Separation of baicalin from Scutellaria Baicalensis Georgi with polyamide

Separation of baicalin from Scutellaria Baicalensis Georgi with polyamide was studied. The adsorption isotherm, kinetic equation and desorption law were investigated by static and dynamic adsorption methods. The results show that the kinetic behavior is mainly controlled by the liquid film diffusion process and obeys the Boyd film diffusion equation. Equilibrium data for the adsorption of baicalin are correlated with Freundlich isotherm equation, i.e. q=3.8Ce2.057, suggesting that the relative capacity of polyamide to baicalin is somewhat small. The desorption results indicate that the baicalin with mass fraction of 33.86% and the least impurities can be obtained by chromatography using 60% ethanol as the eluant at room temperature.     

Adsorption of K+ from an aqueous phase onto an activated carbon used as an electric double-layer capacitor electrode

The adsorption capacity and absorption rate for electrolyte onto activated carbon are important parameters used to characterize activated carbon electric double-layer capacitor electrodes. In this paper the pore structure of typical commercial activated carbons, and various Mn-doped activated carbons prepared on a laboratory scale, are described. The pore structure was characterized by N2 adsorption/desorption isotherms. Isotherms for K+ adsorption onto these activated carbons from the aqueous phase were also obtained. The experimental, equilibrium K+ adsorption data were fitted to the Langmuir, Freundlich or Temkin equations. Adsorption of K+ onto the activated carbons was measured and plotted as a function of time. The adsorption kinetic data were modeled by either pseudo-first or pseudo-second order equations. The Elvoich equation, a liquid film diffusion and an intra-particle diffusion model were used to fit the kinetic data. The results indicate that the adsorption of K+ onto activated carbon is influenced by many factors including pore size distribution, specific surface area and the surface chemistry of the activated carbons. The Temkin equation best describes the equilibrium adsorption data. The pseudo-second order model exactly describes the whole adsorption process, which is controlled by both liquid film and intra-particle diffusion.     

阴离子交换树脂分离提取发酵液中的乳酸

为提高乳酸产品收率和纯度,实验筛选得到国产315型阴离子交换树脂,用于分离提取发酵液中乳酸,并研究其对乳酸、乙酸、丙酮酸及柠檬酸的吸附等温线、吸附动力学和动态吸附及洗脱效果．吸附等温线结果表明,315型树脂对乳酸等有机酸的吸附等温线符合Freundlich方程,特征参数n>1,属于优惠吸附．吸附动力学研究表明,液膜扩散是吸附过程的主要控制步骤,符合Boyd 液膜扩散模型．动态吸附及洗脱实验结果表明,以15 BV／h、pH 188上柱吸附,再用1 BV／h的去离子水洗脱,可实现发酵液中乳酸的良好分离．     

Kinetics and mechanism of the adsorption of methylene blue onto ACFs

The kinetics and mechanism of methylene blue (MB) adsorption onto activated carbon fibers (ACFs) have been studied.The effects of various experimental parameters, such as the initial MB concentration and the ACF mass, on the adsorption rate were investigated. Equilibrium data were fit well by a Freundlich isotherm equation. Adsorption measurements show that the process is very fast. The adsorption data were modeled using first- and second-order kinetic equations and intra-particle diffusion models. It was found that the first-order kinetic equation could best describe the adsorption kinetics. The adsorption process was found to be complex and controlled by both surface and pore diffusion with surface diffusion at the earlier stages, followed by pore diffusion at the later stages. The thermodynamic parameters △G0, △S0 and △H0, have been calculated. The thermodynamics of the MB-ACF system indicate that the adsorption process is spontaneous.     

活性氧化铝对As (Ⅲ)和As (Ⅴ)的吸附性能研究

采用静态吸附试验方法,研究了活性氧化铝对As（Ⅲ）和As（Ⅴ）的吸附特性和机制.结果表明,活性氧化铝对As（Ⅲ）和As（Ⅴ）的吸附特性一致：室温条件下,吸附平衡时间约为24 h,动力学符合拟一级动力学模型,Boyd动力学模型说明液膜扩散是吸附反应速率的控制因素;与Freundlich等温线模型相比,Langmuir模型能够很好地描述吸附行为,说明以单分子层吸附为主;经过Dubinin-Radushkevich模型计算出的平均吸附自由能小于8 kJ·mol-1,表明吸附为物理过程;热力学参数表明吸附为自发、吸热、熵增加的过程,在吸附过程中,固-液界面的无序度增加.     

