硫酸体系中P507浸渍树脂吸附Cd(Ⅱ)的研究

选用2-乙基已基膦酸单(2-乙基已基)酯(P507)为萃取剂,HZ818大孔树脂为载体,以干法浸渍技术制备了P507浸渍树脂.研究了吸附平衡时间、溶液pH和树脂用量对硫酸体系中该浸渍树脂吸附Cd(Ⅱ)的影响.静态吸附实验表明,吸附过程符合准二级动力学模型.采用0.5mol/L的盐酸溶液可将吸附在树脂上的Cd(Ⅱ)洗脱下来.     

表面活性剂改性P507浸渍树脂吸附In（Ⅲ）的性能研究

首先以阳离子表面活性剂CTAB(十六烷基三甲基溴化铵)对AB-8大孔树脂进行表面改性,然后浸渍到含萃取剂P507[2-乙基己基磷酸单(2-乙基己基)酯]的石油醚溶液中,制备了P507浸渍树脂,研究了该改性树脂吸附In(Ⅲ)的热力学和动力学性能,并进行了动态吸附和脱附实验。结果表明,用CTAB对AB-8大孔树脂进行表面改性后,P507在树脂上的负载量和In(Ⅲ)在树脂上的吸附量都显著提高,其中P507的负载量提高了32.2%,In(Ⅲ)的吸附量提高了21.2%。In(Ⅲ)在改性P507浸渍树脂上的等温吸附符合Langmuir吸附方程,饱和吸附量为32.5mg/g;对In(Ⅲ)的吸附为吸热过程,升高温度有利于In(Ⅲ)的吸附,ΔH=5.28kJ/mol,ΔG(303K)=-2.18kJ/mol,ΔS=24.61J/mol.K。在pH=1.0时In(Ⅲ)在P507浸渍树脂上的吸附效果最好,而且易于与Al(Ⅲ)、Zn(Ⅱ)等杂质离子进行分离。     

表面活性剂对AB-8大孔树脂负载萃取剂的影响及Ga(Ⅲ)和Al(Ⅲ)的吸附分离研究

AB-8型大孔树脂是弱极性苯乙烯共聚体,可制成负载萃取剂的浸渍树脂,用于贵金属的提取和分离。萃取剂负载量的大小对树脂的吸附分离性能有很大影响。为提高AB-8型大孔树脂对萃取剂的负载量,本文首先采用阴离子型表面活性剂SDS(十二烷基硫酸钠)、非离子型表面活性剂TX-10[辛基酚聚氧乙烯(10)醚]以及阳离子表面活性剂CTAB(十六烷基三甲基溴化铵)分别对AB-8大孔树脂进行表面改性,然后以浸渍方法制备分别负载萃取剂TBP(磷酸三丁酯)、P_(507)[2-乙基己基磷酸单(2-乙基己基)酯]、TOA(三辛胺)的浸渍树脂,考察了表面活性剂对萃取剂负载量的影响。通过动态吸附和脱附实验,研究了改性P507浸渍树脂对Ga~(3+)与Al~(3+)的分离性能。结果表明,SDS对TBP的负载量基本无影响,TX-10和CTAB均使TBP的负载量明显减小。SDS、TX-10、CTAB均可提高P507和TOA的负载量,其中,CTAB使P_(507)的负载量提高最多。改性P_(507)浸渍树脂对Ga~(3+)的平衡吸附量为26.3mg/g,比未改性时的平衡吸附量提高了5.47mg/g。CTAB改性的P507浸渍树脂可以使Ga~(3+)与Al~(3+)得到有效分离。     

6-氨基青霉烷酸在弱碱性阴离子树脂IRA67上的吸附研究

用静态法研究了6-氨基青霉烷酸在弱碱性阴离子交换树脂IRA67上的吸附行为．在溶液pH为8．0，6-APA起始浓度介子3.00mg／m1-20．00mg／ml条件下，测定了25℃时IRA67树脂的静态交换动力学曲线、吸附等温线，并求得了IRA67树脂的平衡速率常数及吸附等温线方程．分别用Langmuir型和Frendlich型方程对IRA67树脂吸附等温线进行线性回归拟合，结果表明，6-APA在IRA67树脂上的吸附更符合Langmuir型吸附．     

P-507回流萃取法富集镥的研究——Ⅰ.P-507萃取分离镱镥混合稀土的性能

本文研究了2-乙基己基膦酸单2-乙基己基酯(P-507)在盐酸和硝酸体系中萃取镱镥混合稀土的性能。说明P-507在硝酸体系中的萃取分离系数较其在盐酸体系中高,而在盐酸体系中有更高的反萃效率。与二(2-乙基己基)磷酸(P-204)相比,P-507具有萃取酸度低、易反萃和不易乳化的优点。我们还确定了回流萃取法分离镥镱的基本参数,表明P-507是一种新型的分离重稀土的良好萃取剂。     

