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71.
72.
Composite alkaline polymer electrolytes and its application to nickel-metal hydride batteries 总被引:2,自引:0,他引:2
In order to enhance the ionic conductivity of polyethylene oxide (PEO)-KOH based alkaline polymer electrolytes, three types of nano-powders, i.e., TiO2, β-Al2O3 and SiO2 were added to PEO-KOH complex, respectively, and the corresponding composite alkaline polymer electrolytes were prepared. The experimental results showed that the prepared polymer electrolytes exhibited higher ionic conductivities at room temperature, typically 10−3 S cm−1 as measured by ac impedance method, and good electrochemical stability. The electrochemical stability window of ca. 1.6 V was determined by cyclic voltammetry with stainless steel blocking electrodes. The influence of the film composition such as KOH, H2O and nano-additives on ion conductivity was investigated and explained. The temperature dependence of conductivity was also determined. In addition, polyvinyl alcohol (PVA)-sodium carboxymethyl cellulose (CMC)-KOH alkaline polymer electrolytes were obtained using solvent casting method. The properties of the polymer electrolytes were characterized by ac impedance, cyclic voltammetry and differential thermal analysis methods. The ionic conductivity of the prepared PVA-CMC-KOH-H2O electrolytes can reach the order of 10−2 S cm−1. The effect of CMC addition on the alkaline polymer electrolytes was also explained. The experimental results demonstrated that the PVA-CMC-KOH-H2O polymer electrolyte could be used in Ni/MH battery. 相似文献
74.
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
75.
We studied the influence of initial pH on hydrogen (H2) production using permeate from scotta (a partially deproteinized cheese whey from ricotta production) as substrate (51 g L?1 lactose). Dark fermentation was carried out at 35 °C in laboratory batch reactors, in an unbuffered system. Hydrogen production and metabolite (volatile fatty acids, ethanol, and lactic acid) evolution during a 96-h period were monitored in reactors with initial pH varying in the range 4–10. In all reactors, H2 production started only when pH fell below 6. However, it was much higher (+31%) in the reactors with initial alkaline pH. We conclude that H2 production occurs only at acidic pH values, but initial alkaline pH values increase the overall H2 production in dark fermentation of lactose-rich substrates. 相似文献
76.
Myint Myint Khaing Nanjun Chen Chuan Long Yunxi Li Fanghui Wang 《Polymer-Plastics Technology and Engineering》2018,57(11):1121-1130
A series of cross-linking chitosan-modified quaternary ammonium poly(2,6-dimethyl-1,4-phenylene oxide)s membranes (CS-QAPPO) were prepared by the Menshutkin reaction. The mechanical property, dimensional stability, and alkaline stability of the CS-QAPPO membrane have been impressively improved by introducing CS into PPO backbone. Even the hydroxide conductivity of CS-QAPPO membranes is higher than that of the pristine QAPPO membrane. The 20% chitosan-modified QAPPO membrane shows the best performance, and the hydroxide conductivity is 32 mS cm?1 at 90°C. The alkaline stability measurements demonstrated excellent chemical stability of the CS-QAPPO membrane in 2?M NaOH solution at room temperature after 2,000?h. 相似文献
77.
Carbon-supported bimetallic PtmPb1 (m = 1, 2, 3) electrocatalysts with different Pt/Pb atomic ratios were synthesized by a polyol method. The X-ray diffraction results reveal that a PtPb alloy formed in the PtmPb1/C electrocatalysts. TEM images show that the PtPb nanoparticles distribute uniformly on the carbon support, and are about 4–5 nm in size. The PtmPb1/C bimetallic catalysts show superior activities toward methanol electrooxidation reaction (MOR) than the Pt/C in alkaline media. Both CO stripping measurements and density functional theory studies reveal that CO adsorption decreased significantly on the PtmPb1/C bimetallic catalysts compared with on pure Pt, which may offer an explanation for the enhanced MOR activity of the PtmPb1/C bimetallic catalysts. 相似文献
78.
碱/表面活性剂复合驱油体系与胜利孤东原油间协同效应的研究 总被引:3,自引:4,他引:3
考察了碱/非离子表面活性剂OP10+石油磺酸盐Cy体系与胜利孤东原油及萃取其酸性组分后的剩余油间的动态界面张力特性,发现复合驱油体系中的外加表面活性剂、碱与原油原位生成的表面活性物质之间存在明显的协同效应。这种协同效应对低离子强度下短时间内的界面张力影响较大;外加表面活性剂对高离子强度下长时间的界面张力影响较大。动态界面张力的最低值与界面上各表面活性物质的浓度和比值有着十分重要的关系 相似文献
79.
克拉玛依原油中活性组分的分离与分析 总被引:4,自引:0,他引:4
用碱醇液萃取法从克拉玛依原油中分离出了界面活性组分并进行了元素分析,通过硅胶柱层析按极性大小将该活性组分分成了5个级分,对5个级分进行了红外光谱分析,发现其主要成分是石油酸。用旋转滴法测定了该活性组分及其5个级分与碱水间的界面张力,结果表明的含氮化合物及石油酸具有较高的界面活性,可以使原油与NaOH水溶液的界面张力降至10^-2mN/m。 相似文献
80.
H184井组位于玉门老君庙油田L油藏顶部,由1口注入井和4口采油井构成反五点井网,井点圈定面积为9247m2,采出程度已达46%,含水高于99%。该井组L油层富含钙、镁离子并亲油,数量很少的残余油呈油膜覆于岩石颗粒表面,针对此特点,先导试验注入分3个阶段:碱性溶液预冲洗(为使L油层形成碱性环境,降低驱油剂的损失);注入胶束溶液;分4段注入聚丙烯酰胺溶液。该次先导试验总增产原油431t,采油动态反映驱油前缘推进均匀,体积波及系数较高;但驱油剂洗油效果不佳,原因是胶束溶液段塞未形成超低界面张力,加之表面活性剂油溶性太强,油未形成流动相;总投入产出比为10∶1,化学剂费用占总费用的66.7%,经济效益不佳。提高L油层采收率主要应提高驱油剂的洗油效率,需研制低价格、高效能的化学剂,因此老君庙油田不宜用先导试验所用胶束/聚合物驱油。图4参2(郭海莉摘) 相似文献