Methane adsorption behavior on coal having different pore structures

The adsorption of methane onto five dry coal samples was measured at 298 K over the pressure range from 0 to 3.5 MPa using a volumetric method. The isotherm data were fitted to the Langmuir and the Freundlich equations. The kinetic data were fitted to a pseudo second order equation, the linear driving force equation (LDF), and an intra-particle diffusion model. These results showed that higher methane adsorption is correlated with larger micro-pore volumes and specific surface areas. The adsorption was related to the narrow micro-pore size distribution when the previous two parameters are large. The kinetics study showed that the kinetics of methane adsorption onto these five dry coal samples followed a pseudo second order model very well. Methane adsorption rates are controlled by intra-particle diffusion. The faster the intra-particle diffusion, the faster the methane adsorption rate will be.     

新型螯合树脂聚苯乙烯负载葡糖胺对Pd(II)吸附性能的研究

合成了新型螯合树脂聚苯乙烯负载葡糖胺(PS-GA),并研究了所合成树脂对Pd(II)的吸附容量、吸附动力学、等温吸附等静态吸附性能及影响吸附的因素。结果表明:该树脂对Pd(II)的吸附量较高;树脂对Pd(II)的吸附为液膜扩散控制,吸附的活化能为59.76 kJ/mol;在实验浓度范围内,对Pd(II)的等温吸附符合弗伦德利希方程;较高温度有利于吸附;树脂可用2%的硫脲-0.1 mol/L HNO3清洗再生,再生后仍保持良好的吸附能力。     

聚偏氟乙烯多孔膜对水中刚果红的吸附性能

采用相转化法制备了聚偏氟乙烯（PVDF）多孔膜,并通过扫描电子显微镜、热重⁃差热分析仪对样品的表面及断面形貌、热稳定性进行了表征。研究了PVDF膜对水中刚果红的吸附性能。结果表明,PVDF膜的最佳投加质量为30 mg;在303 K下,PVDF膜的最大吸附量为64.6 mg/g;Freundlich等温模型更适合于描述刚果红的吸附行为,吸附动力学符合准二级动力学模型;热力学参数表明PVDF膜对刚果红的吸附是自发行为且为吸热反应;乙醇对吸附过刚果红的PVDF膜具有良好的脱附效果,经过8次吸附⁃脱附,PVDF膜对刚果红仍保持较高的吸附能力。     

离子交换树脂吸附稀硫酸中铁离子的热力学和动力学

采用静态实验法研究了D001树脂吸附铁离子的反应机理,在实验条件下分别用朗格缪尔(Langmiur)和弗伦德利希(Freundlich)等温吸附模型分析了D001树脂对铁离子的吸附热力学过程.结果显示:Langmuir方程有更高的相关性,能够更好地拟合树脂吸附铁离子的过程.热力学函数ΔG<0表明D001树脂吸附铁离子过程能够自发进行;ΔH>0表明离子交换过程为吸热过程,ΔS>0表明吸附过程的熵变是增大的.准二级动力学模型能够很好拟合D001树脂吸附铁离子的过程并且其相关系数在0.99以上,树脂对铁离子的吸附过程主要速率控制过程为颗粒扩散.     

Tungsten removal from molybdate solutions using chelating ion-exchange resin:Equilibrium adsorption isotherm and kinetics

The equilibrium adsorption isotherm and kinetic of the sorption process for W and Mo on macro chelating resin D403 were investigated on single Na2 Mo O4 and Na2WO4 solutions.The sorption isotherm results show that the adsorption process of W obeys the Freundlich model very well whereas the exchange process with Mo approximately follows the Henry model.The kinetic experiments show that the intraparticle diffusion process was the rate-determining step for W sorption on the resin,and the corresponding activation energy is calculated to be 21.976 k J/mol.     

