Advanced Materials Research Vols. 550-553

Abstract: In order to optimize the process conditions for regeneration of activated carbon form spent catalyst resulted from 3,4,5,6-tetrachloropyridine-2-carbonitrile synthesis. A two-step process involving the thermal desorption of spent activated carbon and the activation of activated carbon treated by thermal desorption with steam was designed. The influence of desorption temperature, time and the flow rate of nitrogen on the yield of chlorides, the iodine adsorption capacity and the yield of activated carbon were investigated, respectively . The optimal desorption conditions were: temperature of 650°C, time of 90min and the flow rate of nitrogen of 30ml/min. The yield of the chlorides obtained under the optimal conditions was 14.85%. The regeneration of activated carbon treated by thermal desorption with steam; the optimized conditions analyzed by RSM were regeneration temperature of 696°C, time of 84 min and flow rate of steam of 0.58g/min. The experimental results on the optimized conditions were iodine adsorption value of 1003.59mg / g, These methods can not only recover chloride in the spent activated carbon, but also the regeneration activated carbon could partially replace the fresh activated carbon, which would bring an obvious economical benefit and social benefit.

Abstract: In order to reuse the waste originated from poly(phenylene sulfide) (PPS) production in stead of combustion, the oligomeric materials in the waste were recovered as raw materials. The recovered materials, then, were used to react with sulfur in molten state to produce polymeric resin. The structure and thermal property of oligomeric materials and their derived polymer were characterized by elemental analysis, infrared spectroscopy, X-ray diffraction and differential scanning calorimetry. The results showed that oligomeric materials are a series of PPS oligomers, and their derived polymer is poly(arylene sulfide)s (PAS). The thermal transition temperatures of obtained PAS are higher than those of PPS oligomers, which are attributed to the increase of molecular weight. It is desired that the yielding PAS has potential applications as plastic, coating, or filler materials.

Abstract: The crosslinked starch microspheres(CSM) were synthesized from soluble starch by inverse suspension polymerization with N,N′-methylenebisacrylamide as cross-linking agent. Experiments showed that adsorption isotherms of CSM for Cd(II) and Pb(II) could be described by Freundlich model, while that for Cu(II), Cr(III) fits well with Langmuir equation. The equilibrium capacity of Cu(II), Cr(III), Cd(II) and Pb(II) on the CSM were 1.10, 0.87, 0.35 and 0.31 mmol•g-1 respectively at 25°C, when adsorption process was undertaken with initial concentration from 0.7 to 11.5 mmol•L-1, and adsorption kinetics were examined according to the adsorption isotherm. Furthermore, the impact bring by other ions to CSM adsorption of Cu(II) were investigated in details.

Abstract: The hydrological effect of frozen soil is a particular hydrological phenomenon in frozen regions, which mainly performs in three aspects as following: (a) The poor permeability or impermeability of the frozen soil changes the infiltration and evapotranspiration process in soil and affects the storage and thawing process. (b) Frozen soil changes annual and inter-annual runoff variation process in a watershed. (c) Frozen soil influences and regulates the global climate. Based on the analysis of the frozen soil effects on the evaporation, infiltration and runoff in current research, this paper systematically analyzed relative researches on hydrological effects of frozen soil in recent years from environmental characteristics, data sources, research methods and major conclusions. The main conclusions are as follow: In China, research on hydrological effects of frozen soil started relatively late and developed slowly; There are few initial research on frozen soil hydrology and most research concerning which has been focused on the mechanics of frozen soil engineering rather than the discussions on hydrology; Future development of frozen soil hydrology in should be strengthened in some other aspects. Research on hydrological effects of frozen soil can lead to better understanding of this exceptional hydrological process, which has great significance on utilization of water resources and ecological environment protection in cold regions.

Abstract: Through analyzing the current water resources environment and current situation of groundwater utilization, the allowable water yield in the study area is calculated to be 11.0×104m3/d by using the water balance method. Then, using the amount as constraint condition, the critical groundwater levels are decided. Furthermore, a management scheme of total amount control of groundwater exploitation is given, which includes 3 aspects: (a) Building the monitoring well system; (b) Establishing the association for water users and water utilization groups; (c) Setting up a whole rewards and punishments regulation. This study is expected to provide scientific references and methods for relevant research.

