Advanced Materials Research Vols. 1065-1069

Abstract: To promote engineering application of municipal sludge pyrolysis technology and reduce economic cost of sludge pyrolysis operation, the paper discussed the feasibility of sludge-based char application in three aspects: sewage adsorbent, fuel and soil improving agent. Conclusion: the sludge-based char on SCOD adsorption time in the 30min reaches saturation, the SCOD removal rate above 30%; the removal rate of sludge-carbon on A/O reactor effluent COD have less effect, but there are certain effect on nitrogen removal; the sludge-based char can be burned at 400°C, release a lot of heat, it can be used as a low-grade fuel; the sludge-based char can promote plants growth, and has a good safety performance, may be used as a good soil improving agent.

Abstract: This paper makes a summary of factors influencing sludge composting on based on the reference to recent literature. As one of the effective ways to deal with the sludge resources, sludge composting has been studied by many scholars, with fruitful research results in aspects of condition optimization and process. The literature reveals that the main factors affecting the success of sludge composting include filler, moisture content, carbon and nitrogen ratio, thermophilic microbial agent, heavy metals and odor control.

Abstract: Based on the analysis of the dynamics of carbon price volatility, this article proposes to develop a combined extreme value theory and conditional variance based Value-at-Risk model (GARCH-EVT-VaR) for short-term risk measurement and estimation of the carbon spot market under the European Union Emission Trading Scheme (EU ETS). The model is implied to the EUA spot market and compared with the traditional GARCH-VaR model, the empirical results show that the GARCH based model underestimates market risks by overlooking the great price shocks, but the GARCH-EVT based model has the ability to take those extreme jumps into its risk estimations.

Abstract: While the Three George Dam might help in utilizing hydraulic power, historic weather data showed that the Three George Dam has a serious impact on the relative humidity for cities in the reservoir area. We conclude that the cooling energy consumption in Chongqing may have increased about 31 per cent, provided that the Three George Dam had not been constructed.

Abstract: Climate change is a hot issue on the current time and snow melting process in alpine areas has be affected on the background of climate change, so it is necessary to study snow melting process especially the snowmelt model. In view of the shortcomings of the degree-day model (DDM), the double layer snow-melt model (DSMM) is improved and developed based on the original theory. Then the simulation of the snowmelt process of the upper reaches of Lancang-Mekong River is performed by the improved double layer snow-melt model (IDSMM) and DDM respectively, the simulation results are analyzed in view of model theory, snowmelt critical control conditions, the effects of the simulation and working conditions in the changing environment. The results show that IDSMM based on the energy and mass balance is superior to DDM in the snowmelt physics mechanism, and it not only can simulate the snow melting process, but also can simulate many physical processes, such as the canopy interception of snowfall, vaporization and sublimation loss in evaporation, the second precipitation from canopy surface, the process of snowmelt water freezing again and so on. The simulation results of snowmelt process is more tally with the actual situation and it can provide a reference to the research of snow and ice hydrology and the whole water cycle in a changing environment.

Abstract: By indoor artificial rainfall simulator and slope plot test, the regularity of runoff and sediment yield of five types top soil— timber forest, shrubby grassland, terrace, slope cropland and waste-grassland under six kinds of rainfall intensity were studied in Danjiangkou Reservoir on southwest mountains of Henan Province to provide a scientific basis for comprehensive control of regional soil and water loss, to ensure the safety of water quality in the reservoir. The conclusions were that: (1) Land use types had less influence on the runoff comparing to sediment yield. (2) Sediment yield had obvious power function relationship with the runoff amount. (3) Bed load took up majority in the sediment yield of farmland soil while the bed load almost equaled to the value of silt load in woodland soil.

Abstract: Located in the junction of Dadu River, Qingyi River and Minjiang River, Angu Hydropower Station has the typical characteristics of plateau estuary wetlands. Since river systems are inter-relate and interact each other here, the transitional zone is with the ecological characteristics of rich biodiversity, frequent human disturbance and fragile ecological environment. According to characteristics of regional wetland ecosystem, and based on the specific investigation on the regional ecological characteristics of the flora and fauna, sediment and water quality, this research built an index system and evaluated the function of ecosystem. And then taking it as basis, this paper distinguished the effect mechanism of different driving factors on wetland ecosystem with the method of gradient analysis, so as to provide theoretical basis for the ecological restoration of this region.

Abstract: Single man-sieving sand materials were tested in Constructed Rapid Infiltration System (CRI). We selected two different sand sizes as filling filter materials, with three different heights in 15cm, 30cm and 45cm respectively. The system was operated for totally 11 periods in 33 days under a hydraulic load of 1.5m/d and wetting-drying ratios of 1:5. Relevant data about COD, N and P in the effluent are then analyzed. Results show that Constructed Rapid Infiltration System can effectively remove the pollutants in municipal wastewater, thus reduce the adverse effects to local area, which can be feasible to apply as the secondary treatment in small towns. Test shows that under the selected hydraulic load and wetting-drying ratios, the optimal operation condition is the 45cm-high packed column, with the removal rate of 35~75% COD, 50~100% dissolved orthophosphate and 55~98% TP, which was far beyond the normal CRI removal rate of TP as low as 30%, to imply a innovation method for integrated waste water treatment system, especially for TP

Abstract: Impact Factors of reducing U(VI) by the Shewanella oneidensis Were studied in this study. The results showed S. oneidensis has highly resistant to acid and Uranium. U(VI) initial concentration has the very big influence on reduction of U(VI) and the optimum U(VI) concentration is 30mg/Lwith removal rate of 95.02% at 4 days, Metal ions Cu2+,Mn2+ and Ca2+ impact on the reduction of U(VI). equal concentrations of Cu2+ and Mn2+ could cause varying degrees of inhibition of U(VI) reduction, Ca2+ acted as a weak role in promoting the reduction, the coexisting ions of SO42-and low concentration of no3-(<0.5mmol/L) did not markedly influence the reduction efficiency of U(VI). zero alent iron (ZVI) can accelerate the reduction of U(VI) by the S. oneidensis .

Abstract: Halimeda is an important reef-building green alga. Scanning electron microscopy (SEM) and energy spectrum tests on green and white Halimeda collected from Shidao Island in the Xisha Islands show that carbonate is predominantly deposited in the cortexes and medullas, especially in the aragonite raphides of them, as the case of calcium carbonate. These modern carbonate sediments are then compared with their ancient counterparts that are collected from Xichen-1 well in the Yongle Atoll, where a large number of Halimeda segments have been recognized in about 100-m-long late Miocene-middle Miocene whole-coring succession. In addition, there are developed great numbers of algal-frame holes, including secondary dissolved pores and intercrystalline pores in the medullas and in aragonites between cysts, which have formed particular network systems and pore throats.