Advanced Materials Research Vol. 1088

Abstract: The methods and principle of industrial cutting fluid wastewater treatment in recent years was summarized in this paper and its research status quo, and the cutting waste water treatment was prospected.

Abstract: Antimony and arsenic are recognized to be toxic carcinogens. With the development of chemical industry, antimony and arsenic pollution problems are becoming more and more serious in soil. This paper described speciation analysis of antimony and arsenic in soil in the latest technical progress. Speciation analysis of arsenic and antimony which use joint techniques and non joint techniques are summarized. This paper also introduced various remediation technologies for antimony and arsenic contaminated soil. Finally, the trend for future technical development in remediation of antimony and arsenic in contaminated soils and speciation analysis is prospected.

Abstract: In this paper, environmental friendly phenol formaldehyde modified with larch thanaka and urea was used to make 2-ply bamboo laminated lumber. Effects of two assemble patterns (inner to inner and outer to outer) on physical and mechanical properties of 2-ply bamboo laminated lumber from carbonized and bleached bamboo strips were investigated. The results showed that modulus of elasticity (MOE) and modulus of rupture (MOR) of carbonized bamboo laminated lumber were better than that of bleached bamboo laminate lumber. It illustrated that physical and mechanical properties of carbonized bamboo laminated lumber became better. The MOE and MOR of bamboo laminated lumber, bonding with inner (low density surface) to inner surface, were better than that of outer (high density surface) to outer surface. It meant that MOE and MOR of bamboo laminated lumber were increased by the bonding surface density decreased of bamboo unit. Thickness swelling of carbonized bamboo laminated lumber was lower than that of bleached bamboo, which meant its dimensional stability was better than that of bleached bamboo laminated lumber.

Abstract: The influence of different carbon sources such as glucose, sodium acetate, sodium propionate and ethanol for polyhydroxyalkanoates (PHA) storage were studied in details. It was shown that both the cell content and composition of PHA synthesized by microorganisms in activated sludge were different when different carbon sources were used. PHB (polyhydroxybutyrate) was the main PHA if sodium acetate was used as carbon source, while PHV (polydroxyvalerate) become the main PHA when sodium propionate was used. Sodium acetate and sodium propionate as carbon source had higher PHA production, which reached to 40.89% and 40.96% sludge dry weight, respectively . When ethanol used as carbon source, PHA content was 25.69% sludge dry weight. The minimal PHA storage was 20.14% sludge dry weight when glucose was used.

Abstract: In order to search for an effective adsorbent on ammonia-nitrogen, a comparative study has been conducted on bentonite, zeolite and fly ash, which have been modified by hydrochloric acid, sodium hydroxide，sodium chloride and thermal to reveal ammonia nitrogen removal efficiency, respectively. The results showed that the modified zeolite of sodium chloride was an ideal adsorbent. The adsorption mechanism of sodium chloride-modified adsorbent was demonstrated via the Scanning Electron Microscope(SEM) analyses and relative theories. The removal percentage of ammonia-nitrogen could be as high as 88.34 % when the dosage of initial ammonia-nitrogen was 30 mg/L, the pH value was 8, the stirring intensity was 150 r/min, the dosage of modified zeolite was 20 g/L and the adsorption time was 120 min, which increased by 20 % than unmodified zeolite. The adsorption of sodium chloride-modified zeolite to ammonia-nitrogen is a superior adsorbent.

Abstract: This research aimed to present an alternative methodology to determine the tensile modulus of elasticity based on the least squares method, allowing multiple uses of load and displacements values obtained from the experiment, giving greater reliability in the calculation of timber stiffness. Were used twelve specimens of Eucalyptus grandis wood species, tested in tensile parallel to the grain according to the assumptions of the Brazilian standard ABNT NBR 7190:1997. The modulus of elasticity obtained from the proposed calculation approaches were compared with the elastic moduli obtained from Brazilian standard recommendations. Results of analyzes of variance (Kruskal-Wallis) showed statistical equivalence between the modulus of elasticity obtained for both forms of calculation. However, considering the non-homogeneity of wood, to generalize the conclusions, it is necessary new set tests involving all strength classes indicate by NBR 7190:1997.

Abstract: Shrinkage performance of alkaline residue concrete is researched in different conditions, it found that different alkaline residue proportions concrete dry shrinkage increases with the growth of the curing time increasing, but the dry shrinkage changes of different alkaline residue proportions are different, the dry shrinkage of low proportions of 8-12% concrete is similar with that of plain concrete, therefore, to the high content of concrete, its dry shrinkage significantly increase. The dry shrinkage of low incorporation proportion (8-12%) concrete increases quickly in the initial curing period (3-7 days), its shrinkage rate changes stabilized in the subsequent conservation period; to high incorporation proportion (20-30%) concrete, its dry shrinkage increases rapidly in the curing period of 7-14 days, then it stabilized. compared with the low proportion of concrete, its growth is faster in the late curing period. Water-cement ratio is very important factor of the shrinkage performance of concrete, dry shrinkage curve of alkaline residue concrete present concave, when water-cement ratio are in 0.52-0.57, the shrinkage of alkaline residue concrete is minimum.

Abstract: The microstructure of complex binder pastes was investigated by means of XRD and SEM-EDS. The results show that adding fly ash means decline of cement content in cementitious materials, which leads to the decrease of Ca (OH)₂ content in complex binder pastes. The Ca (OH)₂ crystal still exists in the complex binder pastes at the age of 360 days. By replacing part of cement with fly ash, the early microstructure of complex binder pastes becomes loosened. With the extension of curing ages, a great quantity of low CaO/SiO₂ ratio of C-S-H gel is generated, which makes complex binder pastes compact gradually.

Abstract: Pyrolysis behavior of a new kind of polybenzoxazine with aldehyde groups was investigated by pyrolysis gas chromatography-mass spectroscopy (PyGC-MS) at the temperatures ranging from 450°C to 750°C. It was found from the pyrolysis chromatograms that the type and amount of its pyrolysates obviously change with pyrolysis temperature due to various pyrolysis behaviors at different temperatures. From the structures and relative contents of the pyrolysates, the pyrolysis mechanism of the polybenzoxazine was described as follows: the initial degradation reactions occurred mainly at the C_methylene-N bond, followed by the C_phenyl-C _methylene bonds.

Abstract: A new inorganic nonmetallic cementing material rather than epoxy resin was adopted in carbon fiber sheet (CFS) strengthened concrete beams and slabs in this paper. Firstly, the types of inorganic adhesive were introduced and double-shear tests and the compressive strength of specimens as a function of temperature were studied to prove the effectiveness of inorganic adhesive in CFS strengthened concrete beams and slabs was studied. The practice shows that MPB has good performance when applying at high temperature. RC beams and slabs strengthened with new inorganic adhesives sticked FRP sheets are feasible. The appearance of MPB renders an extensive prospect for carbon fiber sheet (CFS) application in building structure reinforcement.