Advanced Materials Research Vols. 1073-1076

Abstract: The experiment disposing waste water with dilute acetic acid aimed to recycle acetic acid and synthesize high value added n-butyl acetate with cetyl trimethyl ammonium bromide (CTMAB) as the phrase transfer catalyst. Over-dose n-butanol was added and n-butyl acetate was extracted with the mixed solution of trioctylamine (TOA) (20%,w) and tributylphosphate (TBP) (80%,w) as the extractant. After the still standing and liquid separation, the organic phase was depressurized and distilled under the pressure 25kPa.The n-butanol and a part of acetic acid were recycled, and n-butyl acetate was collected between temperature 70°C-75°C. The synthetic process parameters were optimized, that was: CTMAB 0.35g /0.127mol acetic acid, TOA/TBP 30ml, the ratio of alcohol and acid 1.3:1.0, reaction time 2.5h, reaction temperature 30°C.The extraction rate of acetic acid was 88.2%.The yield of n-butyl acetate was 81.3% and phrase transfer catalyst with extractant was recycled for 6 times whose effect was reduced a little but good enough. This experiment, which included esterification reaction with phase transfer catalyst and extractive distillation process, has received a satisfactory effect and can be used in similar system.

Abstract: The printed circuit board (PCB) in the electronic waste contains a variety of metals and organic materials, including bromine, heavy metals and other pollutants. Thermal treatment is an effective method for harmless disposal of waste circuit boards with resources recycle. In this study, the composition of RF4 type waste game PCB was determined by elemental analysis and proximate analysis, followed by thermogravimetric analysis of the weight lost process in CO₂、N₂ or air, at 10°C/min, 20°C/min or 30°C/min programmable heating rate, and the thermal decomposition reaction kinetics parameters were calculated with the Kissinger method. The results show that under the CO₂ atmosphere, the weight loss process of the sample consists of the 250°C～410°C and 750°C~960°C temperature intervals; under the N₂ atmosphere, the rapid weight loss stage is between 263°C and 420°C; under the air atmosphere, the weight loss process is from 178°C to 675°C, including three minor weight loss stages. The phenolic volatile components are mainly released around 260°C～360°C under three different atmospheres, while the residual carbon is further oxidized under the air atmosphere or gasified in CO₂ at temperatures above 800°C.

Abstract: Based on the development of the construction and demolition waste recycle, this paper expands comprehensive thinking and analysis on the current situation and problem of construction waste recycle supervision and management system. From business management, administration, economic and public opinion etc, this thesis proposes establishing sound construction waste recycle monitoring mechanism and providing the basic system guarantee for construction waste recycle.

Abstract: The high concentration and high acid organic waste liquid is treated by using the self-developed drum type cavitation impinging stream—micro electrolysis reactor. Under optimal conditions, namely iron-carbon ratio of 1: 1, each reaction time 3h, standing reflux for 2 times, first filler dosage 200g, successive half, controlling the pH value of less than 3. Waste liquid COD removal rate can reach 93.5%, and the biodegradability of the effluent B/C is more than or equal to 0.4. By comparing the treatment effect of cavitation impinging assisted and simple micro electrolysis, it is founded that COD removal rate is high by using cavitation impinging assisted micro electrolysis method the processing time is short, the water is good biodegradability lower production cost, convenient control and operation, with a higher value.

Abstract: A simple, fast one-step method was used to prepare graphene/SnO₂/citric acid (GN/SnO₂/CA) nanocomposites. Fourier transform Infrared spectroscopy, UV-vis adsorption spectroscopy, transmission electron microscopy, X-Ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy were employed to characterize as-prepared GN/SnO₂/CA nanocomposites. Furthermore, in the adsorption performance research, GN/SnO₂/CA nanocomposites indeed displayed excellent adsorption ability towards cationic dyes.

Abstract: This paper reports about a pilot-scale feasibility study of Advanced Treatment of Coking Wastewater with Biological Activated Carbon technology based on the better experimental data of laboratory scale test .The self-designed of the Biological Activated Carbon Aerated tower was based on the optimal operating conditions of the results obtained from laboratory scale test.The removal efficiency to pollutants of efficient compound bacterium is estimated in biological activated carbon process through the variation of COD concentration, chromaticity, and Contrast the total ion chromatogram and UV absorbance spectrum of effluent and inflow.The results of the pilot-scale test show that BAC technology may be a suitable option for the advanced treatment of Coking Wastewater. the efficient degrading strains can reproduce on the activated carbon quickly.Concentrations of COD and chromaticity in outflow water were at a lower level (with COD about 60mg/L and chromaticity about 50 degree), the average COD removal rate greater than 50% and chromaticity removal rate greater than 70%.

Abstract: The SPH method was introduced to simulate the centrifugal atomization process between molten slag and rotary disc since the traditional method based on grid cannot effectively solve the large deformation problem. Coupling the SPH method with FEM was realized through the coupled algorithm based on penalty function. The effectiveness of coupling algorithm used for calculating the centrifugal atomization process was affirmed. Under the condition that speed of rotary disc and molten slag flow are 1500rpm, 0.1m/s, respectively, the speed of molten slag particles that are directly colliding with the rotary disc is in a range from 2.5m/s to 3.0m/s as soon as that of molten slag particles disturbed by stress wave is in a range from 0.25m/s to 0.8m/s with the characteristics of volatility. This study is helpful for optimizing atomization process design and energy-saving efficiency.

Abstract: Batch tests were conducted to study the effect of internal carbon resource on the competition between phosphorus accumulating organisms (PAOs) and glycogen accumulating organism (GAOs) for simultaneous N and P removal. The result showed that the average P removal rate of PAOs was above 98.5%. Both PAOs and GAOs enriched sludge released P effectively on the anaerobic phase, and about 20 mg/L P was released. In the anoxic-P uptake process, 2.24 mmol/g-MLVSS and 2.44 mmol/g-MLVSS of polyhydroxyalkanoates (PHA) were consumed by PAOs enriched sludge and GAOs enriched sludge, respectively. Simultaneously, the glycogen concentration of GAOs enriched sludge was higher than that of PAOs enriched sludge during the anoxic process, on the contrast, more glycogen was synthesized in PAOs enriched sludge than GAOs enriched sludge, and 0.95 mmol/g-MLVSS glycogen was synthesized in PAOs enriched sludge.

Abstract: Constructed wetland is a new wastewater treatment technology. It not only is more effective in wastewater treatment, but also has good eco-landscapes value. According to the characteristics of domestic wastewater discharge in rural, constructed wetlands is a key technology to solving this problem in China. Application of constructed wetland to Chinese rural domestic wastewater treatment was reviewed in this paper. On this basis, the issues in the application of constructed wetland encountered, and future trends are discussed. On the one hand, constructed wetlands were prone to clogging and low nitrogen removal efficiency. On the other hand, some existing constructed wetlands were abandoned due to poor maintenance and management. Therefore, in order to play better the role of wastewater treatment, anti-blocking ability and denitrification efficiency of constructed wetlands should be improved. Meanwhile, the maintenance and management of constructed wetlands should be strengthened. Application of constructed wetlands in the rural area provides a strong guarantee for sustainable development of rural economy.

Abstract: Initial rainwater pollution is an important non-point source pollution of urban drainage systems. The application of storage tanks and other reduction facilities has play a key role in reducing first flush pollution. Because of the lack of scientific evaluation system, the evaluation is disorderly and there are many operational problems. This case is based on the reduction facilities research of Suzhou Creek in Shanghai, through which a standard evaluation system and implementation procedure are built to perfect the incomprehensive and unscientific system, so that the efficiency can be improved.