Applied Mechanics and Materials Vols. 71-78

Abstract: Due to increasing water scarcity, reclamation and reuse of the secondary effluent of wastewater treatment plant are widely concerned in many countries. Before reuse, the residual contaminant in the secondary effluent should be further removed to guarantee safe reuse. Coagulation/sedimentation and subsequent chlorine dioxide(ClO₂) disinfection was adopted for tertiary treatment of secondary effluent. Selection of coagulant and optimization of tertiary treatment parameters were performed in this study. The results showed that coagulation could remove turbidity and total phosphours(TP) effectively. Polyaluminium chloride(PAC) was the most suitable coagulant. The optimal coagulation condition was as follows: PAC dosage of 10mg/L(measured as Al³⁺), reaction time of 20 min, settling time of 40 min, in this case, the average removal rate of turbidity, color, UV₂₅₄, TP and TOC could reach to 58.2%, 22.8%, 18.2%, 60.6% and 22.2%, respectively. ClO₂ could inactive bacteria and E. coli effectively. ClO₂ could further remove UV₂₅₄, color and TOC. In case of ClO₂ dosage of 5mg/L, the sterilization efficiency could reach 100%, and the removal rate of UV₂₅₄, color and TOC was higher than 25%, 70% and 25%, respectively. In the optimal condition, the removal efficiency of residual contaminant by the combination process was as follows: UV₂₅₄ of 45.9%, color of 76.5%, TOC of 66.7%, turbidity of 61.9% and TP of 96.3%.

Abstract: The removal of NO_x in simulated flue gas was studied using urea/ potassium permanganate solution with different concentrations as absorbent. Experiments were carried out in a packed absorption reactor filled with steel pall rings at about 70°C. The effect of amount of urea, amount of potassium permanganate, effective height of absorption solution and addition of SO₂ on denitrification efficiency was examined. The results show that a high removal efficiency of NO_x can be attained using urea/ potassium permanganate solution process, In the solution of 5% urea and 600mg/L potassium permanganate, the removal efficency of NO_x could be achieved 91.5%. Increasing the amount of potassium permanganate and the effective height of absorption solution could improve denitrification efficiency remarkably. Whereas, no obvious improvement in NO_x removal efficiency was observed when increasing the amount of urea without potassium permanganate. The adding of SO₂ resulted in a decline of denitrification efficiency.

Abstract: The selective catalytic reduction of nitric oxide by ethylene was studied over Cu/ZSM-5 catalyst in the temperature range of 200-550°C, in which NO cannot be reduced by ethylene without Cu/ZSM-5 catalyst. Prepared Cu/ZSM-5 catalyst in varies loading as Na/ZSM-5 by the wet impregnation method, and the effect of the catalytic activity was studied in varies fitting temperatures. Several influencing factors, such as the different reaction temperatures, oxygen gas concentration, and Cu²⁺ concentration were investigated. Cu-Ce-ZSM-5 catalyst was prepared by wet impregnation method and the metallic influence of CeO₂ to the catalytic ability was studied.

Abstract: Energy and Coal Chemical Industry Base (ECCIB) is an important impetus of the development of regional economy, and it is also the guarantee of energy security of China. But, inevitably, the development of ECCIB causes the damage of the ecological environment, for the base is a collective place of many heavy industries. Environmental permit is considered to be one of the important source control measures. Implementing environmental permit in ECCIB has an extraordinary strategic significance for improving the quality of the regional environment and achieving sustainable development. The paper elaborates the concept and the connotation of environmental permit, and interprets the environmental permit of ECCIB from three aspects, namely policy level, environment level, and economic level. At last, the paper also gives some suggestions to its further development. All of these can help to promote the implementation of environmental permit of ECCIB in China.

Abstract: The paper studies the effects of the growth about summer maize on different ways of furrow irrigation and Processing of water. The results showed that controlled alternative furrow irrigation can effectively inhibit the growth of maize redundancy, so that is conducive to production of photosynthetic to the formation of the direction of operation, irrigation and water consumption decreases, the yield unchanged. Reasonable control of water in the lower limit, controlled alternative furrow irrigation is suitable for water supply maize model.

Abstract: According to requirements of the natural and economic laws, the environmental management of watershed distinction is inevitable for improvement of watershed environmental management effect. In the paper, the Nine-division Principle is set forth, i.e. division by watershed, area, sequence, stage, type, grade, duty, right and policy through analysis of watershed distinction management in system theory and behavior economics, and of regional sub-characteristics of watershed in geographical elements, functions and economic developments. Under the guide of Nine-division principle, the idea on the environmental management of watershed distinction is reflected and implemented smoothly by dividing watershed environmental and economical function region, ways of optimizing the watershed environmental management, and creating conditions for implementation of environmental management of watershed distinction.

Abstract: The characters of photosynthetic bacteria and its action mechanism were simply described, And the research of using photosynthetic bacteria to treat eleven kinds of wastewater such as monosodium glutamate wastewater, citric acid wastewater, distillery wastewater, starch wastewater, bean products wastewater, Chinese traditional medicine wastewater, dye wastewater etc were discussed in detail in this paper. It was also pointed out that the photosynthetic bacteria will have a promising prospect in water pollution prevention.

Abstract: The dynamic property of a high-rise building structure and time-history analysis under earthquake were analyzed by using the finite element program ANSYS. A modal analysis of the tower was conducted and the first 20 frequencies and modal shapes were obtained. The displacements and inner force under the earthquake were calculated. The result showed that the structural stiffness was enough to sustain earthquake load; and the stiffness distributed equally. These results can provide reliable basis for structural design.

Abstract: Pentachlorophenol (PCP), metallic oxide and ball-grinder medium steel beads are ground together in a ball-grinder under room temperature and pressure to degrade PCP. A AgNO₃ standard solution was used to titrate the Cl^--containing solution made from grinding product. The dechlorination rate used to show the degradation result of PCP was calculated through the amount of AgNO₃ standard solution. The results show that dechlorination rate is increased with grinding time increasing, and the product shows a black hue after 2.5h grinding, which might be a sigh of elemental formation carbon; The bigger the CaO/PCP molar ratio is, the better the dechlorination rate is. With the molar ratio of 50:1,the dechlorination rate is over 90%, while 60:1 for almost 98%;

Abstract: Laboratory scale experiments were conducted to study the performance and characteristics of nitrogen (N) and phosphorus (P) removal of a sequencing batch moving bed biofilm reactor (SBMBBR) with simple anaerobic/aerobic operating mode. Experimental results indicated that, under the operating condition of influent N concentration of 114 mg/L and P concentration of 12 mg/L, N and P removal efficiency reached 95% and 94% respectively under the conditions of influent COD/N (C/N) ratio of 2.8 to 4.0. Track studies of N, P and other operating parameters demonstrated that N removal was accomplished by anoxic denitrification during the filling and mixing stage and simultaneous nitrification and denitrification (SND) process in aerobic stage, while removal of P was realized through conventional phosphorus removal and denitrifying phosphorus removal processes.