 to l was prepared and characterized by X-ray diffraction (XRD) and infrared spectra (IR). The performances of Mg-Al-HT for the adsorption and desorption of NOx were studied. The results indicated that the adsorption capacity of the hydrotalcite for NOx was 1398.2 mg/g, and it was higher than the acticarbon's. The adsorption capacities depended on adsorption time and temperature. Mg-Al-HT could be regenerated by thermal decomposition, and the adsorption efficiency had not changed markedly after three cycles.

Necessary and Sufficient Conditions for Reactive Azeotropes in Multi-reaction Mixtures in Terms of Elemental Composition

Necessary and sufficient conditions for azeotropy in reactive mixtures axe derived in terms of elemental composition, which shows that in the space of elemental compositions, they take the same functional form as the conditions for azeotropy in non-reactive mixtures. The production of methyl tert-butyl ether (MTBE) is taken as an example. It is found that there are a 'pseudo' intermediate-boiling ternary reactive azeotrope at p=101.325 kPa and two 'real' ternary reactive azeotropes at p=101.325 Pa. The introduced elemental compositions also reduce the dimensionality of the phase diagrams and provide a natural set of variables for visualization of phase behavior.

Electrochemical Determination of Alkaline Phosphatase in Human Serum by Differential Pulse Voltammetry

Differential pulse voltammetry(DPV) was applied to the determination of alkaline phosphatase(ALP) activity in human serum with phenyl phosphate as the substrate. Phenyl phosphate can enzymatically be hydrolyzed to produce phenol which is quantified by DPV at +660 mV(vs.Ag/AgCl) in the concentration range of 2.0_100 μmol/L. The standard curve for ALP is linear over the range from 0.06 to 1000 U/L with a relative standard deviation of 3.0%. The conditions for the enzymatic reaction and voltammetric detection were optimized and the kinetic constants were also examined.The human serum samples were tested by this method and the results were in good agreement with those obtained by the routine p-nitrophenyl phosphate spectrophotometric method.

CATALYTIC PROPERTIES OF POLYMER-STABILIZED COLLOIDAL METAL NANOPARTICLES SYNTHESIZED BY MICROWAVE IRRADIATION

Catalytic properties of polymer-stabilized colloidal metal nanoparticles synthesized by microwave irradiationwere studied in the selective hydrogenation of unsaturated aldehydes,o-chloronitrobenzene and the hydrogenationof alkenes.The results show that nanosized metal particles synthesized by microwave irradiation have similar catalyticperformance in selective hydrogenation of unsaturated aldehydes,better selectivity to o-chloroaniline in hydrogenation ofo-chloronitrobenzene and higher catalytic activities in hydrogenation of alkenes,compared with metal clusters prepared byconventional heating.The same apparent activation energy(E_a=29 kJ mol^(-(?)) for hydrogenation of (?)-heptene catalyzed withplatinum nanoparticles prepared by both heating modes implied that the reaction followed the same mechanism.

Elemental Composition Method in Thermodynamics of Multireaction Systems (Ⅱ) Residual Properties,Property Changes of Mixing and Excess Properties Relations

Based on the concept of “element” and the fundamental thermodynamic principle,the relationships of the residual properties,the property changes of mixing,excess properties,fugacity coefficients and activity coefficients between the hypothetical solution of elemental species and the equilibrated solution of actual species were established.The hypothetical solution of elemental species provides a way of reducing the dimensionality of problem, simplifying the analysis and visualizing the phase behavior.

An investigation of the preparation of coal tar- and petroleum-based pitch spheres and their oxidation stabilization

Oxidation-stabilized pitch spheres were prepared from pitch spheres, which were obtained by emulsifying spheroidizing mixtures of aromatic additive, such as naphthalene, and high soft-point pitch from coal and petroleum. Thermogravimetric analysis, differential gravimetric and differential scanning calorimetric analysis were employed to investigate the stabilization behavior of pitch spheres in air in relation to the type of pitch, ratios of aromatic additive to high soft-point pitch, and structures of pitch spheres. It is found that an aromatic additive can greatly reduce the softening point of pitch and promote stabilization.Petroleum pitch based spheres are more liable to oxidation compared to coal tar pitch based ones. The oxidized surface of pitch spheres acts as a diffusion barrier that inhibits the oxidation stabilization, which is alleviated by increasing the amount of aromatic additive.