Advanced Materials Research Vols. 306-307

Abstract: It was the first time to study the catalytic effect of mesoporous magnetic Fe₃O₄ nanoparticles on the biohydrogen production. The mixed culture used in this study just suffered from an alkaline shock and lost its bioactivity of hydrogen production. We use mesoporous Fe₃O₄ nanoparticles and ferrous ions as activators to recover the bioactivity of the mixed culture. The results indicate that the improvement of biohydrogen yield by mesoporous Fe₃O₄ was obvious larger than that by ferrous ions. The maximum yield of cumulative hydrogen production was obtained at the mesoporous Fe₃O₄ nanoparticles of 400 mg·L^-1, which is 26% higher than that of the blank. The lag phases for hydrogen production in the tests added with mesoporous Fe₃O₄ nanoparticles were decreased to 12 h, which are 50 h less than those of the corresponding ferrous ions and blank tests.

Abstract: The bio-oil, pyrolyzed in a vacuum fast pyrolysis reactor from larch sawdust, has high percentage of water (45%), low viscosity(9.80 mPa.s) and pH(2.75). The bio-oil sample was analyzed by GC/MS after filtered under vacuum conditions, which contains aldehydes(25.17%), ketons (5.56%), alcohols(11.35%), esters(4.46%), acids(6.54%) and phenols(20.99%). Two schemes, single stage extraction and multistage reflux extraction, were attempted to study the extraction efficiency of solvents, using cyclohexane, dichloromethane, ethyl acetate and butyl acetate. All the fractions were analyzed by GC. Of the four solvents, the efficiency of dichloromethane is highest, while cyclohexane basically has no use. Comparing with single stage extraction, the efficiency of multistage reflux extraction is as high as 1.5 to 3 times. Especially, yields of alcohols and acids, using dichloromethane, are respective 72.39% and 52.27%. However, there is a decline in the extraction for ketons and aldehydes, respectively using dichloromethane and ethyl acetate.

Abstract: The silane treatment is a new kind of metal surface treatment technique. Compared with the traditional chromate and phosphate treatment, organic silane treatment is friendly to environment. In this paper, the structure, classification and corrosion protection mechanism of silane films were introduced. The application and research progress of protective organic silane films were reviewed．The prospect of organic silane treatment technique was put forward．

Abstract: The blast furnace water quenched slag has characteristics such as porous and superficial roughness, so it can be modified and cranked out a filter media. The treatment efficiency of domestic sewage with water quenched slag biological aerated filter (BAF) was researched in this paper. And the removal rate of organic compound, ammonium, SS, and chroma was also investigated. The results showed that the quality indexes of the domestic sewage after treatment met the primary standard of the national integrated wastewater discharge standard (GB8978-1996). So the purpose of the waste harnessed by other waste is achieved. The applicative prospect of blast furnace water quenched slag on domestic sewage treatment is very broad.

Abstract: 1-dodecyl-3-methyl imidazolium chloride ([C₁₂mim]Cl) was adsorbed on iron surface to form an inhibitive film. The adlayer inhibited the metal corrosion in 0.2 M H₂SO₄ efficiently. The inhibitive effect of [C₁₂mim]Cl was characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Impedance spectra demonstrated that the values of charge-transfer resistance increased when adding [C₁₂mim]Cl into 0.2 M H₂SO₄. The inhibition efficiency increased with increasing the concentration of [C₁₂mim]Cl. Scanning electron microscopy (SEM) analysis showed that the corrosion of iron surface had been inhibited by [C₁₂mim]Cl.

Abstract: In order to reduce fluorine pollution, partial fluoride could be replaced by Li₂O in mould flux. The effects of Li₂O on properties of low fluoride content mould flux for high speed continuous casting were studied. The properties included melting temperature, viscosity, fluidity, surface tension and Al₂O₃ inclusion adsorption. The results showed that with the increase of Li₂O content, melting temperature and viscosity of mould flux decreased obviously, fluidity increased, surface tension changed little, and Al₂O₃ inclusion adsorption of mould flux increased. In order to play an effective role, the appropriate Li2O content should be less than 4 per cent. The crystallization state of mould flux changed after slag adsorbed Al₂O₃. There were some small cuspidine and wollastonite crystals in the sample.

Abstract: The effects of kaolin on the properties of flue gas desulphurization gypsum-based steel slag composites were analyzed in this article and the influence rules of setting time, final setting time on the flexural strength and compressive strength of cementitious composites were also discussed. The micro-morphology of the composite was observed by scanning electron microscope. At the same time, the excitation mechanism of kaolin on gas desulphurization gypsum-based steel slag was put forward. It was demonstrated that kaolin with content of 3% in the composites can better stimulate the activity of steel slag and improve the mechanical properties of cementitious composites.

Abstract: The photolysis ability and adsorption ability of TiO₂ was detected and measured using acetaldehyde as a probe. The quantitative relationship between the TiO₂ deactivation and the concentration of the surface adsorbed SO₄^2- was obtained by intentional controls of the concentrations of the surface adsorbed SO₄^2-. When the concentration of the surface adsorbed SO₄^2- reached 2.0 wt%, the photolysis ability of the TiO₂ photocatalyst decreased by 50%, and when the concentration was 2.9 wt%, the TiO₂ adsorption ability decreased by 50%. 90% of the absorbed SO₄^2- can be removed after the samples have been washed by overflowing water for 2 hours at a rate of 2 L.min^-1 and the photocatalytic activity can be regenerated. This work will help to predict the lifetime of TiO₂ photocatalyst in actual applications as well as to understand its regenerations of the photocatalytic capability.

Abstract: Hydrophilic polyvinylidene fluoride (PVDF) flat ultrafiltration membranes were prepared by wet-spinning method. The effects of technical parameters of acrylic acid grafted onto PVDF on the performance of hydrophilic PVDF membranes were investigated, the technical parameters of preparation of hydrophilic PVDF membranes were determined, and hydrophilic PVDF flat membranes were prepared. Then, hydrophilic PVDF membranes were characterized in terms of pure water flux, contact angle, infrared spectroscopic analysis and scanning electron microscope (SEM). The results showed that acrylic acid had been grafted onto PVDF, and the hydrophilic performance of the modified membrane was better than the traditional one.

Abstract: Basing on basic properties of coal gangue from No.1 mine of Pingdingshan Tian’an coal group, authors made coal gangue concrete with coal gangue instead of some aggregate, fly ash and slag instead of some cement. Coal gangue concrete was studied by the method of orthogonal experiment. Compression strength, its loss of strength after corrosion by sulphate, modulus of elasticity and its loss after freeze-thaw were analyzed. Optimum mix of coal gangue concrete was given by the integrated balance method. And Finally, SEM analysis on coal gangue concrete was researched. According to the experiment, Sulfate attacking on coal gangue concrete was little.