Advanced Materials Research Vols. 374-377

Abstract: Taiyuan is a city with more moutains, less loess resource and abundant coal gangue. This paper studied the feasibility of turning coal gangue into filling in Taiyuan region, based on successful experience home and abroad. A series of tests on physical-chemistry properties and mechanical characteristics of the coal gangue proved that coal gangue used in the experiment has good chemical properties, grain composition. The coal gangue is a kind of non-sticky coarse grained soils which can drain off water freely, and it can be used as the filling of foundation. Based on tests, this article provided a theoretical basis and a favorable reference for engineering application of coal gangue and its research and development in other areas.

Abstract: Combing with the concept of soft matter and demulsification mechanism of cationic asphalt emulsion, the authors analyzed mechanism of structure formation of cement asphalt emulsion mixtures; thought that minor dosages of cement make properties of asphalt emulsion concrete be changed greatly, and structure of the mixtures mainly results from structure of asphalt emulsion concrete and solid net structure made from asphalt emulsion particles and cement particles; put forward four functions of cement in structure formation of the mixtures, and discussed influence rules of two kinds of binding materials, cement and asphalt emulsion, on structure formation of the mixtures.

Abstract: Insulating materials were prepared by microsilica, silica aerogels and quartz fibers as raw materials, water glass as binder, and molded by the semi-dry method. In this paper, the effects of the addtion amount of silica aerogels on mechanical properties and microstructure of insulating materials were studied. X-ray diffraction (XRD) was used to characterize the phase composition and scanning electron microscope (SEM) was used to characterize the microstructure of the materials. The results show that when the silica aerogels content was at 40%, the material had the best properties in present study of true porosity of 45.9%, flexural strength of 5.0MPa and compressive strength of 37.9MPa, respectively.

Abstract: Lauric acid/stearic acid as the binary phase change materials, modified sepiolite as the inorganic carrier, organic/inorganic composite energy storage materials was prepared by melting adsorption.Comprehensive experiment results show that binary phase change material is lower than single one at initial phase change temperature and phase change peak temperature, and it has good energy storage results, the composite material can be used in energy storage and heat recovery system to save energy.

Abstract: In this paper, concrete incorporated organic fibers, i.e., polyvinyl alcohol fiber (PVA fiber), polypropylene fiber (PP fiber), cellulose fiber (UF fiber), polyethylene fiber (PETF) was produced. The properties measured included strength and crack resistance performance of the concrete. The effect of organic fibers on the crack resistance properties was investigated. Test results indicated that the organic fibers of different types could reduce the size and amount of crack source; organic fibers provided better enhancement for shrinkage resistance of concrete; Cellulose fiber concrete applied for secondary lining under the Ⅲ wall rock, both work performance and strength index satisfy the design demand, and concrete surface cannot detect crack after 280 days.

Abstract: with the raise and continuous development of the concept that the buildings should be Energy-saving, environmentally friendly and greening, it has enjoyed a more widely use and has been used in a large amount in building roads, squares and pedestrian roads and so on. But its performance of permeability keeps falling down in the process of been used in years, which have a bad influence in its working life. At the same time it is determined that its performance should be improved by its bounded ness of ecological function. This experiment applies nanometer TiO2 on behave of Neon semiconductor catalytic materials to pervious concrete. It can not only meet the requirement about its performance durability in a certain degree, but also highly improves its ecological function.

Abstract: The effect of temperature on two stage aged-refuse-based reactor which treats leachate in natural ventilation was investigated in autumn and winter. Results indicate that the average concentrations of COD in treated effluent increase from 726 mg/L in autumn to 2000 mg/L in winter in the first stage reactor while they are 246 mg/L and 1010 mg/L respectively in the second stage reactor. The average concentrations of NH3-N in treated effluent increase from 123.7 mg/L in autumn to 620 mg/L in winter in the first stage reactor while they are 123.7 mg/L and 620 mg/L respectively in the second stage reactor. Accordingly, the average removal rates of COD decrease from 81.7% of autumn to 73% of winter in the first stage reactor and decrease from 64.7% to 52% in the second stage reactor, and finally, the total COD removal rate in this system drops from 92.7% in autumn to 85.8% in winter. So we can conclude that the effect of temperature on the first stage aged refuse reactor is better than that on the second stage aged refuse reactor.

Abstract: Abstract.One superior iron and manganese bacteria were separated from the stable operation of porcelain granular BAF filters of removing iron, manganese and ammonia. The bacteria was domesticated at low temperature. By analyzing the sample water containing iron and manganese in the role of iron and manganese bacteria which was not domesticated and domesticated at different temperature, observing the Iron and manganese concentration with time going on, studying the bacteria’s removal of iron and manganese property and the domesticated effect. Studies show that: the selected bacteria with 1% bacterial liquid at proper temperature within 48h ,the removal rate of iron and manganese was 75% and 35% respectively;After domesticated at low temperature, the removal rate of the iron and manganese domesticated bacteria at 10°C was improved 0.4 and 2 times more than the before domesticated; The iron and manganese domesticated bacteria at 10°C did not grow at 4°C,but the bacteria’s removal rate was better than the bacteria cultured at 30°C,and the iron removal rate was improved from 23% to 35%,the manganese removal rate was improved from 5% to 11%.

Abstract: Difficult for low turbidity water treatment, the treated not reached the drinking water quality standards, the beaker coagulation has been set. In this experiment, the removal effects of low-temperature and low-turbidity water were investigated by using polyaluminum chloride (PAC) and modified active silicic acid. The results indicated that individual addition PAC turbidity removal rate was less than 80%. While adding 67 mg /L PAC and stirring 9-13min, then adding 20 ml /L modified active silica acid of 5% sodium silicate solution and 0.1% polyacrylamide solution with volume ratio of 15:1 and standing 5 min, the coagulant effect was the best and the turbidity removal rate was more than 90%. The optimizing keep time for modified active silica acid was 24 h.

Abstract: To improve treatment performance and alleviate membrane fouling, the physical and biological properties of sludge in combined MBR which divided into anoxic, anaerobic and aerobic zone were studied. During initial startup period, the sludge in A/A/O combined MBR was suspended growth, after textile carrier package, the sludge was suspended and fixed growth. The biomass analysis showed that with the increase of operation time, MLVSS/MLSS decreased from 0.93 to 0.72 which certified that high MLSS concentration caused biomass growth slow gradually, while packing textile carrier could supply attached biomass which maximum value was 0.18g/cm(3777.8mg/L). Meanwhile, high MLSS concentration also resluted in high sludge viscosity which could reach to 35.42mPa•s and decreased sludge activity. Particle size anaylisis showed that shear stress of aeration made the sludge flocs smaller than conventional activated sludge process. All the sludge properties which had been analysis in this study showed A/A/O combined MBR had great difference from conventional MBR process, and some parameters could be used for membrane fouling control in A/A/O combined MBR for wastewater treatment project.