共查询到19条相似文献,搜索用时 62 毫秒
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吸附热预测吸附等温线 总被引:1,自引:0,他引:1
实验测定了N2 在沸石分子筛、C2 H6 在活性炭、CO2 在硅胶上的吸附等温线 ,研究用Clausius Clapeyron方程求得等量吸附热、再利用所得的吸附热预测其它温度的吸附等温线数据的方法。将吸附热预测的等温线与实验值及插值法内插得到的吸附等温线数据进行了比较 ,结果表明吸附热预测值与实验值吻合较好。此外还对文献数据利用等量吸附热预测较高压力 ( 65 0kPa)下的等温线 ,均与文献中的实验值一致。为吸附工业操作需要不同温度下的等温线数据和吸附过程的模拟与设计提供了简便、准确的计算方法 相似文献
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膨润土对Pb~(2+)的吸附及铝的影响研究 总被引:1,自引:0,他引:1
研究膨润土对水溶液中铅的吸附特性以及铝对铅吸附的影响。通过各组吸附实验,建立膨润土对水溶液中铅离子的吸附最佳条件,天然膨润土对铅的吸附平衡时间约为60 min,其吸附符合一级动力学方程;铅吸附最适p H=9;天然膨润土对水溶液中铅离子的吸附规律符合Freundlich等温方程和Langmuir等温方程,呈显著相关性;加入少量铝离子时,吸附除铅能力增强,但继续增加铝浓度,去除能力降低,该现象主要通过铝盐水解所致的p H变化起调节作用,电中和作用不明显。 相似文献
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绘制脱色吸附等温线的便捷方法使用活性炭脱色在化工生产中具有重要的实际意义。而绘制脱色吸附等温线是研究吸附的行之有效的基本方法,实验上通常采用可见分光光度法。由于制备活性炭的材质、生产工艺及保管等原因,活性炭的吸附性能差异性极大;当运用比色法测定吸附平... 相似文献
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在超声作用下,以十四烷基三甲基溴化铵对膨润土进行改性,制备了纳米有机膨润土。通过红外光谱(FTIR)、X-射线衍射(XRD)对纳米有机膨润土进行表征。结果表明有机改性剂进入膨润土层间,层间距由L38nm增大为2.10nm。实验测试了该材料对品绿的吸附性能,结果显示在25℃,对品绿的最大理论吸附量为333.97mg/g,高于原土的最大理论吸附量243.21mg/g。用不同模型对吸附等温线及动力学数据进行了拟合,结果表明准二级动力学方程所得参数更为合理,更符合实验数据,等温吸附平衡更符合Langmuir模型。 相似文献
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A mathematical method was proposed for the determination of absolute adsorption from experimental isotherms. The method is based on the numerical equality of the absolute and the excess adsorption when either the gas phase density or the amount adsorbed is not quite considerable. The initial part of the experimentalisotherms, which represents the absolute adsorption, became linear with some mathematical manipulations. The linear isotherms were reliably formulated. As consequence, either the volume or the density of the supercritical adsorbate could be determined by a non-empirical way. This method was illustrated by the adsorption data of supercritical hydrogen and methane on a superactivated carbon in large ranges of temperature and pressure. 相似文献
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针对由吸附等温线模型回归气体吸附平衡数据的准确性进行了研究,从实验误差和表面覆盖率两个因素出发,主要考查了它们对回归Langmuir、DR方程两种等温线模型中各参数的影响,并对回归参数的可靠性作了分析。实验误差和表面覆盖率对各模型参数回归的准确性均有影响。对于Langmuir和DR方程,提高测试的表面覆盖率可以更可靠地计算出饱和吸附量以及模型中的其它参数。另外,仅通过减小实验误差来保证模型中所有参数的准确性是不可取的。 相似文献
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《分离科学与技术》2012,47(9):1286-1294
The adsorption of cephalexin in aqueous solution has been investigated using bentonite and activated carbon as the adsorbents. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, adsorbent dosage, pH, particle size, and temperature. Adsorption equilibrium data were well represented by the Langmuir and Freundlich isotherm models. The adsorption intensity was found to be increased as the aqueous phase pH increased, and had a maximum at pH = 6.1. The pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models were used to describe the kinetic data. The experimental data fitted very well with the pseudo-second-order kinetic model and also followed the simple external and intraparticle model. 相似文献
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This study investigated a number of models (the modified Sips', Dubinin‐Astakhov's, VSM theory, the generalized Khan et al.'s model and a simple artificial neural network (ANN)) to predict the effect of temperature on equilibrium adsorption of hydrocarbon gases and vapors on activated carbon. Published data on the adsorption of methane, ethane and propane on activated carbon at 311 K to 505 K were used to estimate the parameters of the conventional models and train the network. Then, the conventional models and the ANN were used to predict the isotherm at a single temperature for each adsorbate, and these results were compared with experimental data. It was found that the ANN model had a lower mean relative error than the conventional models. 相似文献
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有机膨润土吸附废水中苯酚的机理 总被引:2,自引:0,他引:2
以C12阳离子烷基多糖苷季铵盐对膨润土改性制备有机膨润土,探讨了有机膨润土的制备因素对去除废水中苯酚效果的影响,结果表明,在有机改性剂/膨润土的质量比为40 mg/g,反应温度为30℃,pH=8的条件下,反应30 min制备的有机膨润土,对初始浓度为50 mg/L的含苯酚废水去除率达到89.50%,其对苯酚的吸附符合Freundish方程。 相似文献
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通过接枝反应制备了一系列以聚环氧氯丙烷为主链,侧链末端含吡咯配位基的HPnCP(n=6,4,2)螯合树脂,各步产物的化学结构经IR和1H NMR检测得以确认。静态吸附实验及等温吸附实验结果表明:该类树脂对Cu(Ⅱ)和Hg(Ⅱ)有着较好的吸附性能(大于1.0mmol/g);对Co(Ⅱ)和Cd(Ⅱ)达到饱和吸附时的平衡浓度约为0.06~0.07mol/l;HP_4CP对Co(Ⅱ)和Cd(Ⅱ)以及HP_2CP对Co(Ⅱ)的等温吸附既可用Langmuir方程描述也可用Freundlich方程描述;但HP_2CP对Cd(Ⅱ)的等温吸附不符合Langmuir方程,只可用Freundlich方程描述。 相似文献
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Adsorption isotherm is the most fundamental information related to chromatography.To calculate the parameters of Langmuir adsorption isotherm of thymidine,fronal analysis(FA)and lution-curve method(ECM)were adopted in reversed-phase high performance liguid chromatography(RP-HPLC).In FA,tha concentration of stationary phase was measured from the elution curves and the isotherm was determined by regression analysis,while the parameters by ECM were obtained by parameter optimization.The adsorption isotherms of thymidine from the two methods were very similar.The superiority of ECM over FA was that the consumption of sample was less and only one or two in jections of sample were required. 相似文献