Advanced Materials Research Vols. 518-523

Abstract: Based on deep search on the mechanism about evolution of water bloom, Petri net is utilized to construct the simulation model for evolutionary process of water bloom`s pattern. The formation of water bloom is considered in the key factors and different stage. Through test and simulation, the results verify that the petri net model can be realized, which describe the evolutionary process of water bloom`s pattern, so provides another effective approach about the evolution of water bloom.

Abstract: In this paper, the soil water characteristic curve (SWCC)of Xinjiang Altay bentonite under different stress states, different initial dry density and different initial water content has been tested by dialysis method and vapor phase method, and the impact of the various factors on the water retention characteristics of Xinjiang Altay bentonite has been analyzed comprehensively. The mercury intrusion porosimetry (MIP) test has been carried out on the soil sample, and then the SWCC is predicted by the Pore size distribution(PSD)curve which is got from the MIP test. Finally, the predicted SWCC is compared with the measured SWCC, and it shows that the predicted SWCC is close to the measured values, but there are deviations in the high suction.

Abstract: In demonstration and promotion of treatment works for rural domestic sewage, the technical solutions should consider not only the treatment technology’s effectiveness, but also its economy and suitability for specific rural areas, that is, the advanced and applicable technology should be selected. In this paper, a rural domestic sewage technology evaluation system was established with the analytic hierarchy process as the assessment method to evaluate the alternative technology options and made decision. The indicators quantification and standardization and the weight determination were also promoted. Finally, a case study was conducted. The method can be used as decision support analysis tool in demonstration and promotion of treatment works for rural domestic sewage.

Abstract: The immobilization of simulated radioactive sandy soil waste by using self-propagating high-temperature synthesis (SHS) was investigated. The products were characterized by density, X-ray diffraction, and scanning electron microscope. The leaching rate of tracer element was measured by the method of PCT (product consistency test). The SHS immobilization typically results in products containing amorphous phase and crystalline phase. The volume density of the final product is over 3.0g/cm3. The tracer element Ce in the final product mainly forms crystalline phase of CeAl11O18 and Ce2SiO5 when the amount of CeO2 in the raw material is large than 1%. The leaching rate of Ce for 28 days is about 10-5 g•m-2•d-1，which is much lower than that of the borosilicate glass solid form. the leaching rates of Ca, Si, Al and Fe during 28 days are about 10-3～10-4 g•m-2•d-1

Abstract: Spills and leaks of petroleum hydrocarbons such as gasoline, diesel, motor oils, and similar materials have caused widespread contamination in the environment. The migration and distribution of petroleum hydrocarbons in the vertical and horizontal profiles of soil were studied by the stimulating experiment. Results showed that the soil pollutions could diffuse in vertical and horizontal directions after petroleum hydrocarbons leaks. The petroleum hydrocarbons mainly spread vertically in the soil and the horizontally migration was relatively slowly. The migration distances were increased with a logarithmic growth dependence on the time both in horizontal and in vertical direction.

Abstract: To identify the concentration and spatial distribution of cadmium (Cd) in agricultural soils, 207 soil samples were collected from Chaoyang and analyzed based on pollution index methods and GIS. The concentration of Cd in the soils of Chaoyang ranged from 0.030 to 0.687 mg/kg, with an average concentration of 0.246 mg/kg. The evaluated results of Cd in agricultural soils of Chaoyang shows that the pollution excess rate is 2.90%, the total agricultural soil environment of Cd was still clean, but some areas were accumulated by Cd. The differences between two evaluated methods indicate that evaluated criteria had a direct impact on the evaluation results, compared to integrated pollution index, the Geoaccumulation index method was more accurate and objective.

Abstract: Non-point source (NPS) pollution load of N and P in Nansihu watershed were simulated based on SWAT model. The Sihe watershed was selected as typical watershed for east of the lake, and the Dongyu watershed was selected as typical watershed for west of lake. The two typical watersheds were simulated respectively, and then the models were used to simulate the other rivers basins in the Nansihu watershed. Data collected in the period from 2001 to 2007 was used for calibration, while data collected from 2008 to 2010 was used for validation. Then the spatial distribution of NPS pollution in Nansihu watershed (2010) was simulated with the validated model. The result indicated that the SWAT model could simulate the no-point source pollution in Nansihu watershed with high-precision. The watershed was polluted seriously with N and P. The TN was mainly composed of dissolved form, and the TP was mainly composed of adsorbed form.

Abstract: The continuous auto-monitoring methods were used to analyze PM10、SO2、NO2 concentrations in atmospheric environment of three types of function areas in Shenyang, and the atmospheric environmental quality were evaluated by using National Ambient Air Quality Standard GB3095-1996 and API methods.The results showed that annual average concentration of PM10 surpassed 0.1 fold of the National Air Quality Standard II, that of SO2 was below the Standard II, that of NO2 was below the Standard I in the second type of function area, the air quality in the first and third types of function areas met the requirements for the Standards in 2010.There were 328days with the air quality of good and better. There were 329days with PM10 as primary pollutant and 36days with SO2 as primary pollutant. According to the main factors inffluencing the air quality of Shenyang, the strategies for realizing atmospheric environmental quality goal in creating national eco-city were put forward.

Abstract: The finite difference method that is the finite element method is used to solve the plane continuous problems. In this article, the theory and method of the finite difference method, as well as the application on the boundary problem are introduced. By analyzing the potential flew field equation and liquid diffusion equation, they are discreted using the difference method and the numerical analysis under certain boundary condition is conducted. In air pollution, the smoke in the diffusion is typical planar continuous problems. In this paper, the finite difference method is used to analyse and simulate the spread of the smoke.

Abstract: The composition of mixed chemical wastewater is more complex and biodegradability of its is bad, biochemical treatment effect should be further improved. Many-point-water-inflow bioreactor used in this experiment, through controlling hydraulic retention time(HRT), concentration of active sludge of the aeration tank, trace element content and so on, gets a better treatment effect. When water temperature is 25°C, HRT is 5h, 10h, 15h, 20h, 25h,COD removal rate is 60.37%, 82.62%, 89.44% , 91.02%,91.07%. According to the iron content of influent, plus 0.5mg/L ferrous sulfate into influent, the removal rate of COD is increased , activated sludge floc of the sedimentation tank is denser and settling. By changing the activated sludge return ratio to change the activated sludge concentration of the bioreactor, experiments shows that the removal rate of organic matter is better with the activated sludge concentration about 4000-5000mg/L. Influent qualities indicate that this biological treatment has good effect on mixed chemical wastewater.