Advanced Materials Research Vols. 383-390

Abstract: According to characteristics which generate from reclaimed water for ecology environment, we utilize event tree analysis (ETA) method to analyze the risk transmission way of reclaimed water, on the base of it, the evaluation index system which reclaimed water for ecology environment effect is preliminary established, and indicator weight is determined by entropy value method. Finally, we set up comprehensive evaluation model using entropy value and gray connection method, combine with the risk matrix to qualitative describe the risk level of comprehensive evaluation result.

Abstract: According to the fact of coal-based energy consumption in China, the paper especially introduced energy consumption structure, besides the factors of economy, population, energy intensity using the STIRPAT model to analyze the impacts of CO₂ emissions factors. The results show that economy, population and urbanization level have positive effects on CO₂ emissions, on the other hand energy intensity and energy consumption structure have negative effects. At the same time, the factors’ contribution were calculated, which had different values, the highest is the economy. Considering the fact that economy and the urbanization develop fast, more energy saving technology and clean energy technology must be applied to save fossil fuels and reduce the CO₂ emission.

Abstract: Ultrasonic disinfection is safe and effective, but requires high power consumption. For economic considerations, ultrasound and chlorine can be combined to promote a wider range of applications. In this paper, we investigated the disinfection effect of secondary effluent with low-frequency ultrasound and sodium hypochlorite. The optimal conditions were determined by changing the ultrasound intensity, exposure time, chlorine dosage, and chlorine contact time. The results showed that ultrasound can significantly enhance the effects of chlorine disinfection. When the coliform bacteria is 106~107CFU/L, the dosage of chlorine at 4~6mg/l can meet the national discharge standard (less than 104 CFU /L). However, the chlorine dosage can be further reduced to 1~2mg/l if we add 30 s of ultrasonic radiation, thereby reducing the disinfection by-products. Orthogonal experimental results show that the relative importance of the disinfection factors: chlorine dosage> ultrasonic irradiation time >chlorine contact time> ultrasound intensity.

Abstract: Reducing the adverse impacts to environment is a more and more important subject in electrolytic manganese industry. Life cycle assessment (LCA) has been a hot tool to measure the type and size of environmental impact. This paper firstly applied LCA on two different processes of producing electrolytic manganese. One process is the resourceful utilization system of high sulfur coal and low grade pyrolusite (the novel process for short)in which high sulfur coal is burned to generate power and emission SO₂, then the SO₂ is absorbed as reducing agent to leach the pyrolusite with 30% MnO₂ grade. The other process is prevalent interiorly, called traditional process where the power is supplied by standard coal combustion, and sulfur acid leaches the manganese ore with 18% Mn grade. Life cycle software converts the original data to nine different kinds of indexes that are able to indicate types and sizes of environmental impacts. Results show that: among nine environmental impacts, the proportion of abiotic depletion potential (ADP) is biggest in both processes, but the value of the novel process is 23.25% smaller pointing the process saves more resource. All the values of other important impacts including GWP, Waste Solids, AP and RI of the novel process are less than those in traditional process. Especially, the value of acidification (AP) in novel process was -2.10×10^-8 < 0, which means the novel process could control the acidification. In addition, through the composite index, using high sulfur coal in the novel process hasn’t bring any more serious impact than using standard coal. Therefore, LCA has provided rational evidence to prove that resourceful utilization system of high sulfur coal and low grade pyrolusite is more efficient and environmentally friendly and pointed which environmental impacts and life cycle links need improving . This paper could provide a reference for further environmental impact assessment of electrolytic manganese industry and an objective basis for decision-making.

Abstract: The fuel characteristics of municipal sewage sludge are suitable for dual fluidized bed(DFB) gasification, which can get middle calorific value gas through volatile pyrolysis, and reduce volume through char combustion. The hot test results of municipal sewage sludge on DFB rig were showen that the temperature distribution along combustor heigh is uniform, and the carbon content of fly ash is about 2~3%. In the experiment, with the increase of gasifier temperatrue, the more volatile of the sewage sludge was pyrolyzed. When the temperature of the gasifier reached 800°C, the calorific value of gas was 6.9MJ/Nm3; the emissions of SO₂, NO_x and HCl were appropriate to the standard. The leaching toxicity of heavy metal of the fly ash was lower than the discharge standard.

Abstract: There are abundant mineral resources in China. On the one hand, we should ensure the effective supply of resources in the process of the economic and social development. On the other hand, we should change the way to develop the mineral resources extensively, reduce the pollution and ecological environment disruption minimally in the process of developing the resources, control the mine environment which is disrupted before and improve the production and living environment in the mine zone to achieve the sustainable development in terms of economy, environment and resources. At present, the development of mineral resources in China has brought enormous benefits to us. The main present and future mission is that we should raise our awareness of mine environmental protection, control the mine environment and reduce the disruption.

Abstract: The pilot block is a heterogeneous reservoir with low permeability which is only 100-200(mD). Polymer flooding will be used to enhance oil recovery (EOR). Therefore, some experiment will be carried out in this pilot block .According to the simulation results, we can infer the effect factors of the polymer flooding such as concentration, injection rate, slug amounts, and well pattern. It gives us effective information for the field development plan.

Abstract: The influence of grain size on the magnetism in some ferreous magnetic nanoparticles was studied in experiment. It is found that the γ-Fe₂O₃ nanoparticles present the superparamagnetism. The coercivity and the remnant magnetization approach to zero. Moreover, the pure nanoparticles γ-Fe₂O₃ and Fe, under the normal temperature, the specific saturation magnetization decreases along with the grain size reduces. According to the basis magnetic domain structural theory, the grain size of the samples is all below the critical dimension ds.

Abstract: In this paper, a precipitation method is investigated to prepare nanoscale zinc oxide (ZnO) as the precursor of silver coated antibacterial nanocomposite. Subsequently, silver loadeded zinc oxide nanocomposites (ZnO/Ag) are prepared by hydrolysis method. The average diameters and morphology of ZnO nanocomposites before and after silver loaded were compared. The results showed that the zinc oxide powder presented good dispersibility and uniform size a average diameter of 170 nm. Silver was coated on the precursor successfully, and the diameter of ZnO nanocomposites increased slightly.

Abstract: Nickel furfuraldehyde thiosemcarbabazone adduct of the type, NiCl₂(L)₂ (L = furfuraldehyde thiosemicarbazone) was synthesized by the reaction between nickel dichloride hexahydrate and furfuraldehyde thiosemicarbazone in 1:2 stoichiometry. The resulting compound was characterised by elemental analysis, IR, ¹H and ¹³ C{¹H} NMR spectral data. It was further used as a single-source precursor for the deposition of nickel sulfide thin films by aerosol assisted chemical vapour deposition (AACVD) technique and the nickel sulfide nanocrystallites by pyrolysis and solvothermal decomposition methods. The thin films obtained were characterised by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis by X-rays (EDAX) and atomic force microscopy (AFM). The nanocrystallites obtained were also characterized by XRD, EDAX as well as transmission electron microscopy (TEM). The SEM images of the thin films show formation of different morphologies of nickel sulfide, i.e. nanoball-like, nanowires to flower-like depending on the growth temperature. The mechanism for the variation of the morphology with the growth temperature has been proposed. The XRD of the nanocrystallites obtained matches with the hexagonal phase of nickel sulfide and the TEM images show formation of 10-50 nm spherical nano-crystals.