程序控温吸附法对分子筛扩散性能的研究

提出了研究气体分子在沸石分子筛晶内孔中活化扩散的抛物线降温吸附法,经理论推导得到了计算晶内活化扩散动力学参数的基本公式,同时解决了降温过程中吸附动力学参数的计算问题。在前人工作的基础上,对研究多孔物质扩散性能的 TPD 公式加以改进,使其能够适于沸石分子筛的晶内活化扩散研究。对实际体系的研究结果表明:当采用抛物线降温吸附法对沸石分子筛进行研究时,可根据一次实验的数据,经一次回归计算得到气体分子在沸石分子筛晶内孔中的活化扩散动力学参数及吸附动力学参数,能够方便地进行活化扩散及吸附的研究,并可结合 TPD 数据进一步说明扩散和吸附所具有的特性。     

萘在松花江沉积物上的吸附解吸行为

为了探索萘在松花江沉积物上的吸附-解吸特性,采用实验室模拟方法进行研究.结果表明:萘在沉积物上的吸附在8 h内可以充分达到平衡,吸附过程表现出一定的非线性,与Linear和Langmuir方程相比,Freundlich方程能够较好地拟合萘的吸附和解吸过程,拟合度分别为0.93和0.962.萘的解吸行为存在较为明显的滞后现象,随水体中平衡浓度升高,萘的迟滞系数降低.     

Adsorption of Quaternized-chitosan-modified Reduced Graphene Oxide

A novel quaternized-chitosan-modified reduced graphene oxide(HACC-RGO) combined the adsorption advantages of RGO and 2-Hydroxypropyltrimethyl ammonium chloride chitosan(HACC). The adsorption property of HACC-RGO sheets for methyl orange(MO) was demonstrated and compared with RGO and HACC. The removal ratios of HACC-RGO sheets reached 92.6% for MO after a 24 h adsorption. The adsorption kinetics, isotherms and thermodynamics were investigated to indicate that the kinetics and equilibrium adsorptions were well-described by pseudo-second-order kinetic and Freundlich isotherm model, respectively. The thermodynamic parameters suggested that the adsorption process was spontaneous and endothermic in nature. Moreover, monodisperse HACC-RGO/CS beads were fabricated by the microfluidic method. The adsorption and desorption of HACC-RGO/CS beads for MO were studied. After three adsorptiondesorption cycles, the adsorption capacity remained above 55% and the desorption capacity was not below 70%. The HACC-RGO/CS beads can be reused and have great potential applications in removing organic dyes from polluted water.     

Experiment of gas diffusion and its diffusion mechanism in coal

In coal, the gas mainly exists in a free or an adsorption state. When the coal containing gas is damaged, gas desorption and diffusion will occur which can result in gas disaster. This research on gas desorption and diffusion provides a theoretical basis for gas disaster mechanism and prevention. The influence of pressure and temperature on gas diffusion is studied by the experiment. And the mechanism of pressure and temperature on gas diffusion is also analysed. The research results indicate that gas diffusion capacity increases with increasing temperature under the same pressure for the same coal sample. This is mainly because the temperature increases, gas molecular hot motion is severer, kinetic energy of gas molecular increases, and gas desorption quickens, therefore gas diffusion capacity changes stronger. Under other unchanged conditions, the greater gas adsorption balance pressure, the more gas adsorption content, and the higher the initial gas concentration. When gas diffusion begins, the greater the gas concentration gradient, the faster the gas diffusion speeds.     

2,4-二氯苯酚在松花江沉积物上的吸附解吸

在松花江3个典型断面(哈尔滨、达连河和佳木斯)采集了3类不同性质的沉积物,分别研究了2,4-二氯苯酚在松花江沉积物上的吸附-解吸特性.结果表明:2,4-二氯苯酚在3种沉积物上的吸附在24h内均可达到吸附平衡,其吸附-解吸过程符合Freundlich方程(R20.92).在3类沉积物样品上的吸附作用强度大小依次为佳木斯沉积物达连河沉积物哈尔滨沉积物.2,4-二氯苯酚在3种沉积物上吸附-解吸滞后系数(HI)都小于1,说明2,4-二氯苯酚的解吸行为存在较为明显的滞后现象,HI值大小依次为:哈尔滨达连河佳木斯.HI值与沉积物理化性质成正相关(R20.444).     

