Advanced Materials Research Vols. 113-116

Abstract: Self-made pairs of pole-type magnetic separator using materials of NdFeB. Permanent high gradient magnetic separator do without excitation current, the equipment with low cost, low operating costs, and highlights the advantages of small floor space, etc. Using stainless steel nets as a poly-magnetic medium, we conducted a dry separation experimental study on high-sulfur coal of Pingdingshan G unit, focusing on the vibration frequency; number of sorting and pulverized coal size, and the effect on the separation. The results showed that: the increase in desulfurization rate and ash removal rate is based on the cost of losses of clean coal yield. When vibration frequency is 50HZ, the pulverized coal with 100-200 mesh through three times sorting, the desulfurization rate and ash removal rate is 28.02% and 22.43%, and the corresponding coal production rate is 80.79%.

Abstract: In order to make high performance wood-plastic composites (WPCs) from wood-fiber and mixed plastic wastes, virgin resins were compounded to simulate mixed plastic wastes, which included polypropylene, polyethylene and/or polystyrene, then grafted with maleic anhydride (MAH) by reactive extrusion. Highly filled WPCs were prepared by extruding. Mechanical testing results showed that the mechanical properties of the composites based on grafted virgin and waste plastics both significantly enhanced. The compatibility between the different plastics in the blend system and the interfacial adhesion between wood fibers and the blends were both improved with the modification of the blends, as evidenced by SEM. For the composites based on MAH grafted plastics, the water absorption and thickness swell decreased, which is true for the composite made from both virgin and recycled plastics. This blending-grafting modification method can be considered as a feasible approach to use mixed plastic wastes in the manufacture of high performance WPCs.

Abstract: This paper presented a new analytical model of partial differential equations (pde) for volatile organic compounds (vocs) emission from porous building materials. By applying Laplace transformation the representations for vocs concentration in the chamber and in the porous building material were given. The emission curves and average concentrations of some porous building materials Medium Density Fiberboards (mdf) in an airtight chamber were obtained. Result of the present model shows a good agreement with the experimental data.

Abstract: Phosphogypsum-lime-flyash-gravel mixture (PLFG) is usually used to strengthen road foundation of geotechnical engineering. It is important to correctly understand its compressive behavior before corresponding design. In this present paper, triaxial compression test on PLFG was carried out, and its stress-strain curve was investigated. Experiment data show that PLFG is with high bearing capacity and good stiffness. A new composite-exponent model was established, which is available for both hardening and softening type strain-stress curves of PLFG. Finally, comparison between PLFG tested data and new model simulation was performed, and good agreements have been found. This research is helpful for engineering sustainable utilization of phosphogypsum to bring economy and to reduce environmental pollution.

Abstract: The removal efficiencies of 4 air-cleaning materials on formaldehyde and VOC emissions from particleboards were examined in this paper. The effect of activated carbon and photo catalyst on formaldehyde and VOC emissions removal was notable in short time. The effect of scavenger was obviously on formaldehyde removal for its synthetic mechanism. And the impact of bioenzyme on formaldehyde and VOC emissions from particleboards is dependent on the test conditions and it shows no impact on emissions in this experiment.

Abstract: Particleboard has been indicated as one possible source of volatile organic compounds (VOCs) at normal indoor. This paper examines the VOCs emissions from the larch particleboards. Temperature, relative humidity and air change rate are significant factors influencing the VOCs emissions from particleboards. With the temperature and humidity various in the ranges from 23°C-40°C and 10%-70%RH the TVOC concentrations increased. Whereas the increasing of air change rate causes the TVOC concentration decreased.

Abstract: The performance of UV/TiO2 (100 mg/L TiO2) process for Orange II degrdation was emphatically compared at pH 2.3, 6.9 and 11.5 by means of UV-Visible spectra, ionic chromatography, TOC, and HPLC analyses. The results revealed that the reaction intermediates were produced in different contents with the increasing reaction time due to the different pH conditions. The dye was oxidized more completely at pH 2.3 while the highest color removal percentage was achieved at pH 11.5. It was proved that active electrons, which is photo-generated along with positive holes on TiO2, not only contribute to the discoloration and mineralization of the dye due to the producing of oxidative species such as O2•- and •OOH, but also contribute to the discoloration of Orange II as reductive species. The most possible mechanism was put forward to explain the key roles of active electrons in dye degradation by UV/TiO2 process at pH 2.3 and 11.5.

Abstract: An ethanol-based hydrogen producing bacteria Ethanoligenens R3 was isolated from continuous stirred tank reactor used for hydrogen production in previous experiment. Batch culture experiments were operated in this study with the fermentative temperature of 35°C and substrate concentration of 10g/L. The performance of hydrogen production from glucose, brown sugar and starch by Ethanoligenens R3 was investigated. The results show that the optimal substrate used for bio-hydrogen production was glucose with the maximum hydrogen yield of 834 mlH2/L culture. Furthermore, effect of initial pH of the culture medium on hydrogen production was studied. It is demonstrated that Ethanoligenens R3 reached the maximum biogas yield of 1760 ml/L culture with the maximum total VFAs concentration of 3329.39 mg/L at the initial pH of culture medium of 5.5.

Abstract: Anaerobic process of biohydrogen production is developed. The isolation and identification of high efficient biohydrogen production anaerobic bacteria is the important foundation of fermented biohydrogen production process by anaerobic digesting organic wastewater. Taking Considering with the physiological and biochemical traits, morphological characteristics and 16S rDNA sequence, the isolate NEFU-1 is a new species.

Abstract: Adsorption of ethane onto activated carbons derived from oil palm shell, bamboo and coconut shell, three abundantly-available agricultural solid wastes, by thermal or chemical activation method was investigated in this paper. Dynamic adsorption in a fixed bed configuration showed that the activated carbons prepared by chemical activation performed better than those by thermal activation. Desorption tests at the same temperature as adsorption (298K) and at an elevated temperature (473K) were carried out to confirm the occurrence of chemisorption on the activated carbons. Surface chemistries of the activated carbons were characterized by Fourier transform infrared spectroscopy and Boehm titration. It was found that uptaking ethane onto the biomass-based activated carbons was due to different mechanisms, e.g. physisorption, and/or chemisorption, depending on the activation agent and activation method.