Advanced Materials Research Vols. 476-478

Abstract: In this paper the adsorption properties of activated aluminum oxide (AAO ) to As(V) were researched. The effect of operating factors such as pH, contact time and initial As(V) concentration was investigated and the optimum operating conditions were established. Experimental results indicated that the optimal pH value adsorption of As(V)by activated aluminum oxide was from 4 to 6, and the optimum initial pH values was 5.5.The adsorption equilibrium was achieved within 5h.The adsorption capacity for As(V)increased with increasing concentration and the adsorption date was well fit by the Langmuir isotherm model. It is believed that activated aluminum oxide (AAO) is environmentally acceptable and industrially application for utilization in arsenic-containing wastewater treatment.

Abstract: Ethylenediamine (EDA) functionalized mesoporous MCM-41 particles displaying various functionalization levels have been prepared by one-pot method. The prepared samples were treated with Fe(III) to form cationic complexes inside MCM-41 pores (MCM-41-NN-Fe-x%, x=10, 20 and 30) for trapping phosphate from water. The prepared adsorbents were characterized by XRD, BET, TGA and elemental analysis, and their phosphate adsorption performances were studied. The results showed that the phosphate removal rate of all the prepared adsorbents were higher than 95% at the initial phosphate concentration of 2 ppm. Additionally, the Langmuir model was used to simulate the sorption equilibrium, and the results indicated that the experiment data agreed well with the Langmuir model. The maximum adsorption capacities calculated from the Langmuir model increased with the increase of diamino loadings in adsorbents, and the maximum adsorption capacities of MCM-41-NN-Fe-30% was 52.5 mg/g.

Abstract: This essay is the subject of national eleventh five support schemes: The analysis of key technology on emission reduction and comprehension utilization of solid waste from large iron ore mine (Number:2008BAB32B14).For the concrete with ultra-fine iron tailings the research on the new special cement has been successfully prepared by means of using a low dosage of crystal-core-element named CCE for short (which has an excellent capability to accelerate the hydration speed and develop the strength of the cement)and high percentage of blast furnace slag and other several industrial residue. Compared to the ordinary Portland cement grade 42.5, the new cement has several outstanding virtues such as lower use level of cement clinker, higher level usage of industrial residue and lower cost. According to the cement standard GB175-2007, strength of special cement sample NO.3 is same as the ordinary Portland cement grade 42.5 with the standard sand. When with ultra-fine iron tailings, the new special cement has higher strength after 28days than the OPC. That shows the special cement has an excellent long-term performance of concretion. The manufacturing cost of the new special cement sample NO.3 is decreased by 20.76% than the ordinary Portland cement grade 42.5, that will bring a great environment and economic effect.

Abstract: NaA / MCM-48 micro-mesoporous molecular sieve was prepared at 100°C for 72 h by hydrothermal synthesis method, where chemicals with a equivalent ratio of n (SiO2)∶n (CTAB)∶n (H2O)∶n ( NaOH) is 1∶0.45∶60∶0.48 were added to NaA microporous molecular sieve prepared hydrothermally at 100°C for 5 h from a composite solution with a equivalent ratio of Na2O∶SiO2∶Al2O3∶H2O is 3∶2∶1∶200. The adsorption of the NaA / MCM-48 micro-mesoporous molecular sieve to cationic red X-5GN simulated dye existing in the waste water showed that, in 50 mL of 20 mg/L cationic red X-5GN solution, under the optimal conditions of a dosage of NaA/MCM-48 micro-mesoporous composite molecular sieve of 1.8g/L, a pH of 7 and an oscillation time of 30min, the decoloration rate of spent solution was above 82.5%. The XRD, SEM and TEM processes were adopted for its characterization to display the possible reasons.

Abstract: Torque measuring in the extra-high rotation speed has not been resolved ideally yet, due to the restriction of the rough conditions. The dynamic characteristics of the developed digital plane grating angular-torquer measuring system are analyzed in this paper. The paper mainly calculates and designs the parameters of elastic shafts with different cross-section. Via the compare of dynamic characteristics and compactness of the elastic shafts with different cross-section, the optimized design is proposed at the end of the paper. The achievements of this paper can supply references to the study and design, maintaining and improvement of relative instruments.

