活性炭吸附CO2与其微孔体积的关系

对五种活性炭样品进行液氮温度下的N2吸附、碘吸附测定和冰点下的CO2吸附表征。结果表明,碘吸附值测定法和基于N2吸附等温线的BET方程、D-R方程,孔结构参数都不能正确反映活性炭对CO2的吸附特性;由CO2吸附等温线得到的D A模型参数也不适合分析活性炭吸附CO2特性;CO2吸附等温线的密度泛函理论（DFT）分析结果表明,CO2在活性炭上的吸附发生在极微孔内,DFT分析的微孔孔容与吸附等温线反映的吸附性能完全一致。因此,根据CO2吸附等温线的DFT模型是准确反映活性炭吸附CO2特性的表征分析方法。     

Thermodynamics and Kinetics of Bacterial Cellulose Adsorbing Persistent Pollutant from Aqueous Solutions

The adsorption capability of bacterial cellulose(BC) for anionic dye acid fuchsine was studied. Meanwhile, the processes of the adsorption were investignted and fitted by adsorption isotherm models, adsorption thermodynamics and adsorption kinetics models, respectively. The changes of BC before and after adsorbing acid fuchsine were investigated via scanning electron microscopy(SEM) and Fourier transform infrared spectroscopy(FTIR) to further explain the adsorption mechanism. The results show that acid fuchsine could be effectively adsorbed by BC. The adsorption process was fitted well by Langmuir equation and the pseudo-second order kinetics, indicating that the adsorption process was monolayer molecule adsorption with the main action of chemical adsorption. The adsorption process was spontaneous and endothermic. Glucuronic acid groups and hydroxyl groups were responsible for the adsorption of acid fuchsine on BC.     

Preparation of magnetic modified chitosan and adsorption of Zn²⁺ from aqueous solutions

The performance of a cross-linked magnetic modified chitosan (CMMC), which has been coated with magnetic fluids and cross-linked with glutaraldehyde, has been investigated for the adsorption of Zn(2+) from aqueous solutions. The CMMC with a diameter range of 20-50 nm was prepared. The effects of pH and the contact time for the adsorption have been discussed, and the optimal adsorption conditions for the adsorption of Zn(2+) have been obtained. The research results showed that CMMC was highly efficient for fast adsorption of Zn(2+) within the first 25 min, and adsorption equilibrium could be achieved in 30 min. Equilibrium studies showed that the data of Zn(2+) adsorption followed the Langmuir model. The maximum adsorption capacity for Zn(2+) was estimated to be 32.16 mg/g with a Langmuir adsorption equilibrium constant of 0.01 L/mg at 298 K, which demonstrated that the CMMC had obvious efficient adsorption of Zn(2+). The CMMC was stable and easily recovered. Moreover, the adsorption rate was about 90% of the initial saturation adsorption capacity after being used five times.     

不同吸附模式对As(V)在TiO2颗粒上亚稳态吸附的影响

通过对比As(V)在TiO₂颗粒上的柱(column)吸附和静态(batch)吸附行为, 研究了柱吸附和静态吸附两种反应模式对该体系亚稳态吸附的影响. 在相同热力学条件下, 将总量一定的As(V)溶液分别加入柱吸附和静态吸附体系中. 结果表明, 随着吸附模式的改变, 静态吸附体系比柱吸附体系更快达到吸附平衡, 静态吸附体系平衡吸附量(0.42 mg·g^-1)明显高于柱吸附体系平衡吸附量(0.25 mg·g^-1), 且静态吸附体系的吸附不可逆性弱于柱吸附体系的吸附不可逆性. 说明溶质吸附模式(动力学条件)的改变使得相同热力学条件下的吸附反应达到了不同的平衡状态. 柱吸附和静态吸附实验中, As(V)在TiO₂颗粒上的液膜扩散系数、总传质系数及吸附平衡后形成的微观吸附状态均不同, 共同导致了两种反应宏观吸附行为上的差异.     

