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961.
评价了脂肪酸烷醇酰胺表面活性剂AF的界面张力和乳化性能,利用岩心驱替实验对其提高采收率效果进行了研究。结果表明,在模拟地层水的矿化度为5 119.63 mg/L时,AF浓度为0.2%~1.2%,其界面张力均能达到超低值;NaCl浓度为0.4%~2%,AF有效浓度为0.3%~0.6%时,体系的界面张力均能达到10-3mN/m数量级。AF具有较好的乳化原油的能力,在浓度为0.5%时,形成的O/W乳状液的稳定性最强,液滴粒径最小。岩心驱替实验表明,AF表面活性剂可在水驱基础上提高原油采收率20%以上,提高采收率效果明显,具有良好的应用前景。 相似文献
963.
《分离科学与技术》2012,47(16):2399-2407
A new phenol–formaldehyde based chelating resin containing 4-(2-thiazolylazo) resorcinol (TAR) functional groups has been synthesized and characterized by Fourier transform infrared spectroscopy and elemental analysis. Its adsorption behavior for Cu(II), Pb(II), Ni(II), Co(II), Cd(II), and Mn(II) has been investigated by batch and column experiments. The chelating resin is highly selective for Cu(II) in the pH range 2 ~ 3, whereas alkali metal and alkaline earth metal ions such as Na(I), Mg(II), and Ca(II) are not adsorbed even at pH 6. Quantitative recovery of most metal ions studied in this work except Co(II) is achieved by elution with 2M HNO3 at a flow rate of 0.2 mL min?1. A similar trend is observed for distribution coefficient values. The quantitative separations achieved on a mini-column of chelating resin include Cd(II) – Cu(II), Mn(II) – Pb(II), Co(II) – Cu(II), Mn(II) – Ni(II), and Mn(II) – Co(II) – Cu(II). The recovery of copper(II) is quantitative (98.0–99.0%) from test solutions (10–50 mg/L) by 1 mol/L HNO3-0.01 mol/L EDTA. The chelating resin is stable in acidic solutions below 2.5 M HNO3 or HCl as well as in alkaline solution below pH 11. The adsorption behavior of the resin towards Cu(II) was found to follow Langmuir isotherm and second order rate. 相似文献
964.
965.
966.
介绍了盾构机推进系统的工作原理,列出了盾构机推进允许的条件,并结合具体实例,分析了故障产生的原因,并对如何排除推进系统的故障进行了论述,以保证盾构机推进系统的正常运转。 相似文献
967.
Juan Tong 《Water research》2009,43(12):2969-2976
In previous publications we reported that by controlling the pH at 10.0 the accumulation of short-chain fatty acids (SCFA) during waste activated sludge (WAS) fermentation was remarkably improved [Yuan, H., Chen, Y., Zhang, H., Jiang, S., Zhou, Q., Gu, G., 2006. Improved bioproduction of short-chain fatty acids (SCFAs) from excess sludge under alkaline conditions. Environ. Sci. Technol. 40, 2025-2029], but significant ammonium nitrogen (NH4-N) and soluble ortho-phosphorus (SOP) were released [Chen, Y., Jiang, S., Yuan, H., Zhou, Q., Gu, G., 2007. Hydrolysis and acidification of waste activated sludge at different pHs. Water Res. 41, 683-689]. This paper investigated the simultaneous recovery of NH4-N and SOP from WAS alkaline fermentation liquid and the application of the fermentation liquid as an additional carbon source for municipal wastewater biological nitrogen and phosphorus removal. The central composite design (CCD) of the response surface methodology (RSM) was employed to optimize and model the simultaneous NH4-N and SOP recovery from WAS alkaline fermentation liquid. Under the optimum conditions, the predicted and experimental recovery efficiency was respectively 73.4 and 75.7% with NH4-N, and 82.0 and 83.2% with SOP, which suggested that the developed models described the experiments well. After NH4-N and SOP recovery, the alkaline fermentation liquid was added to municipal wastewater, and the influence of volume ratio of fermentation liquid to municipal wastewater (FL/MW) on biological nitrogen and phosphorus removal was investigated. The addition of fermentation liquid didn't significantly affect nitrification. Both SOP and total nitrogen (TN) removal were increased with fermentation liquid, but there was no significant increase at FL/MW greater than 1/35. Compared to the blank test, the removal efficiency of SOP and TN at FL/MW = 1/35 was improved from 44.0 to 92.9%, and 63.3 to 83.2%, respectively. The enhancement of phosphorus and nitrogen removal was mainly attributed to the increase of influent SCFA, or rather, the increase of intracellular polyhydroxyalkanoates (PHA) which served as the carbon and energy sources for denitrification and phosphorus uptake. The addition of alkaline fermentation liquid to municipal wastewater, however, increased the effluent COD, which was caused mainly by the increase of influent humic acid, not protein or carbohydrate. 相似文献
968.
969.
970.
通过分析各个新风量控制方法的特性,结合大型商场的能耗特点,提出以CO2浓度.焓差法来控制商场内新风量.这种方法在空调系统全年运行时,能够最大限度地节省能源和改善室内空气品质.同时,排风对新风具有很可观的预热或预冷作用,在商场建筑空调系统中应尽量加装热回收装置,以提高系统的能量利用率. 相似文献