共查询到18条相似文献,搜索用时 781 毫秒
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采集某焦化厂废水处理系统的数据,选取当前常用的3种焦化废水处理技术和该焦化厂现用废水处理技术建立了较为完整的模糊综合评价数学模型,选择技术综合评价的评价因素集,利用判断矩阵分析法确定各评价因素的权重,建立了各定量因素指标的隶属函数,确定了各定性因素指标的模糊评语集,最后以模糊矩阵的合成运算完成模糊综合评价.4种焦化废水处理技术的综合性能优劣次序为:该焦化厂现用废水处理技术>普通活性污泥法>湿式催化氧化法>多相光催化氧化法. 相似文献
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Structural investigation of catalyst deactivation of Pt/SDB for catalytic oxidation of VOC-containing wastewater 总被引:2,自引:0,他引:2
The stability of styrene-divinyl benzene copolymer (SDB)-supported Pt (Pt/SDB) catalysts for destruction of volatile-organic-compound (VOC) in wastewater was examined. The test reaction was wet oxidation of water-containing aliphatic alcohol and formaldehyde at 140 degrees C and 90 psig for 40 h. The catalytic performance tests indicated that activity of the Pt/SDB catalysts could be maintained for VOC concentration of 3 wt.%, whereas the catalysts deactivated rapidly for 10 wt.% VOC containing wastewater. In order to investigate the nature of catalyst deactivation, extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge (XANES) spectroscopy were used to characterize the fresh and used catalysts. After the reaction, there is no oxidation of Pt clusters observed in EXAFS and XANES spectroscopy suggesting that the oxidation reaction takes places via the adsorbed oxygen. The spectroscopy results further indicated that deactivation of the catalysts were mainly caused by the increase of Pd particle size. After the reaction, the Pt-Pt coordination number has no significant change for the 3 wt.% wastewater whereas increase from 5.6 to 6.2 for 10 wt.% wastewater. Combined with the fact that the catalysts fractured during the reactions, we suggested that Pt agglomeration was mainly caused by thermal migration of the metal clusters. 相似文献
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Catalytic cracking of high-density polyethylene (HDPE) over fluid catalytic cracking (FCC) catalysts (1:6 ratio) was carried out using a laboratory fluidized bed reactor operating at 450 degrees C. Two fresh and two steam deactivated commercial FCC catalysts with different levels of rare earth oxide (REO) were compared as well as two used FCC catalysts (E-Cats) with different levels of metal poisoning. Also, inert microspheres (MS3) were used as a fluidizing agent to compare with thermal cracking process at BP pilot plant at Grangemouth, Scotland, which used sand as its fluidizing agent. The results of HDPE degradation in terms of yield of volatile hydrocarbon product are fresh FCC catalysts>steamed FCC catalysts approximately used FCC catalysts. The thermal cracking process using MS3 showed that at 450 degrees C, the product distribution gave 46 wt% wax, 14% hydrocarbon gases, 8% gasoline, 0.1% coke and 32% nonvolatile product. In general, the product yields from HDPE cracking showed that the level of metal contamination (nickel and vanadium) did not affect the product stream generated from polymer cracking. This study gives promising results as an alternative technique for the cracking and recycling of polymer waste. 相似文献
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Industrial wastewater is often contaminated with heavy metals and must undergo expensive and elaborate treatment. A new, environmentally friendly process, which allows both metals and water to be reused, has been developed. It comprises the following three process stages: firstly, a metal bonding agent (BA) is added to the wastewater to bind the heavy metal; secondly, the loaded BA is separated by ultrafiltration/microfiltration or a new hybrid process involving flotation and membrane filtration; and thirdly, the BA is regenerated. The first results from the characterisation of selected BAs (synthetic hydrotalcites and synthetic zeolites) in terms of their bonding kinetics, maximum loading capacity and regeneration potential are presented. 相似文献
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