Advanced Materials Research Vols. 512-515

Abstract: The photochemical reduction of Cr(VI) in aqueous solutions containing Fe(III)-lactate complex was preliminarily investigated. The effects of initial pH, initial concentrations of Fe (III), lactate and Cr(VI) were studied in detail and the photoreduction mechanism of Cr(VI) was discussed preliminarily. The results indicate that Cr(VI) can be effectively photochemically reduced by Fe(III)-lactate complex, and the optimum pH for photoreduction of Cr(VI) is 3.0. The reduction efficiency of Cr(VI) decreases with increase of the initial concentrations of Cr(VI) over the range of 12.0~48.0 μM. The initial rate of Cr (VI) photoreduction increases with increase of the initial concentrations of Fe (III) or lactate. The photoreduction reaction is accordance with the law of apparent first-order dynamics reaction.

Abstract: Generally, the welding HAZ is more sensitive to corrosion. In order to increase the corrosion resistance of the welding HAZ in aircraft structures, the laser surface treatment technology was used to treat the welding HAZ. In this study, the processing parameters of the laser surface treatment were optimized. According to our study, the laser quenching can increase the corrosion resistance property obviously. The laser surface treatment new technique has been used in the maintenance of the airplane structures, which has better application outlook.

Abstract: In this thesis, potassium feldspar - NaOH reaction system under hydrothermal conditions was established. The aims of this research were to discuss comprehensively the factors affecting potassium dissolution rate of the system. The experimental result indicated: effect on the extracting rate of potassium, NaOH concentration > the reaction temperature > reaction time; The rate of extracting potassium can be up to 70% under the optimal conditions; XRD phase analysis of ore and slag filtering showed that NaOH additive destroyed the crystal structure of potassium feldspar, and formed a new phase.

Abstract: N,N-dimethyl-N’-(2-trifluorometyl-1-pentafluoroethyl) perfluoropropenyl propane diamine (I) was prepared by the reaction of hexafluoropropene dimer and N,N-dimethyl propylene diamine with the molar ratio 1:1.0 at about 35oC for 8h, and the structure of I was identified by IR and NMR spectra. Then I reacted with bromoethlane, bromopropane, bromobutane, bromohexane, bromooctane and bromolaurane to get a series of quaternary ammonium cationic fluoro-surfactants, and their structures had been measured by means of IR and NMR spectra. The results show that the novel fluoro-containing quaternary ammoniums cationic surfactants have excellent surface tensions, such as 17.8, 22.9, 23.8, 21.5, 25.5 and 28.1mN/m; much low cmcs for 2.03, 1.98, 1.93, 1.83, 1.74 and 1.58mmol/L. And their Krafft points are below 0oC, show execllent water-soluble.

Abstract: Cu2+-imprinted polymers (Cu(II)–IIPs) were prepared by thermal precipitation polymerization method with Cu2+ion as the template, 1,4-dihydroxyanthraquinone (AQ) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker. In synthesis processes,The functional monomer AQ, there is only one functional groups that can selectively recognize Cu2+ ion, is set in highly cross-linked polymer net, not to form covalent-linkage with polymer net. The imprinted polymer particles were characterized by UV-visible spectra, FT-IR, scanning electron microscopy and colorimetry. The sorption and selectivity capacity of Cu(II)–IIPs for Cu2+ ion were studied．The results showed that the imprinted polymer had good affinity for Cu2+. The maximum sorption capacity was 11.4 mg/g．The sorption equilibrium time was 50 min and the optimum pH for quantitative copper retention was 7.0. Competitive sorption of Cu2+, Co2+, Zn2+, Mg2+, Ca2+ from their mixture was also studied in a batch system. The relatively selective factor of copper to other metal ions were greater than 1. The Cu(II)–IIPs could be repeatedly used with high selectivity and stability for Cu2+.This Cu(II)–IIPs has been successfully applied to the separation and determination of the trace Cu2+ in real water samples.

Abstract: The effects of three kinds of red mud from alumina plant on limestone’s sulfation kinetics were investigated by thermogravimetric analysis method. Red mud can effectively improve the desulfurization performance of limestone in the whole temperature range. Red mud has little effect on the rate constant of the surface reaction (k), but it can significantly improve the effective diffusivity of reactant in the product layer (Ds). The enhancement of sulfation is more pronounced once the product layer has been formed and consequently the promoting effect becomes greater once the sulfation reaction becomes diffusion controlled.

Abstract: Energy balance and offgas utilization of ilmenite smelting in 30 MVA direct current electric arc furnace (DC furnace) of a Yunnan company were investigated to make sure safety production, and to save energy and reduce pollution. The total input energy in the DC furnace was 2,000 kWh per ton of ilmenite, in which 1,003.31 kWh per ton of ilmenite was used to carbothermic reduction and other energy was consumed as heatloss. Based on energy conservation, the whole system heatloss in physical production should be controlled at 1,000 kWh per ton of ilmenite. With high combustion heat, the offgas discharged from furnace after treatment could be used to ilmenite drying, anthracite drying, titanium slag drying, and casting ladle baking. The offgas design flow ranged from 5,000 to 8,000 Nm³/h with the mean of 6,500 Nm³/h. The combustion heat quantity of offgas in the plant was 82,160 MJ per hour, which could save 480,276.8 kWh of electrical energy per day, and thus lower carbon emission of the whole production line.

Abstract: The movement of aeration zone water is an important part of water cycle in natural. It promotes the precipitation, hydraulic contact of surface water and groundwater. But the change of the structure of vadose zone produce certain effect to its moisture movement, especially on reclaimed land is concerned, moisture in the air bag filling structure with sports have new features. This article through the indoor one dimensional vertical cylindrical tests, and the evaporation conditions with fly ash material 2 structure with water bag gas distribution, probes into the air bag with different profile of the moisture variation characteristics, analyzed the water movement, the mechanism of coal mine reclamation area for the field test, provides the basis.

Abstract: The sorption performance of tetracycline on zeolite under different conditions was investigated in presence and absence of Cu(Ⅱ).The presence of Cu(Ⅱ) greatly increased the adsorption of tetracycline on zeolite. Adsorption kinetics and adsorption equilibrium isotherms were studied by conducting series of batch experiments. The kinetic analysis indicated that the pseudo-second-order kinetic model was well described the sorption equilibrium process of tetracycline onto zeolite in the presence and absence of Cu(Ⅱ), and intra-particle diffusion was not the only rate-limiting in the sorption process. The qmax value calculated from Langmuir model were 17.37 and 68.26 mg/g in the absence and the presence of Cu(Ⅱ). The value of E calculated from Dubinin-Radushkevich (D-R) model confirmed that the adsorption in the absence and presence of Cu(Ⅱ) were mainly controlled by physical combined with chemical adsorption mechanism. The tetracycline sorption amount decreased in the absence of Cu(Ⅱ) and increased in the presence of Cu(Ⅱ) as the pH increasing. The adsorption removal rate of wastewater containing 0.1 mmol/L tetracycline was 95.5% in the presence of Cu(Ⅱ) and 34.5% in the absence of Cu(Ⅱ) when the dosage of zeolite was 0.05g.

Abstract: The hydrolysis of cinnamaldehyde in aqueous solution catalyzed by amino acids has been investigated. Eight amino acids e.g. glycine, proline etc. have been employed as the small molecular organocatalysts. The effect of reaction time, temperature, buffer concentration on the reaction has been studied. Spectroscopic analysis indicated the reaction product is 3-hydroxy-3-phenylpropanal.