Advanced Materials Research Vols. 726-731

Abstract: It is a key problem that when the temperature rise in seawater reaches balance under plants' thermal discharge. In the process of numerical simulation of Xiangshan Bay's temperature rise from plants' thermal discharge, TATR (Total Amount of Temperature Rise) was introduced as an index to help find the balance time. TATR shows its advantages of stability and reliability when compared with other indices such as volume. With TATR, it was found that the temperature rise reaches balance after 80 days' thermal discharge in winter while it takes 70 days in summer. Under thermal discharge of two plants, TATR at balance time is 1.77 (10⁹m³°C) in winter and 2.82 in summer. Under discharge of only Guohua Plant, it is 0.60 in winter and 1.56 in summer. Under discharge of only Wushashan Plant, it is 1.16 and 1.37 respectively. Based on the correct balance time, the temperature rise in nearby waters due to two major plants' thermal discharge was calculated, which provided useful data for researches such as water-environmental value loss.

Abstract: The thermal discharge from the Houshi power plant in China has been increased continuously with the increase in power supply. In order to understand the waste heat pollution conditions in the coastal areas of the Houshi power plant, we proposed a modified Princeton Ocean Model (POM) model to conduct three-dimensional numerical simulations for heat transport in the coastal areas of the plant. The proposed model has been verified to be valid in our previous study. This study employed the verified model to predict heat transport under the future operational conditions of the power plant with a thermal discharge of 217m³/s. The prediction results indicate that a larger area of waters near the plant outfall will have a temperature rise larger than 4°C, and this area of temperature rise is close to the water intake of the power plant. Besides, the heat accumulation phenomena will be serious in the depth direction and this will bring great influence to marine ecological environment, especially to benthic organisms. It is suggested that some measures are necessary to reduce temperature rise in the coastal areas of the Houshi power plant in the future.

Abstract: According to the pharmaceutical industry produce VOCs and stench of atmospheric environment pollution, combined with typical pharmaceutical biological fermentation and chemical synthesis process of VOCs and odour pollution are classified 4 types:fermentation tail gas, recycling of exhaust gas, exhaust gas and wastewater workshop stench. The control technology should be selected according to the four types of waste characteristics.

Abstract: When small gasoline engines using carburettor are operated in the plateau region, the air intake and fuel supply have different decrease with the altitude increase, and the mixture thicken and the emissions increase. Take outboard marine gasoline engine F15 as an example, the quantitative relationship comparing engines operated on the plateau region to on the plain in same mixing ratio are shown, which includes the power, specific fuel consumption, and CO, HC, NOx specific emissions. And fuel system correction methods are come out to meet EPA emission regulations in different altitudes.

Abstract: A pilot-scale WFGD experimental system has been built and employed to investigate experimentally operating parameters upon the water consumption of Wet Flue Gas Desulfurization (WFGD). The water consumption calculation formula of Calcium desulphurization system and water consumption rate curve on power plant WFGD system are obtained, according to the variation of coal can calculate the water consumption of the current conditions of FGD system, all this work has important significance upon FGD system operation on the current the variation of coal condition.

Abstract: Thermal conditioning (TC) can improve sludge mechanical dewaterability and drying performance, and produce solid fuel from sewage sludge with low-cost and harmlessness. This study investigates the influence of the TC on sludge combustion with thermogravemetric analysis of sewage sludge with/without TC. The experiments were carried out at a 150 mL/min air ambient with a heating rate of 10, 20, 30, 40, 50 °C/min. Tow integration approximation methods (Coats-Redfern and Flynn,-Wall-Ozawa) and a differential method (Kissinger method) were applied to study the kinetics. The Coats-Redfern method requires assuming the reaction’s kinetic mechanism. The calculated activation energy was lower than that from the Flynn-Wall-Ozawa and Kissinger, which were very close to each other. Among these methods, the Flynn-Wall-Ozawa can predict the energy required at every combustion stage, which therefore would be the best one to explore the combustion mechanism. The results show that the organic matters within sewage sludge are much more homogeneous after TC. The combustion of the thermal conditioning sludge (TCS) is much more stable with a 10% reduction in burnout time and a 9.94% reduction in combustion temperature range. The ignition temperature of the raw sludge keeps increasing from 188 to 224 °C with the heating rate, while that of the TCS is almost constant at 222-240 °C. The TC can improve the activation energy, which is about 144.52 and 123.00 kJ/mol for the raw sludge (RS) and TCS. Considering the gaseous pollutant emissions, the TC can dramatically reduce NO emissions, which is decreased from 14.22 to 6.59 mg/g by the TC, representing a reduction of 50.7%. Therefore, the TC can promote the hydrolysis of macromolecular organics, which would improve the sludge combustion performance, and reduce the gaseous pollutant emissions from combustion.

Abstract: Thermal degradation of organic pollutant was investigated in the presence of negative temperature coefficient resistor (NTC) under thermal treatments of 30°C, 35°C, 40°C and 45°C, respectively. Methylene blue (MB) was used as a model pollutant in this study. The degradation efficiency of MB in aqueous solutions were monitored by UV-vis spectrometry. Catalysts were allowed to adsorb MB to reach adsorption equilibrium before the degradation experiments were started. The results of degradation tests indicated that the best thermocatalytic ability was up to 41.68% in the concentration of 40 mg/L at 35°C within 30 h. Herein the feasibility of thermocatalytic elimination for organic contaminants with heat excitation was successfully demonstrated and the effectiveness of thermal catalyst adopted was also confirmed.

Abstract: The study focuses on Fe₂O₃ oxygen carrier for CO oxidation in chemical-looping combustion (CLC) system. Density functional theory (DFT) calculations were performed to detect the performance of Fe₂O₃ during CLC of CO. Reaction mechanism between CO and Fe₂O₃ was explored in details, which demonstrates that Fe₂O₃ with more low-fold O atoms on the surface could promote the activity of the Fe-based oxygen carrier in CLC system.

Abstract: Power sector is the major emitter in China of local air pollutants including SO2 and NOX, and CO2 and Hg with global environmental impacts. This study applied a bottom-up optimization model considering multi regional power grids in China to simulate how the local air pollution (LAP) control would shape the power generation mix before 2020 and estimate the mitigation potential of CO2 and Hg emission provided by LAP control. Results show that with LAP control targets, in 2020, 100% of coal-fired units need to be equipped with FGD or adopt in-furnace desulphurization for CFB; approximately 85% of coal-fired units should be equipped with SCR while the others retrofitted to be low NOX boilers. Compared to the scenario without environmental constraints, Hg emission decreases 46% while CO2 emission increases 0.64% in 2020 with LAP control targets. Control polices of local and global air pollutant emissions should be combined early in developing countries to obtain a cost-effective way for sustainable development.

Abstract: Based on the field measured results in the typical periods of flood season and dry season of Gucheng Lake, the present eutrophication levels of the lake were investigated by the Model of Butterfly Catastrophe, in which series of the environmental factors were considered including the ecological indicator of chlorophylla, the nutrient indicator of total nitrogen and total phosphorus, and the physical index of water transparency. The results showed that: the water eutrophication levels of Gucheng Lake were mal-distributed in space and time; the lake eutrophication tendency in flood seasons were more obvious than that in dry seasons; the eutrophication levels in the south part of the lake were relatively lower than that in the north and the average comprehensive mutation of fuzzy membership value in the south was about 0.3006 in the dry seasons. Due to the increased pollution load and the hydrodynamic conditions, the eutrophication degree in the estuary areas were higher and the fuzzy membership value was close to 0.235, achieving the medium eutrophication level.