Papers by Keyword: Waste Treatment

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Authors: Xiao Ming Lv, Xiao Ming Li, Jing Yong Liu
Abstract: With the continuous improvement of our environmental monitoring system, environmental monitoring laboratory has actually become the typical small pollution sources, which caused very prominent environmental pollutions. However, the pollution problems in the environmental monitoring laboratory are basically in the neglected state and without the standardized management. The paper analyzed the common polluted emissions and characteristics about the process of environmental monitoring in the laboratory. How to reduce laboratory contamination from the sampling, chemical analysis and monitoring processes was discussed. The main pollution problems were caused by the lack of laboratory environmental awareness and the laboratory contamination control at the expense. In conclusion, strengthen the environmental monitoring laboratory management and environmental education, recycling the laboratory waste, separating collection, and treating by different methods are the main ways to solve the pollutions in the Lab. The monitoring departments at all levels must improve its environmental quality in order to reduce the environmental pollutions and make efforts to avoid the pollution of the monitoring laboratory waste.
Authors: Wei Ting Lin, Ta Yuan Han, Yuan Chieh Wu, An Cheng, Ran Huang, Tsai Lung Weng
Abstract: This study investigates the properties of cement-based composites with addition of various recycled rock wools and compare with the properties of composites containing fly ash and ggbs. The use of recycled rock wool is with a cylindrical and fiber-shape particle less than 75 μm. Based on the chemical composition and particle size distribution, the material properties of recycled rock wool are similar to other pozzolanic materials such as fly ash and ggbs and can be use a supplementary cementitious material. The experimental results show that partially replacing cement with recycled rock wool improves the compressive strength and porestructure, but reduce the flow spread at the high level replacement. Therefore, the test results indicate that recycled rock wool is an effective mineral admixture, with 10 % to 30 % as suitable replacement ratio of cement for the difference water/cementitious ratios.
Authors: Shin Yoo, Ki Hyeon Moon, Seong Yoon Hyun, Seo Kyung Won, Geon Shin
Abstract: An experimental approach has been used to investigate the charateristics of silicon type powders using heat source of thermal plasma. In this paper, laboratory scale furnace (0.0529m3) using non-transferred hollow thermal plasma torch (150kW) is applied for the rapid melting and the impurities components volatilization. The components and the crystallization behavior of silicon type raw material for complete melting using in-flight melting technique with continuous powder feeding (500~1000 g min-1) into the furnace are investigated by changing the melting atmosphere. The determination of impurities absorption and erodability of the furnace caused by the extremely high localized tempeartures of plasma heat source and molten material is also followed.
Authors: Yan Hai Shao, Ming Ming Li, Xiong Tong
Abstract: Under the premise of comprehensive recycling valuable metals, a novel technology was developed to extract vanadium from spent Al2O3-based catalyst. Mixture of spent catalyst and sodium carbonate was roasted at 1000°C for 30 min with the mol ratio of Na2O to (Al2O3 + V2O5 + MoO3) as 1.15, after water leaching, 97.3% of vanadium could be extracted. With CaO addition of 25 g/L and reacting at 90°C for 4 h, 98.6% of vanadium in sodium aluminate solution was precipitated as desilication residue. The desilication residue was leached at 80°C for 45 min with sodium bicarbonate concentration of 100 g/L and L/S of 4 mL/g, over 96.4% of vanadium could be leached. By two purification steps with addition of 30 wt.% H2SO4 and Mg(NO3)2, respectively, over 99% of Al, 96% of Si, 93% of P and 95% of As were removed from leach liquor. Adding 50 g/L NH4NO3 to the purified leach liquor and adjusting pH to 8.2, 99.8% of vanadium could be precipitated as ammonium metavanadate. After calcination, the purity of V2O5 product was 98.25%. In the whole process, up to 88.7% of vanadium could be recovered from the spent catalyst.
Authors: Z. Zarina, Noorulnajwa Diyana Yaacob, A.M. Mustafa Al Bakri, C.M. Ruzaidi
Abstract: Effective Microorganism (EM) technology was found as the credible solution to solve many environmental problems including wastewater issues. The EM which is in the form of EM mud ball was tested to be effectively used for waste treatment that comes from the factories, resident area, and also agriculture sector. Furthermore, the polluted rivers can also being applied with this product in order to improve the water quality. Until today, the halal issues caused by the ingredients of EM still are not clearly mentioned by the manufacturer and becomes a concerns to most of the Islamic country like Malaysia. As the solution, halal based source are suggested in utilization of Effective Microorganism (EM). The result of the experiment shows that EM mud ball has the potential to solve the problem regarding treating the wastewater as it positively reducing the level of turbidity.Keywords: Effective microorganism (EM), Halal based sourced, turbidity, waste treatment
Authors: Yu Qing Zhao, Jin Li, Guang Qi Zhou, Chang Jian Liu, Kun Ma
Abstract: In the paper, we investigated the adsorption of nickel by nickel-resistant strain screened in our laboratory. Results indicated that at the following conditions: pH=6, initial concentration of Ni2+ was 25mg/L, mass concentration of bacterial strain was 3g/L, adsorption approach an equilibrium after 2h,and Ni2+ removal reached up to 98.2%. Simulation of adsorption by thermodynamic models revealed that Langmuir equation can describe the adsorption process well, which showed that the adsorption was carried out mainly by means of surface adsorption. AFM detections indicated that the mycelium showed a tendency of shrinking and assembling after the adsorption, which illustrated that the adsorption mainly occurred on the surface. Meanwhile, the surface adsorption can not rule out a certain extent, affect the joint adsorption occurs in the intracellular. After Ni2+ entered the extracellular polymers and even inside the cells, the adsorption was controlled, especially in the later period.