Abstract: Heiyu Lake zone of Daqing is located in the southwest hollow borderland of Heiyu Lake and on the arching transitional zone of Daqing placanticline. Based on the geological background of Heiyu Lake, this paper analyzes the landform, the regional geological structure, the formation lithology and the irruptive rock and other metallogenic conditions in detail. The indispensable geological conditions for forming geothermal field in layers were summed up. Combining with the development characteristics and geophysical data of formation, the bore hole site of geothermal well and target stratum were ascertained. The four major elements of forming geothermal resources in this region were confirmed by carrying out geothermal drilling.

Abstract: Due to the sustainable development of river system has been threatened, as the ecological function was decayed; more attention has been paid to the improvement of ecological environment, one prominent example is the river regulation and its environment construction. Besides flood protection, river can also create the plentiful habitat and unique regional culture by optimizing river regulation pattern. Therefore, the research on how to restore damaged river ecosystems to healthy status has become one of the important environmental issues urgent to be solved. Functional regionalization is the prerequisite for appropriate restoration, which can provide scientific basis for the goal of ecological restoration. In this paper, the Songhua River in Harbin is selected as a study case. Based on the theories of ecological function regionalization and the current situation of the Songhua River area, four-dimensional structure planning on the spatio-temporal scale of river corridor is developed in this paper, including longitudinal, lateral, vertical and temporal dimension. Considering the Songhua River area has typicality of characters in different time, with distinct four seasons, and the winter is very long, a detailed study and deeply analysis is discussed, then, measures for restoration and management are put forward.

Abstract: The well drilling work of regional water exploration fighting against drought has characteristics such as tight schedule, heavy task, and wide span of working area. Therefore, in the process of actual water exploration, Hydrogeological method plays a crucial role. Skillfully using this method can save time, speed up the progress of fighting against drought and solve the water utilization problem in drought regions as early as possible. It also has characteristics such as low cost, quick effectiveness, high rate of well completion and so on. This paper sums up the examples occurred in actual work and proves the importance of hydrogeology comprehensive analysis in this battle against drought, providing important theory basis for water exploration work of large scope and high strength in battle against drought in future.

Abstract: In this paper, the stochastic differential equations theory was used to analyze the uncertainty of flood forecasting in river channel based on the forward algorithm of linear characteristic. And then a river channel flood forecasting model, in which the coefficient of storage and discharge was regarded as a random variable, was built. The statistical characteristics of outflow process could be taken part in theory by the built river channel flood forecasting model when the coefficient of storage obeyed a kind of normal distribution. Storage coefficient is random variable in the model. The results showed that the uncertainty degree of outflow process could be made through considering the uncertainty of river channel flood forecasting, which would provide some references for making decision in flood control.

Abstract: The Qinghai-Tibet Railway(QTR) is the highest and longest plateau railway in permafrost region in the world. The Qinghai-Tibet Railway in permafrost area locates in the hinterland of Qinghai-Tibet Plateau, which belongs to a low latitude, high altitude permafrost area. In this area, that the poor thermal stability, high ice content, and many other complex factors seriously impacts survey and design of The Qinghai-Tibet Railway. Permafrost is a special soil, it has many features different from the ordinary soil. And permafrost thawing layer has seasonal freezing-thawing process every year, along with a few of adverse geological phenomenon, which results in a series of engineering problems. This paper introduces the basic characteristics of permafrost along Qinghai-Tibet Railway, expounds the permafrost hazards of railway engineering, such as frost heaving, freeze thawing, frost boiling of roadbed, thaw collapse and mud flow, bridge foundation frost heaving and thaw settlement, deformation and cracking, culvert foundation freeze-thaw deformation, tunnel lining frost heaving and so on. Briefly analyzes the influence mechanism of permafrost to railway engineering. And then, proposes a temporary prescript for the railway engineering in different type of permafrost area. It is that each engineering in different area has to adopt different design concept and different prevention measures. At last, proposes the prevention measures and suggestions for the railway engineering in the permafrost region, such as reasonable control of embankment height, rubble air-cooled embankment, crushed stone slope protection with thermal insulation subgrade, heat pipe subgrade, ventilating pipe subgrade and so on.