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Takaaki Wajima Tomoe Shimizu Yasuyuki Ikegami 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(6):921-927
BACKGROUND: This study aimed to investigate the synthesis of zeolites from paper sludge ash (PSA) with added diatomite to remove both NH4+ and PO43? for water purification. The PSA had low Si and significant Ca contents. Four types of diatomite: white (T‐W) and brown (T‐B) from deposits of marine origin in Takanosu, and white (S‐W) and gray (S‐G) from lacustrine deposits in Shonai, were added to NaOH solution to increase the Si content and thereby synthesize zeolites with high cation exchange capacity (CEC). RESULTS: The order of the amounts of Si extracted from the diatomite to the alkali solution was S‐W > T‐W = T‐B > S‐G, which correlates with the amorphous SiO2 content of diatomite. The original ash without addition of diatomite yielded hydroxysodalite with CEC of about 1.0 mmol g?1. For all samples, the addition of diatomite to the solution yielded zeolite‐P with a higher CEC, but the addition of excess Si inhibited the synthesis of zeolite‐P, and the CEC of the product was low. A product with high CEC including zeolite‐P was obtained in a solution with around 500 mmol L?1 of Si concentration, and had the ability to remove both NH4+ and PO43?. CONCLUSION: Diatomite has the potential for used as an additive for the synthesis of high CEC zeolite from PSA. The product with zeolite‐P exhibited relatively high CEC, capacity for NH4+ uptake, and the ability to remove PO43? by precipitation, which is preferable for water purification applications. Copyright © 2008 Society of Chemical Industry 相似文献
104.
Mechanical properties and thermal stability of epoxy foams filled with white and black rice husk ash were studied. Epoxy foams were prepared from a commercial system and filled with different amounts of both the ashes (0, 6.8, 12.8, 18.0, and 22.7 wt %). The incorporation of both the ashes modified the final morphology of the foam, decreasing the average cell size and increasing the number of cells per volume unit. For all filler percentages used, the specific modulus and strength results showed that the white ash is more effective as reinforcing agent than the black ash. The initial degradation temperature was not affected by the content and type of ash used as the filler. The integral procedure decomposition temperature, weight loss, and char residue results were related to the ash type and atmosphere used in the thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献
105.
亟待理顺我国的煤炭安全生产管理体制 总被引:5,自引:2,他引:3
我国煤炭生产安全形势严峻,需要政府加强安全生产管理。多重机构的管理模式是否就是加强了安全管理值得探讨。从调研中发现,现行分散的行业管理体制结构分解了煤矿的安全生产责任,鉴于煤矿安全生产的技术性很强,精简管理机构、强化职能责任是煤矿安全管理改革的目标,重视管理科学的实践应用,理顺煤炭生产安全管理体制迫在眉睫。 相似文献
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In the world energy about 26% of all was dedved from coal combustion. Nearly 80% of the electricity produced in China is generated from coal. Coal will play the most important role in the coming 50 years as the past century in China. However one consequentially of the mining and combustion of coal is the mobilization of trace elements, especially trace metals, which have environmental and human health significance. Information on concentrations and distributions of potentially toxic elements in coal, and information On the modes of occurrence of these elements and the relations of the minerals in coal can help to predict the behavior of the potentially toxic trace metals dudng cleaning, combustion, weathering, and leaching. 相似文献
108.
Composition and morphology of char particles of fly ashes from industrial burning of high-ash coals with different reactivity 总被引:1,自引:0,他引:1
A comparative investigation of the composition and the morphology of char particles was conducted: char particles were recovered from fly ashes of two power stations in Russia from burning of high- and low-reactivity high-ash coals; the known results of studies of char particles generated in laboratory conditions from coals characterized according to the ASTM D388-98a standard were also used. The composition of organic and mineral components of different fraction char particles was studied. An inverse correlation between the content of the organic substance and the iron content in char particles was identified. The morphology of the char particles for the three main types (Cenospheric, Network and Solid) and the influence of coal reactivity and temperature on char morphology were investigated. The morphology of the mineral component of char particles of the two varieties of coals was also studied. It was shown that the high-temperature of industrial burning of Ekibastuz coal results in melting of the mineral substance and forming of micron-scale microspheres located in the lamellar porous structure of the carbon matrix. 相似文献
109.
Çan, Çatala?z?, Seyitömer and Af?in-Elbistan thermal power plant fly ashes were used to investigate the sintering behavior of fly ashes. For this purpose, coal fly ash samples were sintered to form ceramic materials without the addition of any inorganic additives or organic binders. In sample preparation, 1.5 g of fly ash was mixed in a mortar with water. Fly ash samples were uniaxially pressed at 40 MPa to achieve a reasonable strength. The powder compacts were sintered in air. X-ray diffraction analysis revealed that quartz (SiO2), mullite (Al6Si2O13), anorthite (CaAl2Si2O8), gehlenite (Ca2Al2SiO7) and wollastonite (CaSiO3) phases occurred in the sintered samples. Scanning electron microscopy investigations were conducted on the sintered coal fly ash samples to investigate the microstructural evolution of the samples. Different crystalline structures were observed in the sintered samples. The sintered samples were obtained having high density, low water adsorption and porosity values. Higher Al2O3 + SiO2 contents caused to better properties in the sintered materials. 相似文献
110.