Advanced Materials Research Vols. 446-449

Abstract: The situation was analyzed in this paper about the wastewater treatment of the nylon chemical engineering. According to the types and characteristics of the industrial water, the processes were improved including cooling water, condensate water, desalination water and wastewater. The results indicated that the recycling efficiency was increased and the unreasonable emissions were reduced, which were beneficial to save water, reduce production costs and reduce pollution to the environment.

Abstract: The paper gives an overview on velocity models of iron release in water supply pipe at home and abroad, which incorporate empirical statistical models and dynamic models. Meanwhile, the characters of each iron release model are summarized. At last, the author analyzes the frequency of all parameters used in models mentioned in paper and puts forward the developing orientation on velocity models of iron release. The author also concludes that the establishment of velocity models of iron release is conducive to getting command of iron release in water distribution systems and guaranteeing the safety of potable water in drinking water pipe.

Abstract: By using the conventional activated sludge as seed sludge in SBR to cultivate the aerobic granular sludge system, the mechanism of nitrogen and phosphorus removal was explored. The results showed that the aerobic granular sludge system consisted of the heavy aerobic granular sludge and the light flocculent activated sludge was formed in the reactor after 15 days. The SVI of the aerobic granular sludge system was about 50ml/g～60ml/g, the MLSS was about 3000mg/L～4000mg/L steadily, and the weight ratio of granules in the total sludge was about 70%.The removal rates of NH4+-N, TN, and PO43-P in the anaerobic-aerobic operation mode were 80%～97%, 80%～97% and 70%～85%, respectively. It indicated that granules and flocs were beneficial nitrogen and phosphorus removal, respectively.

Abstract: Results of our workgroups have shown that carbon fibers (CFs) are high quality biofilm carriers with well biocompatibility relative to other polymer carriers used in biofilm sewage treatment. In the present study, two kinds of microorganisms, namely, aerobic nitrifier and facultative aerobic denitrifying bacterium, were immobilized on the surface of different CFs, which the effects of specific area, functional groups and wettability on immobilization of these bacteria was studied. Results show that different microorganism require for different surface properties of CFs. Biomass of immobilized aerobic nitrifier increases with increasing specific areas, surface oxygenic functional groups and wettability of CFs. It can be immobilized more facultative aerobic denitrifying bacterium if there are proper specific areas, surface functional oxygenic group and wettability on the surface of CFs

Abstract: With the deepening of urbanization, the urban water environment is dramatically changed. The flood peak emerges in advance and flood volume is more tremendous, which results in frequent urban flooding disasters. The increasing demand of fresh water intensifies the shortage of portable water. In combination with the requirements of sustainable building, we design the rainwater harvesting and reuse system in DSM (China) limited. Some structural BMPs measures, such as green roof, managed grass, cobble trench, pervious paving, vegetative swale, sedimentation and fiber filter, are utilized in this project. The treated runoff is reused for flushing toilet in buildings. The stormwater runoff, equal to 90% of the average annual rainfall in the development site, is captured or treated, and 80% of the average annual post-development total suspended solids (TSS) is removed, the rate of total water saving is 71.1%, runoff quantity of post-development is lower than pre-development. The stormwater is filtered and infiltrated to the most extent, which creates a good water environment and a beautiful landscape for the development site. The reduction of portable water utilization brings good economic and social returns for the water system. Additionally, the design is awarded gold of LEED-NC by LEED-NC core committee, which can be a demo project for sustainable building in Shanghai.

Abstract: A hybrid process of conventional treatment UF-BPAC (biological powder activated carbon addition on immersed ultrafiltration membrane bioreactor) was evaluated for the treatment of taste and odor in algal-rich water simulated. The results confirmed that in the immersed ultrafiltration membrane bioreactor PAC had sufficient adsorption and long-term biodegradation of dissolved organic materials which cannot be removed by ultrafiltration membrane alone. UF-BPAC processes could intensify the conventional treatment. Through the advanced treatment of UF-BPAC, the average removal ratios of DOC and UV254 increased 19.6% and 30% compared with the conventional treatment process, respectively. Perfect ammonia removal ratio (82.5±5.5%) was also recieved through hybriding the conventional treatment process and UF-PAC process. The major taste and odor compounds from the raw water, 2-MIB and geosmin both fell below the odor threshold, which guaranteed the effluent quality.

Abstract: The prestressing wires of prestressed concrete cylinder pipe (PCCP) provide concrete core with compressive stress to resist internal pressure. Broken wires resulting from corrosion and embrittlement may cause cracking in pipe wall and increase the risk of failure with time. By developing a simplified model to reveal the mechanism of circumferential cracking due to wire breaks in PCCP, the longitudinal bending of pipe wall is analyzed, and the maximum number of broken wires can be determined conveniently by the equations derived in this paper. Verification against results of finite element analysis shows that the presented method has decent accuracy which is not significantly influenced by effective pipe length and wall thickness. By comparing the calculated maximum number of broken wires with the actual number of broken wires detected by inspection and monitoring technologies, circumferential cracking in prestress loss zone can be predicted, thus aiding condition assessment of PCCP.

Abstract: Abstract. In order to promote the application of water-saving technology, to use natural resources effectively and to realize the sustainable development of our economy, we should explore and summarize the experience of water-saving for water supply and drainage and meanwhile create conditions for the design and layout of buildings and districts.

Abstract: A theoretical analysis of novel PV/T solar collector is presented in this paper. The collector is made of vacuum tube-PV sandwich and the heat extraction from PV panel by the water passing through u-shape cooper tube of the collector results in the reduction of the PV cells’ working temperature. This also improves the electrical and thermal efficiencies of the PV cells. Based on energy balance of each parts of the vacuum-tube-PV sandwich, mathematical models are developed to evaluate the energy performance of the PV collector and analyze its affecting factors. The simulation results indicate that the thermal efficiency increases slightly while the electrical efficiency decreases slightly with the increasing radiation. Both the thermal and electrical efficiencies increase by 1.4% and 0.23% respectively with every 10 kg/h increase in water mass flow, and decrease by 3.8% and 0.6% respectively with every 10 °C increase in inlet water temperature.

Abstract: Based on the characteristics of the mine tunnel and turbulence equation, the mathematical model of the mine tunnel of the ventilation flow is set up .Using the software simulates and analyzes the distribution of the velocity field of airflow and temperature field under different wind speeds in the mine tunnel. The result shows that the inlet airflow at the speed 4.5m/s is more stable and lower temperature to improve the working environment on the roadway.