活性炭吸附水中罗丹明B的研究

采用批量吸附实验,研究了活性炭对水中罗丹明B的吸附行为,探讨了活性炭用量、吸附时间对水中罗丹明B吸附的影响,并对活性炭再生效果进行了测定.结果表明,利用活性炭处理罗丹明B,具有处理效果好、再生容易等特点.运用Langmuir等温吸附方程对其吸附进行了描述,表明吸附属于化学吸附;用准二级吸附动力学方程和准一级吸附动力学方程对实验数据进行了回归分析,准二级吸附动力学方程能更好地描述罗丹明B在活性炭上的吸附.     

羧基修饰的吸附树脂对1,2-苯并异噻唑-3-酮(BIT)的吸附研究

采用偏苯三甲酸酐、均苯四甲酸酐修饰氯甲基化的低交联大孔聚苯乙烯-二乙烯苯制备的超高交联吸附树脂(分别命名为ZT3和ZT4),通过比表面及孔径分析对其结构进行表征。以Amberlite XAD-4树脂作参照,通过等温吸附实验和吸附动力学实验探讨了修饰后的树脂对水溶液中BIT的吸附性能和机理。结果表明:ZT3、ZT4修饰的树脂比Amberlite XAD-4树脂对水溶液中BIT具有更好的吸附效果,这主要归因于树脂的微孔面积、高比表面积和树脂表面的羧基,Langmuir和Freundlich方程均能较好拟合修饰树脂对BIT的吸附等温线。BIT在ZT3和ZT4树脂上的吸附量都是随着溶液pH的增大而减小。     

金属有机骨架材料ZIF⁃67对甲基橙的吸附性能

采用溶剂热法合成了金属有机骨架材料ZIF?67,并通过扫描电子显微镜（SEM）、X?射线粉末衍射（XRD）、傅里叶红外光谱（FT?IR）以及热重（TG）对其进行表征。将合成的ZIF?67用于水中甲基橙的吸附,系统地研究了pH、吸附剂质量、甲基橙初始质量浓度、接触时间和温度对吸附性能的影响。结果表明,当ZIF?67质量为20 mg、pH为7时,吸附效果最好;在303 K下吸附25 min达到平衡;在303 K下,ZIF?67对甲基橙的理论最大吸附量为152.67 mg/g。等温吸附数据符合Langmuir等温吸附模型,吸附动力学符合准二级吸附动力学模型,该吸附过程是一个自发的放热过程。乙醇可以对吸附后的ZIF?67较好地脱附,经过6次吸附?脱附循环仍保持较好的吸附效果。     

煤层气流动物质平衡方程的建立及应用分析

介绍了煤层气的吸附解吸特性,以及考虑吸附解吸特性的单相煤层气的扩散方程,并在该扩散方程拟稳态解的基础上,详细推导了单相煤层气的流动物质平衡方程,所得到的煤层气流动物质平衡方程可以有效确定单相煤层气储层的地质储量,同时也可以用来计算煤储层的渗透率。     

Adsorption of BSA on Carbon-coated Fe_3O_4 Microspheres Activated with 1-ethyl-3-(3-dimethylaminopropyl)-Carbodiimide Hydrochloride

Carbon-coated Fe_3O_4( Fe_3O_4/C) microspheres activated with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride(EDC) were prepared, characterized and applied to adsorb bovine serum albumin(BSA). The prepared magnetic microspheres had spherical core-shell structure with a uniform and continuous carbon coating coupled with activation by EDC, and possessed superparamagnetic characteristics. The experimental results showed that the adsorption amount of BSA on the EDC-activated Fe_3O_4/C(Fe_3O_4/C-EDC) microspheres was higher than that on the Fe_3O_4/C microspheres. The maximum adsorption of BSA on Fe_3O_4/C-EDC microspheres occurred at pH 4.7, which was the isoelectric point of BSA. At low concentrations(below 1.0 M), salt had no noticeable effect on BSA adsorption. The BSA adsorption of Fe_3O_4/C-EDC microspheres had a better fit to the Langmuir model than the Freundlich isotherm and Temkin isotherm model, and the kinetic data were well described by the pseudo-second-order model. The adsorption equilibrium could be reached within 20 min. High desorption efficiency(97.6%) of BSA from Fe_3O_4/C-EDC microspheres was obtained with 0.5 M Na_2HPO_4(pH 9.4) as the desorbent.