Applied Mechanics and Materials Vol. 737

Abstract: In order to investigate the disposal of plutonium by Gd₂Zr₂O₇, Ce-doped Gd₂Zr₂O₇ were fabricated by high temperature solid state reaction at 1500 °C under atmospheric pressure for 72 h. XRD and SEM studies were exploited to characterize the crystal structure and microstructure of the synthetic samples. The results revealed that Gd₂Zr₂O₇ shows a single pyrochlore structure while Gd₂Ce₂O₇ exhibit a defective fluorite structure. The microstructure of the samples was relatively dense, and the grain size was in the range of 3 - 6 μm.

Abstract: Valuable metals in smelting sludge from smelting industry have a recovery value. In this work, for realizing waste recycling effectively, selective and multi-step leaching of valuable metals was investigated with scrap copper-smelting sludge as research object. The effect of the concentration of sulphuric acid on leaching rates of valuable metals was investigated first. The results showed that the leaching rates of Cu, Zn and Ni were 6.1%, 59.4% and 63.3% at the acid concentration of 65g/L. Then, the results of the selective and multi-step leaching indicated that the leaching rates of Cu, Zn and Ni were over 90% after two-step leaching. In third step, the content of Cu in leached residue was 6.68%, which was higher than origin sludge. Repeat three-step leaching process above, Zn and Ni were leached selectively and Cu was accumulated in leached residue continually.

Abstract: There was studied the composition and the fatty acid content of the lipid fraction obtained by extraction the rice straw cultivar Lugovoi (Oryza sativa L.) by ethanol and chloroform solution in a 2:1 ration. It was found that the yield of lipids from the straw was ~ 9% from the weight of the dry sample. The main components of the lipid fraction are palmitic and oleic acids. The comparative analysis showed that the yield of fatty acids and their composition depends on the plant species and the type of feedstock.

Abstract: In this study, IC anaerobic reactor was made to deal with the wastewater with high-concentration sulfate, the sludge from sewage treatment plant was put into two cells of IC reactor to domesticate sulfur-reducing bacteria (SRB), artificial water was made to simulate the wastewater with high-concentration SO₄²⁻. In order to remove the SO₄²⁻ efficiently, two stages were designed in this study: sludge domestication stage and concentration strengthening stage. In sludge domestication stage, SRB could grow normally, the removal rate of SO₄²⁻ was between 34.14% and 36.2%;in concentration strengthening stage, removal rate of SO₄²⁻ was between 26% and 26.86%,demonstrating that SRB could grow and remove SO₄²⁻ in such high-concentration SO₄²⁻( 38000 mg/L ) wastewater.

Abstract: The pollution sources and characteristics, their environmental influences and the remediation techniques for the contaminated soils in mine were discussed systematically in this paper. For each remediation method, the applicable scope, and its merits or limits in the remediation of contaminated soils in mine were expounded respectively. Since the mine contaminated sites commonly had large pollution scope with combined pollutants, there was limited corresponding technique for the remediation of this complex contaminated site, not to mention the rare industrialized application, so combined with various remediation techniques to establish a complete set of remediation repertoire was needed.

Abstract: Reverse osmosis membrane is usually used to desalination. With the development of membrane materials and technology, the performance of reverse osmosis membrane is improved continuously, and the interception rate of organic matter is higher, the separation rate of the organic matter is obviously improved. The research progress and application status of separating organics in aqueous solution by reverse osmosis membrane is presented in this paper. The future research direction and application of reverse osmosis membrane for separating organics from aqueous solution were also analyzed and prospected.

Abstract: Supercritical Water Oxidation (SCWO) is a unique environmentally safe technology being widely used in industrial wastewater treatment for its remarkable superiority of removes organic matters efficiently. Characteristics of supercritical water, fundamental principle and flow sheet of SCWO were introduced. Meanwhile, application situations of SCWO in different fields of industrial wastewater treatment were presented in detail, the existing problems in its application were pointed out. At last the prospect for the development of SCWO was also proposed.

Abstract: This article deals with a risk analysis in water management. The first part of this paper highlights critical points of individual parts of water supply systems and divides individual hazards into groups depending on their origin. The second part of the paper deals with a risk analysis itself and with the basic division of methods for determining it.

Abstract: With the living standards improvement of rural residents, people pay more attention to the safety of drinking water in China. As the final step in drinking water treatment, disinfection technology has received much attention. At present, drinking water disinfection process is mainly involved in chlorine disinfection, chlorine dioxide disinfection, chloramine disinfection, disinfection of potassium permanganate, ozone disinfection and ultraviolet disinfection. However, due to limitations in rural economic conditions and management level, only ozone disinfection and ultraviolet disinfection are suitable for rural areas in China. This paper described some of the application problems and limitations in drinking water disinfection process, as well as the select principle in rural areas. The principle, research status, trends and issues in application of ozone and ultraviolet disinfection technology were emphatically introduced. Finally, the development of drinking water disinfection technologies was discussed.

Abstract: Based on the grey theory, a grey correlation evaluation model (GCEM) was built for risk assessment of river water quality. Five pollutants are used for risk assessment indicators, while the risk class was determined by the maximum principle. The results indicate that the water quality risk is higher in Baoji Weihe River of China. Potassium permanganate index risk is the maximum and the second is BOD₅. The comparison with other methods confirmed that evaluation of GCEM is agreement with the actual condition. Moreover, this method is simple and solid for water risk evaluation and would be used for rive water environmental administration.