Authors: Yan Hai Shao, Ming Ming Li, Xiong Tong
Abstract: Based on X-ray phase analysis and exploratory experiments, a novel process was proposed to recycle multiple valuable metals like Al, V, Mo, Ni and Co from spent Al2O3-based catalyst. The spent catalyst was roasted by adding sodium carbonate with certain mol ratio, after water leaching, Al, V and Mo could be extracted into leach liquor, whereas Ni and Co were enriched in the leaching residue. V and Mo were precipitated in step from leach liquor by adding CaO and BaAl2O4, respectively. After removal of V and Mo, Al(OH)3 was prepared from sodium aluminate solution with carbonation decomposition process, and the purity of Al2O3 is 99.98%. With sodium bicarbonate leaching-purification-precipitation-calcination process, V2O5 could be prepared from V-bearing residue. Ni and Co were leached from water leaching residue with sulfuric acid. Recoveries of Al, V, Mo, Ni and Co from spent catalyst are 87.0%, 88.7%, 92.1%, 97.8% and 98.6%, respectively.
Authors: Zhuang Yuan, Xiao Xiang Zhao, Mei Hua Zhou
Abstract: Keratin sponge film was prepared from feather reduction residues, and influence of glycerol content on film’s characters and removal of aerosol were investigated. With increasing glycerol content, the elongation at break, porosity and air permeability increased together with looser structure of the film, while the inhalable particles removal rate decreased. The tensile strength increased when the glycerol content was below 5%, while the glycerol content exceeded 5% decreased. The film with 5 % glycerol content showed the best mechanical character, thermostability and flexibility. The air permeability was 368 mm/s, film's removal rate of PM10, PM2.5 and PM1.0 were 98.3 %, 39.28 % and 32.97 % respectively in air speed of 1 m/s. As a material made from natural resources, it was highly affinitive and had great potential in mask manufacture.
Authors: Chun Fang Lai, Guo Liang Zhang, Xin Jiang Sheng, Hai Min Sun, Lu Sheng Xu, Jin Zhe He
Abstract: Novel membrane contactors offer a number of important advantages over conventional dispersed phase contactors, including absence of emulsions, no flooding at high flow rates, no unloading at low flow rates, no density difference between fluids required, and surprisingly high interfacial area. Based on the former work of our group, this paper provides a general review of recent progress in the application of hollow fiber membrane contactors in liquid/liquid and gas/liquid separation and in the environmental waste treatment including VOCs and CO2 separation, metal ion recovery, and alcohol purification.
Authors: Kenji Yamaguchi, Kazuo Ogawa, Tsuyoshi Fujita, Yasuo Kondo, Satoshi Sakamoto, Mitsugu Yamaguchi
Abstract: Cutting fluid is commonly used during metal cutting process for cooling and lubrication. Fluid types are generally classified into mineral or fatty oils and water miscible oils. In Japan, the former is called water-insoluble coolants, and the latter is called water-soluble coolants. Water-insoluble coolants are specified as dangerous material by the Japanese law due to its flammability. Therefore, the water-insoluble coolants are not appropriate for unmanned operation of machine tools. Therefore, the usage rate of water-soluble coolants is increasing. Water soluble coolants are diluted with a water by several ten times. The waste management of the water-soluble coolant become important for environment-conscious green manufacturing. We have been developing a recycling system for water-soluble coolants. In the recycle system, water is extracted from the waste coolant and the water is then reutilized as a diluent of a new coolant. We have developed various types of chemical or bio-chemical water recovery methods for recycling systems. We found a commercially available amine-free water-soluble coolant is suitable for the recycling system. The processing time, processing cost, and the biochemical and chemical oxygen demand of the extracted water are improved by the amine-free water soluble coolant compared with a conventional amine-containing coolant. However, its corrosion inhibition performance was poor in general machining applications. Our cooperative company developed a prototype of a corrosion-inhibition-improved amine-free water-soluble cutting coolant. The prototype coolant showed a good stability and cooling and lubricating performances, and its recyclability was as good as that of conventional amine-free coolants. In this study, we focused on repeated recycling of the prototype coolant. We repeatedly applied the water recycling process to the recycled coolant. The recyclability of the prototype coolant was not affected by repeated recycling; however, process residues increased with the number of recycles, and a deterioration was noticed in the corrosion-inhibition performance of the coolant diluted with recycled water.
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