Advanced Materials Research Vols. 356-360

Abstract: In this paper, cobalt oxide was deposited on the surface of Activated Carbon Fiber (ACF) by adsorption and was then sintered. The effects of cobalt oxide on the properties of ACF were studied by XPS, FTIR, and XRD methods. Mercury removal performance was also investigated. 5% cobalt was well dispersed on the surface of ACF, and a variety of oxygen-containing groups had been enhanced. The chemical functional groups on the surface of ACF were changed to strengthen the adsorption and catalytic oxidation of ACF to the element mercury (Hg⁰). The measurement results showed that ACF coated with cobalt oxide had higher adsorption properties.

Abstract: The expanded graphite coated with different portions of Fe₃O₄ nanoparticles (EG/ Fe₃O₄) were synthesized by a simple hydrothermal reaction and the composite was characterized by scanning electron micrograph (SEM), X-ray diffraction (XRD) and infrared spectroscopy (IR). The catalytic performance of the composite was studied through the degradation of methylene blue. The results indicated that a complete and uniform Fe₃O₄ nanoparticles coating on expanded graphite could be obtained under routine pressure and temperature and the optimum content of Fe₃O₄ in the composite was 6wt% in the experiment of catalytic degradation of methylene blue.

Abstract: Hollow cubic TiO₂ particles were synthesized using cubic Cu₂O particles as hard templates, and the hydrolysis of tetrabutyl titanate (TBOT). The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Vis spectrometer, respectively. The results show that the prepared TiO₂ is composed of anatase TiO ₂, and has a stronger absorption in the range of 300-400nm wavelengths in its UV-Vis spectroscopy. Experiments were carried out using a methyl orange solution as a model to evaluate the photocatalytic activity of hollow cubic TiO₂ particles. The effects of catalyst dosage, initial concentration and pH of methyl orange solution on the degree of photodegradation have been investigated. It’s found that the hollow cubic TiO₂ particles have a good photocatalytic property. And the degradation rate of the methyl orange, after methyl orange solution (5mg/L) containing hollow cubic TiO₂ particles (0.5g/L) is irradiated by 125W ultraviolet light for 120 minutes, is 95%.

Abstract: Pure ZnO and SnO₂-ZnO nanofibers were synthesized by electrospinning method and characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and methanol sensing properties of these fibers were investigated. The results indicate that the 20 wt% SnO₂-ZnO sensor exhibits considerable sensitivity, rapid response, and good selectivity against methanol at 200 °C due to the special 1D fibers properties and the promoting effect of SnO₂/ZnO heterojunction structure. The methanol sensing mechanism of SnO₂ -ZnO nanofibers were also discussed.

Abstract: The water quality and treatment process of two water plants in Jinan city were studied to evaluate the safety of urban water supply. The water qualities of two water plants were studied investigating the total numbers of colony, turbidity, oxygen consumption, free chlorine, pH, and water temperature. The correlation of the two water plants was all below 0.5 and the max of dissolved oxygen in the raw water of two water plants were 12.46mg/l, 12.31mg/l respectively. These result showed that water quality mainly depend on the raw water and treatment process.

Abstract: Nanometer titanium dioxide films supported on glass, quartz, molybdenum, and aluminum were prepared by sol-gel method. The loaded titanium dioxide films were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and photocatalytic degradation of aqueous crystal violet. The titanium dioxide films supported on different substrates were all composed of polycrystalline nanoparticles, which belonged to single-phase anatase, and displayed different morphology after sintering at 773 K for 1 h. Some elements in the substrate made of noncrystal appeared on the surface of titanium dioxide films. The experiment about basic crystal violet degradation displayed the photocatalysis activity of titanium oxide films supported on the molybdenum was better.

Abstract: Isophthalonitrile(IPN) used in this study contains two cyano groups(-CN) attached to the m-benzene ring. The IPN wastewater is degraded by biological method of high efficiently coupling microorganism. The choice of carrier is the key factor of immobilized biological technology. Two immobilization methods, adsorption with ceramic as the carrier，embedding with Sodium Alginate(SA) and Polyvinyl Alcohol –Sodium Alginate(PVA-SA) as the carrier, the research is conducted into the degradation effects. Results showed that IPN biodegradation by adsorption method had the best effect degrading. The IPN degradation rate kept stable and was over 96%. Additionally, in order to demonstrate purification of the IPN wastewater. The laboratory-scale experiment was carried out in a biological aerated filter (BAF) that was filled with ceramic filler. Results also showed that the BAF reactor removed the IPN and the rate was over 95%.

Abstract: Ground-level ozone pollution has attracted attention from academia and public in China recent years. This paper examines the effect and benefit of controlling ground-level ozone pollution in Beijing and its surrounding areas based on health effect valuation and cost-benefit analysis. It compares pollution damage effects under current ozone concentration and six assuming control targets then estimates the health benefit of air quality improvement by cost-benefit analysis. The result shows that, the benefit of ground-level ozone control is considerably huge for the high population density and pollution concentration area which implies the ground-level ozone pollution control policy implementation is necessary and urgent.

Abstract: This study investigated the levels of eight metallic elements in groundwater of 15 tap water treatment plants (TWTPs) located in the North of Jiangsu Province, China during 2007–2009, and evaluated the non-carcinogenic risks posed by the metals. Among the metals, Zn had the highest concentration (105.3 μg L⁻¹), while Pb contributed most (40.3%) to the average hazard index (HI) of 15 TWTPs, followed by Cd (33.8%) and Mn (12.2%). Each metal, except Pb, had an average concentration below the permissible limit of China, WHO, EU and USA. Both hazard quotients of individual metals and HI of total non-carcinogenic risk in each TWTP were lower than 1, indicating that these pollutants provided negligible public health risk for local residents. Non-carcinogenic risks induced by metals showed temporal and spatial variations, revealing that low HIs occurred more frequently in high water seasons, and the three TWTPs of Xinan, Suqian and Biantang had relatively higher HIs.

Abstract: This paper presented a numerical evaluation of the lightning electromagnetic environment inside a typical telecommunication building when a lightning strikes at its lightning protection system (LPS). A model based on ‘circuit approach’ was constructed to simulate the building reinforced steel structure. Through numerical simulation, the magnetic field inside the building for two different types of LPS and for two typical lightning stroke positions was evaluated and compared. From the analysis result, some advices were proposed to protect electronic equipment against the impact of the magnetic field.