聚环糊精的制备及其对苯酚的吸附性能研究

合成了β-环糊精聚合物，并采用红外光谱、元素分析及BET吸附法对聚环糊精进行了表征．从吸附动力学和热力学角度研究了聚环糊精对苯酚的吸附性能，拟合出了Langmuir吸附模型中的各参数．结果表明，聚环糊精对苯酚的吸附容量可达12mg／g以上，且吸附能力主要来自聚环糊精对苯酚的包合作用．     

超临界甲烷在活性炭上的吸附平衡分析

为分析由吸附平衡时的热力参数确定吸附量、吸附模型和等量吸附热精度的影响因素,选择在温度268.15~338.15 K和压力0~13.5 MPa测试的甲烷在Ajax活性炭上的吸附平衡数据,通过引入甲烷分子可进入活性炭吸附空间内的容积和可以不考虑甲烷在孔内吸附的临界孔宽的概念,依据甲烷在吸附平衡前后的总量守恒,确定甲烷在吸附池内的总量、绝对吸附量和过剩吸附量三者之间的关系式。结果表明,在引入吸附质分子可进入吸附空间内的容积和临界孔宽后,经由活性炭的孔径分布(PSD),可以准确计算甲烷在活性炭上的过剩吸附量;应用实验数据非线性回归Toth方程参数后,可由Gibbs关于吸附的定义确定甲烷在活性炭上的绝对吸附量。比较结果时发现,由于未考虑本体相中甲烷分子对吸附甲烷分子的影响,采用过剩吸附量的等量吸附线标绘确定的等量吸附热数值偏高,工程应用时应由绝对吸附量来确定等量吸附热。     

Kinetics of adsorption and desorption of Pb(II) in aqueous solution on activated carbon by two-site adsorption model

The adsorption and desorption equilibrium and kinetics of lead ions from aqueous solutions on a granular activated carbon (GAC) were examined. Rapid increase followed by slow increase in Pb(II) amount on the GAC was observed as a function of time for the adsorption, while rapid decrease and consecutive very slow decrease was observed in desorption. Based on the experimental results, a two-site adsorption model was proposed for the adsorption and the desorption of Pb(II) under the study conditions. The Pb(II) adsorption on the GAC was estimated to have simultaneously occurred on the strong and the weak adsorption sites. Conventional Langmuir-type kinetic equations were introduced to quantitatively predict the adsorption and desorption with the two-site model by optimizing the parameters to fit the equilibrium and the kinetic experimental results. The equilibrium and kinetic experimental results could be represented by the equations by using one set of the common Langmuir parameters. Resultant kinetic parameters revealed that the adsorption equilibrium constant was two orders of magnitude greater for strong adsorption site than for weak adsorption site, though the maximum number of weak adsorption site was 1.5 times as great as that of strong adsorption site. The strong adsorption equilibrium constant resulted from a small desorption rate constant for the site. The equations were demonstrated to be applicable for predicting other desorption performances as well.     

Sulfate adsorption and surface precipitation on a volcanic ash soil (allophanic andisol)

Sulfate strongly adsorbs on metal oxides and soils with variable charges. However, its surface precipitation has not been clearly evaluated and its adsorption mechanism has been in dispute. In the present study, an allophanic andisol, a typical volcanic ash soil having both negative and positive variable charges, was used to identify the adsorption mechanism of sulfate. Sulfate adsorption isotherms were obtained by a batch method at pH values of 4, 5, 6, and 7 in a wide range of concentrations in an Na-H-SO(4)-OH system. Theoretical isotherms were applied to the measured values for the evaluation. The surface precipitation was detected by the measured adsorption isotherms, and the BET isotherm confirmed the presence of multilayer adsorption. Stronger and weaker adsorption sites were suggested by using the Langmuir isotherm for the monolayer adsorption. The adsorption energies obtained from the Langmuir equation and recent spectroscopic analysis suggested that the stronger adsorption corresponded to an inner-sphere surface complex and that the weaker adsorption corresponded to outer-sphere surface complexation. The BET and Langmuir equations showed three types of adsorption mechanisms for the sulfate adsorption on the soil.     

硅胶自水溶液中吸附丙酸和丁酸的计量置换吸附模型

实验研究了硅胶在293、303和313 K下,从水溶液中对丙酸和丁酸的吸附.发现该吸附服从液 固吸附中的计量置换吸附模型（SDM A）.根据吸附模型的线性参数研究了吸附热力学和吸附机理.该吸附是一个自发的、放热的熵减少过程.丁酸的标准吸附自由能比丙酸大,而标准吸附焓比丙酸小.推导出了实验条件下吸附自由能变化的计算公式.     

