Applied Mechanics and Materials Vols. 71-78

Abstract: In order to investigate the adsorption of hexavalent chrome in wastewater by peanut shell, the orthogonal test was designed to find the best adsorption conditions such as pH value, temperature, adsorption time and adsorbent dosage etc. The results show that the peanut shell is a kind of economic and efficient absorbent; hexavalent chrome removal rate can reach more than 85%, when the hexavalent chrome wastewater concentration is 30mg/L, dosing 1g peanut shells into 50mg wastewater, adjusting pH value to 2.0, adsorbing 300min at room temperature.

Abstract: Heavy metals (Zn, Cu, Pb and Cd) concentrations using atomic absorption spectrometry were investigated in roadside surface (0-20 cm) and sub-surface (20-40 cm) arable soils along Shangzhi section of Harbin-Suifenhe railway, Heilongjiang province, northeastern China. The soil environmental quality on the base of the environmental background value criteria were evaluated respectively by single-factor pollution index (P_i) and Nemerow multi-factor pollution index (P_ij) method according to the first grade of Standards for Soil Environmental Quality of China (GB15618-1995). Except for Zn, concentrations of Cu, Pb and Cd in surface soil (0-20cm) were higher than that of sub-surface soil (20-40cm). Concentrations of Zn (106~293 mg kg^-1), Cu (17.9~22.4 mg kg^-1), Pb (18.2~24.6 mg kg^-1) and Cd (64~386 µg kg^-1) were lower than the values in China National Standards Grade II. The highest P_i of Zn, Cu, Pb and Cd are 2.93, 0.64, 0.70 and 1.42, respectively. The highest P_ij was presented in the 50-m distance soils.The results suggested heavy metals in soils 50-meter distance from railway were higher than that of 10- and 100-meter distance.

Abstract: The adsorbability of colloidal particles from different stages of a conventional water treatment plant was studied with the assistance of micro-membrane filtration experiment. The microfiltration (MF) performance and the scanning electron microscope (SEM) images of the foulants on membrane surface were investigated. The results showed that the particles in the ozonated water (OW) had the strongest adsorbability, and stronger than that in the clarified water (CW); and the particles in the sand filtrated water (SFW) had relatively weaker adsorbability than that in the raw water (RW). The particles in the sand filter backwash water (SFBW) were mainly consisted of detached aggregates and had weak attachment with the membrane surface.

Abstract: BOT is a new financing mode, which in the current is in the use of our infrastructure projects gradually. Infrastructure project in China has its own characteristics,and the government behavior in the running of these projects exists defects [1].By applicating the BOT mode in the infrastructure projects of China, combining the quantitative and the qualitative and analysis method, paper analyses the "defects" of the government behavior in the operation of infrastructure projects and optimize our government acts to reposition the role of government. According to the analysis and study of the thesis, paper puts forward the new government operating mode in the operation of the infrastructure projects that is not only applicable to the infrastructure construction, but also can be used extensively in other public project areas and in economic construction.

Abstract: According to the data related to infrastructure expenditure，project number and persons engaged in scientific and technological activities during 2003-2008 of Hebei，in addition to the gross domestic production(GDP),by using gray relevance analysis principle and method，this paper analyzes the relationship between scientific and technological input and economic growth and concludes that there is close relation between economic growth and scientific and technological input.Especially the project number has more effect on the GDP.The conclusion can provide some theoretical support forgovernment decision and some suggestions are also given.

Abstract: The durability research on the filter media is of great significance. It is necessary to establish a laboratory test method on it in practical use. A new testing method is provided for filter media durability under corrosive gas condition in the paper. PPS is selected as standard testing sample and it is tested in SO2 gas. Under 1000ppm SO2 and 200°C condition, both warp strength and weft strength of PPS increase at the beginning and then gradually decrease with duration. And the decrease of weft elongation is obviously higher than warp elongation for PPS.

Abstract: Although it is generally right that tunnel and underground structures are environment favorable, the practical situation strongly depends on the geochemical features of the rock mass to be excavated. When a tunnel is built in sulfide-bearing rocks, it is analogical to the environmental impact related to mining activities. This paper presents the features of the environmental problems related to tunnel construction in sulfide-bearing rocks and the measures to cope with the problems. It is shown that more effective options are available earlier in the tunnel life, especially at the stages of feasibility and design of a tunnel project.

Abstract: Recently, increasing nutrient (i.e., nitrogen and phosphorus) concentrations have been observed in the surface water of many countries and the non-point source (NPS) pollution has become an important factor in the deterioration of water quality in the Three Gorges Reservoir Area (TGRA). The spatial and temporal analysis of NPS pollution loads in the TGRA of Hubei from 2005 to 2009 were estimated using export coefficient model in this paper. The results indicated the nutrient from rainfall was the dominant NPS of both TN and TP pollution. The spatial analysis of N and P loads from NPS in the TGRA of Hubei showed that the nutrient loads in BD County and YL District were higher than the other two counties in the study area. These findings demonstrate that the model could provide a simple and reliable approach to evaluate N and P loads to TGRA of Hubei and may be useful for planning and management of the local agricultural watersheds

Abstract: The research of reservoir fluid-solid coupling theory is hot issues in home or foreign recently, In oil, civil, environment and geology, mining and other fields with a wide application. On the basis of summarizing the predecessors' achievements，according to the basic theory of rock mechanics, fluid mechanics in porous medium, geologic mechanics, calculated mechanics and fluid-solid coupling seepage, a mathematical and numerical model of seepage field and stress field coupling is developed in porous medium and the LiuNan blocks of JiDong oilfield wells.based area single phase Stress Field / Seepage Field in solving with the method of finite element software ANSYS, Contrast analysis of LiuNan blocks Coupling around of Field / Seepage Field is the change of average stress and total displacement. As can be seen from Table 3, after coupling the value of average stress and total displacement are greater than before coupling.The results show than it is important meaning for used to solve practical engineering problems.

Abstract: Based on a static experiment, this study researched the electrochemical oxidation process of simulated dye wastewater containing Acid Scarlet 3R in the two-dimensional electrolysing cell. This experiment investigated the effect of such various factors as current density, initial concentration, supporting electrolyte concentration, and the initial pH value on the color removal. The results of the experiment clearly indicated that the rate of color removal increased when the current density was increasing gradually; it decreased when the initial concentration was increasing; it originally increased and then decreased when concentration of electrolytes was increasing; alkaline condition was not conducive to the removal of color, and the effect of decolorization was better under an acid condition than under an alkaline condition. The optimum condition of disposing of dye wastewater is when the current density is 7Am/cm², electrolyte concentration is 0.04mol/L, pH=2.5, under the condition of which the color removal rate could be 96.06%.