Applied Mechanics and Materials Vols. 316-317

Abstract: To clear the effect of freezing and thawing on the soil phosphorus adsorption and desorption of northeast China high latitude forest wetland, the change of soil phosphorus elements after five complete freeze-thaw cycles was analyzed with Wuyiling National Wetland as experimental subjects. Result shows that the soil phosphates desorption increased after influenced by five complete freezing and thawing. Soil sample which initial phosphates concentration is 40、80、240 mg/L reached minimum value after three freeze-thaw cycle and then increased. Compared to the without freeze-thaw soil, phosphorus adsorption capacity of different initial concentrations of phosphate solution samples was increased after five freeze-thaw cycles indicating that freeze-thaw cycle has obvious effect on soil phosphorus adsorption and desorption.

Abstract: Aiming at the harsh environmental situation at present, this paper applied the interval fuzzy linear programming method, and combines environmental management policy about the total control of regional atmospheric pollution, to set up an optimization model for total amount control of regional atmospheric pollutants under uncertainty. Through the model results, the total cost of reduction in instance case was [119.98, 125.82] (10⁸ yuan), and the membership of SO₂ and NO_X predicted through the model were [31.00, 32.64] and [23.62, 25.94] (10⁴ tons), respectively. This model could get the minimum total cost of emission reduction, and be used as the technique and theory guider for the total amount control of atmospheric pollutants.

Abstract: Combining environment policies of structure emissions reduction, engineering emissions reduction and management emissions reduction, this paper uses an interval-fuzzy linear programming and builds an optimization model for total amount control of regional water pollution, on account of severe water pollution condition. The developed model is applied to a case of Hunan Province to validate its validity and reliability. The optimal result demonstrated that the emission reduction of COD and NH₃-N are [43.39, 47.57] and [7.05, 7.64] (104 tons), and the optimal total costs of reduction is [35.11, 37.35] (billion yuan), which decreases 6.32~11.20% than the existed recommended scheme (39.87 billion yuan). This method can be used for providing technical support and thus achieves the 12th Five-year goals of the environment protection plan more effectively.

Abstract: To assess how the human exposure to environmental carcinogenic polycyclic aromatic hydrocarbons (PAHs) contaminant generated from a typical oilfield, we used a recommended exposure risk model, appraised with actual measured PAH concentration in an oilfield soils. Hierarchical clustering method was also applied to classfied the total exposure risk (carcinogenic and non-carcinogenic) of 16 PAHs, and four risk grades were obtained as zero risk, low risk, medium risk, and high risk. It was found that ingestion was the major exposure route among the three exposure routes. Risks of dibenz(a,h)anthracene and benzo(a)pyrene were higher than the other contaminants, and represent high risk grade.

Abstract: A research on tailings water of phosphate concentration is carried out to determine whether the water can be send back to the flotation process. The settlement tests of tailings was conducted, and the water quality analysis of upper tater was performed. Finally, we used the mixed water with different proportion composed of tailings water and tap water for flotation tests. Flotation results indicated that backwater has little influence on the flotation but could be very good used.

Abstract: In this study, a Fe(III)-impregnated sorbent was prepared from sugarcane bagasse and FeCl₃ solution via carbonization/activation in a muffle furnace at 500 °C for 4h. Batch experiments were carried out to determine the capacity of the Fe(III)-impregnated sorbent to adsorb As(V) from aqueous solution. The dynamical data fitted very well with the pseudo-second-order kinetic model and the calculated adsorption capacities of 4.8263, 5.2219 and 7.1225 mg/g were equal to the actual values of the experiments at temperatures of 20, 25, and 35 °C, respectively. The experimental data were modeled by Langmuir and Freundlich isotherm models. The Langmuir isotherm with R² values of 0.9926-0.9968 could yield better fits than the Freundlich isotherm, and the adsorption was endothermic, indicating monolayer adsorption of As(V).Freundlich isotherm, and the adsorption was endothermic, indicating monolayer adsorption of As(V).

Abstract: Zero-valent iron nanoparticles( nano-Fe0) were applied as a treatment tactics for a uranium-containing mine wastewater taken from Shaoguan, Guangdong, China. Different factors including pH value, nano-Fe0 dosage,reaction time were introduced to study the effect posed by those factors.Results indicated that those factors have significant effect on uranium removal rate.The best removal effect happened when pH=5~6, nano-Fe0 iron dosage is 2g/l,reaction time is 1h.It is also demonstrated that nano-Fe0may be an effective material for treatment of complex uranium-contaminated effluent.

Abstract: Abstract.The amount of water storage change in Tangnaihai basin is obtained by using monthly gravity field data, which is derived from GRACE satellite between 2003 and 2008, with Gaussian filter. Combined with the same time period monthly precipitation data of the regional meteorological stations, we analysis spatial-temporal variation trend of water storge change in Tangnaihai basin for nearly 6 years. Results show that the spatial distribution of water storge change in Tangnaihai basin has obvious difference,water storge change is more in west than in east area.Water storge change has obviously seasonal variation change, and it has the same process with precipitation.The trend of water storge change increase in annual in study area. Water storge change increased from 2003 to 2008 in totally in Tangnaihai basin.The average rate is 0.5 mm/month,and water storge change reduced about 6.1*106 m3.

Abstract: This paper mainly made a detailed review on cadmium-calcium hydroxyapatite solid solutions. There are including introduction, synthesis method and controlling conditions, and the summary of study results at home and abroad. Finally, gave the conclusion and prospect of the author.

Abstract: Effects of thermal discharge from a coastal power plant on phytoplankton community were determined in subtropical Zhanjiang Bay. Two sampling transects were chosen up and down the Zhanjiang Plant in the Zhanjiang Bay, Nine stations were located along the two transects, which were divided into four zones. Monthly boat cruises were undertaken in the bay at spring up here, tide ebb slack, neap rise open and neap tide ebb slack respectively, during the period April-October 2012. Species diversity (H') showed a distinct increasing gradient from the most thermally polluted zone to the healthy zone. The more distinct gradient occurred at spring tide. Species diversity fluctuated during April-October 2011 and four sampling tide times with no visible patterns. Evenness showed indistinct gradient from the heated water source to the control zone, and fluctuated during April-October 2011 and four sampling tide times with no visible patterns. Species richness, cell count and Chl a concentration at mixed and healthy zones were significantly higher than that at heated zones, with the maximum value recorded at mixed zone, and showed seasonal and tidal changes with no obvious pattern.