Advanced Materials Research Vols. 396-398

Abstract: The selection of salting agents for extractive distillation of ethanol-water system through analyzing the vapor-liquid equilibrium (VLE)data was studied. Firstly, the atmospheric VLE data of the ethanol-water system were measured, and the reliability of the vapor-liquid equilibrium apparatus was tested by comparing the measured VLE data with those reposed in the literature and by checking their thermodynamic consistency.Secondly, the atmospheric VLE data of the Ethanol-water system with agents were measured, and also the changes in relative volatility and the selectivity were checked, so that the optimum agent lithium chloride was then selected. Finally, the impact of the lithium chloride concentration on VLE data of Ethanol-water system was studied.

Abstract: Surface charge properties of DL nanofiltration membrane were studied using streaming potential method. The results indicate that in the experimental concentration range, the relationship between NF membrane surface charge density and electrolyte solution concentration is in good agreement with Freundlich-isotherm adsorption, which indicates that the membrane surface charge comes from the adsorption of ions of the solution. In addition, the analysis of anion and cation adsorption on nanofiltration membrane surface showed that adsorption of common ions to the Inner Helmholtz Plane through specific adsorption increases the charge density, while adsorption of counter ions to the Outer Helmholtz Plane through electrostatic interactions leads to electric double-layer contracting inward, decreasing the membrane surface charge density.

Abstract: A hydrometallurgical process was used for selectively extraction of valuable metals from zinc plant residues. The process includes the following two steps. (1) The zinc plant residue is treated by sulfuric acid atmospheric leaching process with KMnO4 as oxidatant to selectively dissolve zinc while leaving most (above 98 pct) of indium and germandium in the iron residues. (2) The iron residues are treated by acidic atmospheric leaching process with NaClO3 as oxidant to dissolve indium and germanium. The valuable metals of indium and germanium in the second leaching solution can be reclaimed by further treatment. The optimum operating parameters of the first stage and the second stage were established by conditional tests. The experimental data indicated that under the conditions employed the zinc extraction in the first stage was above 95%, and the leaching percentage of indium and germanium in the second stage reached 91.6% and 90.7%, respectively.

Abstract: Esculeoside A, the tomato saponins from Lycopersicon esculentum MILL, may be metabolized into various steroidal hormones such as pregnane derivatives that are expected to exhibit various bioactivities in the body, such as anti-osteoporosis, antimenopausal disorder and anti-tumor actions. In order to enrich large amount of esculeoside A for further scientific research, we firstly developed a high performance liquid chromatography (HPLC) with evaporative light scattering detection (ELSD) method for its quantification, and used it to examined the content of esculeoside A in different cultivated varieties of tomato fruits and tomato extract. Statistical analysis of the obtained data demonstrated that our method was simple, and has achieved desired linearity, precision and accuracy. Then we have explored the feasibility of using pectinase as a means for assisting esculeoside A extraction from fresh tomato fruits, and several factors such as the enzyme concentration, pH value of enzyme solution, temperature, incubation time which influenced on extraction were investigated. Moreover, in our previous study, the adsorption characteristics on several types of macroporous resins have been compared. Among them, D-101 resin showed the best separation behaviors on esculeoside A. So in the present paper, in order to get the best parameters for D101 adsorption, the adsorption kinetic curve, the appropriate ethanol concentration for elution and breakthrough volume were analyzed．

Abstract: The creep character of anchor rod in argillaceous soft rock is remarkable. The big undisturbed mudstone samples in Nanning Basin as a typical argillaceous soft rock is chosen to the research object in this paper. The laboratory simulated destructive tests and the creep tests of full grouted anchor rod have been down. Through the destructive tests of mudstone sample, the instantaneous adhesive strength between the anchor body and mudstone in Nanning Basin is 70kPa. By analyzing the creep curves of anchor rod, a conclusion is that there is a long-term adhesive strength of anchor rod in argillaceous soft rock. When the design adhesive strength of anchor rod is less than the long-term adhesive strength, eventually the anchor rod is stable during the process of long-term pull-out. When the design adhesive strength of anchor rod is greater than the value, the creep of anchor rod with the time will do not stop until the anchor rod failure. The greater difference value between the instantaneous and long-term adhesive strength, the faster the rate of creep, the faster the anchor rod failure. Finally, for the permanent support engineering design of anchor rod in argillaceous soft rock, the paper gives two principles, as follows: (1) the design of anchor rod in argillaceous soft rock must be determined according to the long-term adhesive strength. (2) by using variety of technical measures, the impact of various factors on the creep of anchor rod will be decreased.

Abstract: The adsorption properties,including the adsorption isotherms,thermodynamics,of grape seed procyanidins onto macroporous resin HZ818 are investigated.Both the Langmuir and Freundlich equations can provide a good fit to the adsorption isotherms, which indicates an endothermic and a favorable process in our study.The capacities of the adsorption increase with temperature. The negative values of ΔG and values of ΔH lower than 40 kJ/mol indicate a spontaneous physical adsorption, and the positive values of ΔS show the increased randomness at the solid/solution interface during the adsorption process.

Abstract: The solid-liquid extraction kinetics of flavonoids from Ficus microcarpa with ethanol was studied. The effects of temperature and concentration of ethanol on extraction kinetics were examined. It is found that the higher temperature and concentration of ethanol, the higher leaching yields. The leaching process can be described by outer diffusion control model before 60 min and the shrinking-core model between 60 min and 150 min. The leaching process kinetics equations were established, respectively.

Abstract: A condensation separation model was designed to simulate and optimize the gasoline vapor condensation recovery systems in gas stations using Aspen Plus software. The relationship of either vapor recovery ratio or system energy consumption with condensation temperature was investigated. The results showed that the recovery system should be properly optimized into three-stage condensation processes. When the condensation temperatures at the three-stage were 2°C, -30°C and -80°C, respectively, the system recovery ratio would slightly exceed the national standard index of 95% of China and the system energy consumption could be almost controlled within the lowest level. Moreover, if the condensation temperature at the third stage was -120°C, the recovery ratio would be up to 99.62% and the energy consumption could be controlled in a little rising.

Abstract: The copolymers of polysulfone-graft-acrylic (PSF-g-PAAc) acid were synthesized by homogeneous photo-initiated graft copolymerization method. Variable affecting the degree of grafting (DG), such as the ultraviolet irradiation time, and the concentrations of the acrylic acid monomer and photoinitiator, were investigated. The graft copolymers were characterized by chemical titration, attenuated total reflection-Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy analysis. It is verified that acrylic acid groups were present on the polysulfone polymer. Then, membranes were prepared from the PSF-g-PAAc powder with different DG using phase inversion method. It is found that the flux properties of the membranes were dependent on the pH value of the aqueous solution.

Abstract: Experiments were carried out to study the adsorption kinetics of grape seed procyanidins onto macroporous resin HZ818 from aqueous solutions.The effects of temperature,initial concentration and agitation on the adsorption kinetics have been investigated.Both the Lagergren-first-order equation and intra-particular diffusion model were used to describe the adsorption mechanisms. And the adsorption process were affected both by film diffusion and by intra-particle diffusion.The intra-particle diffusion rate constants increase with an increase in temperature,initial concentration and agitation speed.