Advanced Materials Research Vols. 113-116

Abstract: Constructed wetlands are very useful for the removal of nutrients from treated municipal wastewater. Use of different kinds of media and macrophytes improves the efficiency of nutrient removal of constructed wetlands. Three different media (pulverized ash bricks, shale and gravel) and common reed (Phragmites spp.) were used for present research work. This macrophyte is a local weed and easily available. Uses of different media with macrophyte are very efficient for nutrient removal from treated municipal wastewater. Out of these three media used for present research pulverized fly ash bricks media was most efficient for removal of phosphorus in constructed wetland.

Abstract: The belt conveyor is a transporting machine by friction in a continuous manner. The two order helical gearing reducer may be generally used as conveyor transmission, and can reduce speed and increase torque of belt. The objective function may be specified that that total center distance of the reducer incline to minimum, so the optimization model including the property and boundary constraints is created. Then the objective function with penalty terms is converted by penalty strategy with addition type, so as to transform the constrained optimization into the unconstrained optimization model. Considering the problem of low efficiency and local optimum caused by standard optimization methods, the simulated annealing algorithm is adopted to solve the optimization model of Belt Conveyor Transmission, and neural network method is applied to fit relative coefficient, then BFGS Quasi-Newton method is recalled automatically when the setting working precision is achieved again. So that the optimization process is simplified and global optimum is acquired reliably.

Abstract: We isolated flocculants-producing bacteria F2 from soil. It shows high and stable flocculating activity for Kaolin clay suspension. In order to increase yield of flocculants, we need determine the optimal obtained time. We measured the changes of several parameters using shaking flask experiment, including flocculating- rate, the content of polysaccharide, protein and glucose. It’s showed that the optimal obtained time of bio-flocculants is 21 h. And we built the model about the production of bio-flocculants. Through the comparison of experimental data and the corresponding calculated values from the models, we found that the data joint well and the model can provide theoretical basis for Industrialization of bio-flocculants.

Abstract: As a non-market good, the value of irrigation water can be approximated by empirical investigations of farmers’ willingness to pay (WTP) for irrigation water. In this paper, a contingent valuation study on farmer WTP for irrigation water was conducted. With double-bounded bidding, an average WTP of 1021 RMB/ha/yr was found. The perceived value of water is falls short of the costs of irrigation water provisioning. This suggests that the use of irrigation water in Zhangye is not sustainable, and the price policy alone may not serve the purpose of efficient irrigation water management.

Abstract: Explores empirically the formative factors of the scenic quality concerned with highway landscape evaluation. Based on earlier works the formative factors are comprehensively considered and summed up. Then EFA (exploratory factor analyses) and CFA (confirmatory factor analysis) are made by way of 112 questionnaires, which have all been completed and returned to develop a 6-dimensional model to reveal the scenic landscape beauty. Fitting the model by introducing SEM (structural equation modeling) the formative factors are verified including the six scenic quality aspects as follows: vividness, variety, cultural, naturalness, comfort and security.