Abstract: The damage and improvement mechanism of rebonded MgO-Cr2O3 brick and MgO-ZrO2 brick used in the lower part of RH vacuum degasser were studied. The results show that the main damage of rebonded MgO-Cr2O3 brick is structure spalling because of the penetration of slag. MgO-ZrO2 brick has characteristics of high direct-bonding degree, small air permeability and making the viscosity of penetrated slag increased by means of ZrO2 absorbing CaO in slag to form CaZrO3 or ZrO2 solid solution, which make the degree of slag penetration decrease and improve the structure spalling resistance. MgO-ZrO2 brick has the defect of poor thermal shock resistance in use, the incorporation of MgO-rich spinel into MgO-ZrO2 brick significantly improved both thermal shock resistance and hot modulus of rupture because of the formation of eutectoid structure of grain-refining spinel and zirconia, which also improved structure spalling resistance because air permeability was decreased to 5% of MgO-ZrO2 brick

Abstract: A new water-borne nontoxic emulsion of low cost was prepared by using wasted polystyrene foam as elementary component, butyl acrylate (BA), styrene (St) and vinyl acetate (VAc) as modifiers and solvents. Influences of monomers, compounded emulsifier on properties of emulsion were discussed. The optimum process conditions were as follows: m (PSF) : m (monomers) = 1 : 2 , m (sodium dodecyl sulphate) : m (OP-10) = 2 : 1 , m (VAc) : m (St) : m (BA) = 1 : 1 : 2 , and mass fraction of emulsifiers was 3.0 wt% accounting for the total mass of monomers. The synthetic latex with high adhesion strength, pollution-free, low cost and storage stability is applicable to prepare blast furnace slag unburnt bricks, respectively. The properties of the brick sample are better than that of MU 25 of GB 11945-89.

Abstract: The Fe3+-doped nano-TiO2 catalyst with various amounts of dopant Fe3+ irons was prepared by a sol-gel method. The products were characterized by XRD and SEM. The photocatalytic degradation of ammonia nitrogen in aquaculture wastewater was investigated by using Fe3+-doped nano-TiO2 under UV irradiation. In the experiment, the effect of Fe3+/TiO2 dosage, the ratio of dopant Fe3+, ammonia-N initial concentration, pH value, H2O2 volume concentration, and reaction time, respectively, on the removal of ammonia-N was investigated. The experimental results can be stated as follows: when the ratio of dopant Fe3+ was 0.25% wt, the dosage of Fe3+/TiO2 was 0.7 g/L, the initial concentration of ammonia-N was 10 mg/L, H2O2 volume fraction was 4 %, respectively, if the reaction time may last 4 h, the removal rate of ammonia-N was expected to reach 97.17 %.

Abstract: Environmental friendly materials, K₆SiW₁₁O₃₉Sn^Ⅱ(abbreviated as SiWSn), was synthesized, which is visible light response photocatalyst. The photocatalytic decomposition of Acid Brilliant Scarlet (abbreviated as ABS) aqueous solution with SiWSn was investigated using a broad spectrum of solar radiation. The results showed that the photocatalytic degradation efficiency of ABS with SiWSn was affected by the initial pH of ABS solution, the amount of SiWSn and the photolysis time. When the initial pH of ABS solution was 5, the initial concentration of that (20mL) was 3mg L^-1, the concentration of SiWSn was 1.25g L^-1, and it was irradiated 4h under the sunlight, the discoloration rate of which was 71.4%.

Abstract: This study investigates self-compacting glass concrete(SCGC), which was used at water-to-binder ratios (w/b) of 0.28, with four kinds of glass sand replaced at various volume replacement ratios (0%, 10%, 20%, and 30%). Fly ash, blast furnace slag and superplasticizer were also added to research the engineering properties of concrete. With increasing amounts of replacement up to 30%, results show that: (1) slump flow and V-funnel time are increased; (2) 340 mm is passed at 0min, and the filling level is elevated at 45 min; (3) the compressive strength of SCGC aged 28 days at various replacement ratios rises up to 60 MPa. The ultrasonic pulse velocity and electrical resistance are also enhanced with increasing age and replacement. After 56 days, the electric resistivity is higher than 20 KΩ-cm, and the shrinkage of SCGC falls within 0.2%. This study suggests than SCGC has superior engineering properties. A mechanism for LCD optical waste glass usage can be established to achieve industrial waste minimization, resource recycling, and economic security