用大孔吸附树脂分离利血平

以利血平的吸附量和解吸率为指标,筛选大孔吸附树脂.研究吸附和解吸的优化条件,并考察选定树脂的吸附等温线、吸附动力学、吸附和解吸性能.结果表明,将催吐萝芙木根粉浸提液蒸去乙醇且不调pH(pH 1)进行吸附,HZ-818型大孔吸附树脂对利血平的吸附量可达到9.34mg/mL.使用工业乙醇-水(80:20,pH 1.0)为解吸剂,解吸率可达99.3%.该树脂的吸附符合Langmuir吸附等温方程.吸附前期,吸附速度较快,以后速度减慢.HZ-818型树脂对利血平的吸附量大,解吸率高,通过大孔树脂吸附和解吸,利血平浓度提高50倍以上,适宜于工业化生产.     

苦味酸在聚酰胺树脂上的吸附热力学及动力学

在静态下,考察了温度对聚酰胺树脂吸附水溶液中苦味酸的影响,探讨了吸附的热力学、动力学规律.结果表明:温度对吸附的影响较小,等温吸附规律可用Freundlich或Langmuir方程表示;吸附过程为熵驱动的吸热、熵增的自发过程;属物理吸附范畴;吸附动力学规律可用q=aeb/t吸附速率方程表示,属颗粒内扩散控制.     

聚（对乙烯基苄基己内酰胺）树脂对非水体系中苯酚的吸附热力学

测定了聚（对乙烯基苄基己内酰胺）吸附树脂对正庚烷溶液中苯酚的吸附等温线,发现吸附等温线符合Freundlich等温吸附方程,相关系数大于0．99．根据热力学函数关系计算了等量吸附焓、Gibbs吸附自由能和吸附熵,等量吸附焓在30～40kJ／mol之间,推测吸附过程为氢键吸附．通过比较树脂对正庚烷中苯酚和邻硝基苯酚的吸附性能的差别,进一步论证了树脂对非水体系中酚类物质的吸附是基于氢键作用的机理．同时,聚（对乙烯基苄基己内酰胺）树脂对正庚烷溶液中苯酚的吸附相对水溶液中苯酚的吸附有更低的吸附焓变、吸附自由能变和吸附熵变．     

介孔碳CMK-3对苯酚的吸附动力学和热力学研究

研究了介孔碳CMK-3对苯酚的吸附性能, 与传统商用活性碳(CAC)进行了比较, 结果表明, CMK-3比CAC的吸附量大、吸附速率快、达到平衡时间短, 是一种较好的吸附剂. 同时探讨了介孔碳CMK-3对苯酚的吸附热力学和动力学特征. CMK-3对苯酚的吸附行为可用Langmuir和Freundlich等温式进行描述, 相关性都较好, 但更符合Freundlich经验公式. 分别采用模拟一阶反应和二阶反应模型考察了吸附动力学, 并计算了这些动力学模型的速率常数. 模拟二级反应模型和实验数据之间有较好的相关性. 分别计算了热力学参数ΔG0, ΔS0和ΔH0, 结果表明, CMK-3对苯酚的吸附过程是吸热和自发的.     

柱芳烃基多孔聚合物的制备及其吸附性能

将柱[5]芳烃与1,3,5-三乙炔苯(TEB)通过Sonogashira偶联反应制备了一类新型多孔有机聚合物P[5]-TEB,进而通过脱甲基反应对其进行改性得到多羟基的多孔聚合物P[5]OH-TEB,对二者的物理化学性质和吸附性能进行研究。 氮吸附测试表明,羟基的引入使P[5]OH-TEB的比表面积变大,同时引入微孔结构。 染料吸附实验表明,两聚合物对亚甲基蓝吸附过程符合Langmuir模型,P[5]OH-TEB对亚甲基蓝有更大的吸附量;吸附动力学试验表明,吸附过程更符合拟二级动力学模型,属于化学吸附过程,改性之后P[5]OH-TEB有更快的吸附速率;选择性吸附实验表明,羟基引入聚合物后聚合物对阳离子染料的吸附性能提升,对阴离子染料的吸附效果变差。     

