Advanced Materials Research Vols. 518-523

Abstract: In the field of wastewater treatment and water recycling, Concentrates of NF and RO membrane process are the huge issue, which severely hindered wide application of NF and RO system. Therefore, the proper treatments of concentrates are needed. The current work reviewed the disposal method of the concentrates from four aspects: 1) discharge, 2) waste minimization, 3) innocuous treatment, and 4) recycling. The prospects of disposal of concentrates were also analyzed. To some extent, concentrates from NF or RO membrane are the valuable resources. In the further, exploring suitable and highly effective technologies to utilize concentrate as resources is promising.

Abstract: It is significant to realize stable operation of the simultaneous low dissolved oxygen coupled with low F/M system. Two acclimation modes including 1) reducing DO firstly and then adjusting the F/M , and 2)reducing the F/M firstly and then adjusting DO were conducted. The results showed that the first operation mode was prone to induce high-viscosity sludge bulking at the reaction temperature of 9~10°C and filamentous bulking under low F/M of 0.08~0.1kgCOD/kgMLSS•d at 20±1°C。However, good settling performance and effluent were achieved under the second operation mode. It is proposed to culture limited-mineralization activated sludge with higher-concentration to realize the prevention of sludge bulking.

Abstract: ZnO/AC composite was prepared from spent catalyst of vinyl acetate synthesis by using conventional thermal treatment under CO2 atmosphere. The final composite was obtained with the operating conditions of activation temperature of 950°C, activation time of 120min and the CO2 flow rate of 600ml/min. The structure and surface properties of the ZnO/AC composite were observed and characterized by scanning electron microscope (SEM-EDX), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and the UV diffuse reflectance spectra. It was found that the zinc acetate present in the spent catalyst is transformed to zinc oxide (ZnO) after thermal treatment. ZnO particles were well adhered and uniformly distributed onto the carbon surface, forming ZnO/AC composite. The thermal treatment of the spent catalyst gives rise to a material with excellent adsorptive and photocatalytic properties.

Abstract: HY zeolite showed better catalytic activities than FCC in the catalytical degradation of pyrolytic oil. This conclusion can be got through the evaluation experiment. HY zeolite catalysts were chosen to study the influence of operating conditions in the degradation of pyrolytic oil with different raw material concentration, reaction temperature and the amount of catalyst. Through the orthogonal test, the optimal conditions were got as follow: the reaction temperature was 450°C, the pyrolytic oil concentration was 30wt.%, and the amount of catalysts was 3g.

Abstract: This paper introduced the analysis of theory and practice using the slag cementitious material without cement clinker instead of cement. The experiment includes that fine out the better ratio of the slag cementitious material firstly, secondly use these materials to solidify the soil. The aim of the experiment is that the solidified soil with the material can meet the requirement of engineering in practice, in order to replace the traditional cement-soil and lime-soil used in engineering nowadays. Eventually, the strength of the paste block achieved 47.89 Mpa, the strength of the solidified soil achieved 5.01Mpa.

Abstract: Expansive hydration products of circulating fluidized bed combustion (CFBC) ash with different finesses are investigated in this paper. The results show that expansion occurred in hardened paste of CFBC ashes is mainly due to formation of dihydrate gypsum and ettringite. Besides, the free lime does indirectly cause expansion due to its effects on crystallization of ettringite. It also has been observed that linear free expansion rate of paste with ground CFBC ash is higher than that of paste using original ash at 1 day of hydration, but lower than paste with original ash 3 days and longer period of hydration later.

Abstract: In this treatise one-dimensional mathematical model of gas migration in multi-layered landfills of MSW on seepage mechanics of multi-pore media and Darcy’s seepage law. Analysis of gas migration in multi-layered landfills is carried out for three different cases. The gas pressure distribution characteristics in multi-layered landfills of MSW, the effects of final/internal soil cover, the permeability and thickness of the final soil cover, the permeability and gas generation rate of MSW on the gas pressure distributions are investigated. Results show that the bigger is the ratio of gas generation rate to gas permeability of MSW, the bigger is the gas pressure in a uniform MSW landfill. The gas generation rate of MSW mainly controls the size of gas pressure, and the gas permeability of MSW dominates the gas pressure distribution characteristics in a uniform MSW landfill with a final soil cover. The smaller is the gas permeability of the final soil cover or the bigger is the gas generation rate of MSW the bigger is the gas pressure gradient inside the final soil cover

Abstract: Based on the energy recycle ideas, in view of the three-level green supply chain (GSC) including a manufacturer, a processor and a collector, the manufacturer-leading Stackelberg models were established with random recycling. The rewards and punishments contract between the manufacturer and the processor was designed, and the influences of the proposed mechanism to the game parties’ optimal strategies were discussed. The research shows that implementation of the rewards and punishments mechanism is effective to improve the effort-level for recycling end of life (EOL) product, and increase the processing rate of EOL product. The conclusions are helpful to guide the formulation and implementation of the strategy of sustainable development in China nowadays. In addition, the research has great realistic significance for instilling the consciousness of environmental protection.

Abstract: When acetophenone are used or synthesized in the Laboratory, a lot of waste effluent containing acetophenone will be produced. If the untreated waste effluent is discharged, it will pollute the environment seriously. According to comparing a few treatment methods of acetophenone, the best way to treat containing acetophenone waste effluent is oxidation method by concentrated nitric acid.

Abstract: The jet temperature of the plasma generator for waste disposal reaches as high as 10000K so that it is difficult to measure directly. By constructing a digital plasma measurement system, the operating parameters of plasma generator can be precisely controlled and measured. According to energy balance principle, the mathematical model was determined to calculate the average enthalpy at the plasma generator exit plane, and the average temperature and its distributions were obtained. Influence of different gas compositions on plasma jet characteristics was studied. The results show that, at the plasma generator exit plane, the maximal temperature and average temperature of argon plasma jet is about 18794K and 10193 K respectively, while that of argon-hydrogen plasma jet is about 22358 K and 12100 K.