Applied Mechanics and Materials Vol. 700

Abstract: The different pretreatment methods for analysis of geosmin and 2-methylisobomeol by GC-MS in drinking water were systemically studied and applied, such as liquid-liquid extraction, solid phase extraction, and solid phase micro-extraction. The results show that solid phase extraction is the better one, which C18 and carbinol were adopted as filling and washing solvents. The relative standard deviation of SPE-GC-MS for analysis geosmin and 2-Methylisoborneol were 1.5% and 1.7%, the recovery rate were in the range of 98.8%~102.0% and 99.5%~104.0%, respectively. 2-methylisobomeol was the major taste and odor of a micro-polluted reservoir in later autumn to earlier winter, which was secreted by Planktothrix and Oscillatoria.

Abstract: Rainwater utilization is always paid attention by the government and research institutes in Beijing, as its lack of water resources. Lots of rainwater utilization projects were built in the urban and rural areas. More than 80 rainwater utilization projects were completed in Fangshan District, which located in the suburbs. They effectively saving water resources and improving the rural water environment. Combined with the characteristics of rainwater resources in Beijing, a new rainwater utilization mode about sewage purification and reclaimed water reuse appeared during the construction process, providing reference for promote rainwater utilization projects in Fangshan District.

Abstract: Modern urban water conservancy construction is supposed to keep "people and water in harmony" as the goal; the urban water conservancy project functions in flood control, drainage as its basics , meantime, it should also play social roles of ecological environment, landscape in the project. This article takes Heigangkou Reservoir ecological environment construction in Kaifeng as an example, briefly introducing the plane of its ecological management of the status quo, the revetment type design, and putting forwards some new ecological revetment structure materials and technologies.

Abstract: The nonlinear and uncertain of water environmental pollution,make the traditional water quality evaluation methods have limitations.In order to improve the accuracy of water quality evaluation,The paper put forward the water quality evaluation model based on improved wavelet neural network (Wavelet Neural Network, the WNN).Optimize the initial weights of wavelet neural network based on Adaptive Genetic Algorithm (Adaptive Genetic Algorithm, AGA),and then training the network by used wavelet neural network algorithm,finally,testing the trained network.The simulation results show that the combination of Adaptive genetic algorithm and wavelet neural network improved the efficiency of network training,and this method can be used in water quality evaluation, and the evaluation result has high precision and accuracy.

Abstract: The present study was implemented to investigate the trihalomethanes formation potential (THMFP) in drinking water treatment and to determine the impact of preozonation on the reduction of Trihalomethanes (THMs). The full-scale examination was carried out, using Luan River as the raw water. Two different preoxidation methods, prechlorination and preozonation were performed. THMFP and THM species were analyzed. The investigation indicated that 18.72% of THMFP was removed during preozonation. Further study on the distribution of THM species showed a significant reduction of Chloroform and bromodichloromethane, 20.62% and 17.39% during preozonation, respectively. The result suggested that the application of preozonation process is an effective method for reducing THMs generation in drinking water treatment. In the final effluent, the total removal rates of THMFP were 47.49% after preozonation and 55.67% after prechlorination.

Abstract: The T² statistic is one important indicator of statistical process control theory to identify anomalies of the multivariate industrial process. In the research field of the coal gas pre-drainage process control, previous achievements mainly based on the univariate control chart, which leaded to huge workload and facilitated some human errors. Against these problems, a more comprehensive and easy-to-use method based on the T² statistic was proposed. First at all, the basic thought and the principle of T² control chart was elaborated. Secondly, the data structure and data samples were provided after their principle component analysis. Finally, the multivariate control chart of coal gas pre-drainage process was established. Results show that the proposed anomaly identification method can integrate dozen of univariate control charts into one. Then technicians needn’t deal with many control charts in the same time and many human errors can be avoided.

Abstract: In order to improve gas drainage of soft and outstanding coal seam in Huainan mine area, for eliminating outburst hazard, hydraulic fracturing is applied at west one (13-1) rock cross-cut coal uncovering face. By analysising antireflection mechanism of hydraulic fracturing, hydraulic fracturing is designed and construct at rock cross-cut coal uncovering face, and then investigate the effect of hydraulic fracturing, at last it get a hydraulic fracturing complete set of technical system.

Abstract: Yalong river basin is located in the southeast of the qinghai-tibetan plateau. This area is the important mineral resources region, where ecological environment problems caused by mineral resources development are uncertain and complicated. It is necessary to understand the influence of mineral resources development urgently and control human activities scientifically. In this paper, the eco-environment influence of mineral resource exploitation is studied on basis of geochemical data and remote science, and dividing into mining point distance, soil type, land cover, vegetation coverage and the soil erosion. The method of principal component analysis is adopted to sort the corresponding degree of various factors. Then the impact of mineral resources development on ecological environmental factors can be mastered overall, which providing decision basis for mining development measures.

Abstract: The research has revealed the problem of sulfur dioxide emissions during the coal combustion. Combustion experiments were made for Shanxi coal at 1000oC. Red mud, carbide and shell powder were chosen as the primary sulfur-fixing agent. Through the experiment, the best ratio of Ca/S is 2.0 at 1000oC. When the ratio of red mud, carbide and shell powder were 50%, 15% and 35%, the maximum sulfur-fixing efficiency was 76.05%. Orthogonal experimental results showed that the best additive formula was 9% of Fe₂O₃, 5% of Na₂CO₃, 5% of ZnO. The maximum sulfur-fixing efficiency reached 89.23%. In addition, it was made thermogravimetric analysis of coal with different additives. By contrast, samples with sulfur-fixing agent generated two-stage combustion significantly, ignition point increased. The amount of coal residues with sulfur-fixing agent and sulfur-fixing additives showed an increase in the quantitative analysis.

Abstract: A deep potassium-rich old brine in Hubei Province contains a large number of rubidium resource. Separation of rubidium is very difficult due to the similar physical and chemical properties of rubidium with the other coexisting alkali metals (potassium, sodium, and lithium). The process of extracting and separating Rb from the old brine with 4-tert-butyl-2-(α-methylbenzyl) phenol(t-BAMBP) as the extraction agent and sulfonated kerosene as diluents was systematically studied in this paper. The concentration of extraction agent, alkalinity of the old brine, phase ratio, the extracting time and other related factors were investigated. The optimal extraction conditions were obtained as follows: the concentration of t-BAMBP was 1.0mol/L, the concentration OH^- was 0.6mol/L, the phase ratio was 3, the extraction time was 3 minutes. The percentage extraction of Rb could reach 91% for single-stage extraction, the separation coefficient of Rb and K reached up to 16.15. Sulfonated kerosene as diluent is non-toxic, high flash point, non-environmental pollution. A high extraction rate and separation factor for the development of rubidium resource of deep potassium-rich brine provided a reliable basis.