焦木素对苯酚吸附性能的研究

随着环境科学的不断发展 ,水中越来越多的有机化合物被检测出来 ,它们的存在对人体的危害已日益引起人们的关注。酚类化合物是环境中的一类主要污染物 ,来源于炼油、炼焦、煤气洗涤、造纸、化工等工业废水和废弃物 ,酚类影响水中生物的正常生长 ,使水产品着臭。当水中酚含量在0 .3ｍｇ·ｍｌ- 1 以上时 ,可引起生物的逃逸。国内外学者利用各种吸附剂去除水中的酚[1～ 3] ,其中活性炭纤维去除效果最佳 ,但其价格昂贵 ,目前在我国难以广泛使用。本文所用焦木素是以造纸黑液提取的木素为原料制备的 ,其吸附性能与活性炭类似 ,其原料来源丰富 ,…     

Adsorption volume and absolute adsorption: 2. Adsorption from liquid phase

A critical analysis of the isotherms of excess and absolute adsorption, as well as the adsorption space performed in the first part [1] is continued; however, as applied to the equilibrium physical adsorption from the liquid phase. The correct method is proposed for evaluating the adsorption volume of solid adsorbents with an arbitrary structure by the isotherm of excess adsorption of binary mixture of liquids. This method is successfully tested for nine different adsorption systems.     

聚酯基硫脲树脂PDTU—I对Ag（I）的吸附性能研究

测定了聚酯基硫脲树脂对银离子的吸附容量,讨论了吸附时间、溶液酸度,温度及银离子初始浓度等因素对其吸附性能的影响,并对吸附动力学和热力学进行了研究。结果表明,树脂对Ag(I)的吸附遵循G.E.Boyd液膜扩散方程和Langmuir等温式,且吸附为吸热过程。     

Adsorption of Basic Yellow 28 from aqueous solutions with clinoptilolite and amberlite

The objective of this study was to investigate the adsorption of Basic Yellow 28 that is a cationic dye on clinoptilolite and amberlite XAD-4. Both equilibrium and batch rate adsorption in aqueous solutions of the dyestuff were investigated. Adsorption rate data were analysed using the pseudo-first order kinetic model of Lagergren and the pseudo-second order model to determine adsorption rate constants at 20, 30 and 40 degrees C. The adsorption equilibrium data were analysed using various adsorption isotherm models and the results have shown that adsorption behaviour of Basic Yellow 28 by clinoptilolite and amberlite could be described by either Langmuir or Freundlich models. Langmuir adsorption isotherm constants corresponding to adsorption capacity, Q(0), were found to be 59.6, 52.9 and 56.7 mg/g for clinoptilolite at 20, 30 and 40 degrees C, respectively. Lower adsorption capacities for Basic Yellow 28 on amberlite were obtained. The increase of adsorption rate constants with an increase in temperature for BY 28 adsorption on amberlite indicated chemisorption with dissociation and increased availability of sites due to higher penetration of adsorbing molecules into the pores.     

Dynamic measurements of adsorption of hydrolyzed polyacrylamide (HPAM) onto hematite

The adsorption measurements of hydrolyzed polyacrylamide (HPAM) onto hematite suspension are carried out to study the dynamics of the polymer adsorption onto the suspension particles and to investigate the mode of the polymer adsorption. The polymer is found to show much affinity for the adsorption because of the opposite charges possessed by the polymeric flocculant and the suspension particles. Various adsorption parameters such as adsorption coefficient, the rate constants for the adsorption and desorption, are evaluated with the help of a recently proposed kinetic scheme. It is found that the extent of adsorption and the adsorption rate are adequately affected by increasing the pH of the suspension while, unexpectedly, the adsorption is found to show only a marginal increase on addition of Na₂SO₄. Both the amount of the adsorbed polymer and the adsorption rate are also found to increase with the degree of hydrolysis of the polyelectrolyte.     

磁性共价有机框架材料吸附甲基橙和茜素绿两种阴离子有机染料

以自制的磁性共价有机框架材料(COF)为吸附剂,采用静态吸附法研究了其对甲基橙(MO)和茜素绿(AG-25)的吸附行为。 结果表明,在25 ℃,pH值6~8的条件下,磁性COF对两种阴离子染料的的吸附量分别为997和1314 mg/g。 两种染料的吸附等温线符合Langmuir等温吸附模型,表明吸附过程为单层吸附;吸附动力学均符合准二级动力学模型,说明吸附过程以化学吸附为主。 磁性COF对水体中的阴离子染料体现出高吸附量和快速吸附的特点,具有潜在的价值。