阴离子交换树脂骨架结构对吸附单宁酸与五倍子酸的影响

选用聚丙烯酸系D730、FPA98和聚(苯乙烯-二乙烯苯)系的D201强碱型阴离子交换树脂作为吸附剂,系统研究单宁酸、五倍子酸在上述3种阴离子交换树脂上的吸附行为与机理。吸附等温线表明,聚丙烯酸系阴离子交换树脂对单宁酸的吸附性能优于聚苯乙烯-二乙烯苯系阴离子交换树脂,而聚(苯乙烯-二乙烯苯)系阴离子交换树脂对五倍子酸有较高的吸附容量。虽然3种阴离子交换树脂对单宁酸的吸附均为熵推动的自发吸附过程,静电引力是主要吸附作用力,但是在吸附过程中除离子交换作用外,D730和FPA98骨架上的羰基与单宁酸有较强的氢键作用,而D201骨架上的苯环与五倍子酸也存在着"π-π"共轭作用,从而提升离子交换树脂对鞣酸类物质的吸附性能。因此,影响离子交换树脂吸附性能的不仅是交换容量,其骨架结构对吸附性能也有较大影响。另外,上述吸附作用也会影响树脂吸附饱和后的脱附性能,相比较聚(苯乙烯-二乙烯苯)系强碱型阴离子交换树脂,聚丙烯酸系强碱型阴离子交换树脂有更好脱附性能。     

D301R树脂对Keggin型铁取代杂多阴离子的吸附性能研究

详细研究了D301R弱碱性阴离子交换树脂对Keggin型铁取代杂多阴离子PW11O39Fe(III)(H2O)4－ (PW11Fe)的吸附作用, 考察了不同pH和温度对吸附量和吸附速率的影响, 测定了不同温度下吸附的动力学曲线和吸附等温线, 提出吸附动力学模型和计算了吸附的热力学函数, 结果表明, 在pH 2～8的范围内, PW11Fe的吸附量随溶液pH值的升高而增加, 随溶液温度的升高而降低; 吸附动力学符合表面过程控制的准二级反应模型, 其速率常数k2在298 K时为 9.33×10－4 g•mg－1•min－1, 并随温度的升高而减小. 吸附等温线符合Freundlich吸附模型, 吸附热约为40 kJ•mol－1, 因此, 吸附为物理吸附.     

二-(2-乙基己基)磷酸-煤油液膜萃取锌(Ⅱ)的动力学分析

锌离子;二乙基己基磷酸;迁移动力学;二-(2-乙基己基)磷酸-煤油液膜萃取锌(Ⅱ)的动力学分析     

二(1-甲基庚基)磷酸萃取色层法分离稀土元素的研究

在萃取色层法分离稀土元素中,常用的固定相有:二(2-乙基已基)磷酸(P-204)、2-乙基已基苯基磷酸、2-乙基己基磷酸单2-乙基己基酯(P-507)等。二(1-甲基庚基)磷酸(P215)是P204的异构体,它的支链在α位置上,空间位阻较大,因此对稀土元素的分离应具有较高的分离因数,反萃取的酸度也应比P204的低。我们将P215用于萃取色层法以分离稀土。在一定的酸度下,可将14个稀土元素分离,在有硫酸铵存在时,也可将Y与Ho和Er分离。     

P507萃取色谱法分离镓、铟及其测定

2-乙基已基磷酸-2-乙基己基酯(P507)已广泛用于萃取分离稀土元素,用于萃取镓、铟、铊,在盐酸或硫酸介质中均具有较好萃取性质,易于反萃取。鉴于分析分离中萃取色谱法较萃取分离更为实用,我们进一步研究了萃取色谱分离镓、铟及其伴生元素的方     

Phenol removal from aqueous solution by adsorption and ion exchange mechanisms onto polymeric resins

The removal of phenol from aqueous solution was evaluated by using a nonfunctionalized hyper-cross-linked polymer Macronet MN200 and two ion exchange resins, Dowex XZ (strong anion exchange resin) and AuRIX 100 (weak anion exchange). Equilibrium experimental data were fitted to the Langmuir and Freundlich isotherms at different pHs. The Langmuir model describes successfully the phenol removal onto the three resins. The extent of the phenol adsorption was affected by the pH of the solution; thus, the nonfunctionalized resin reported the maximum loading adsorption under acidic conditions, where the molecular phenol form predominates. In contrast both ion exchange resins reported the maximum removal under alkaline conditions where the phenolate may be removed by a combined effect of both adsorption and ion exchange mechanisms. A theoretical model proposed in the literature was used to fit the experimental data and a double contribution was observed from the parameters obtained by the model. Kinetic experiments under different initial phenol concentrations and under the best pH conditions observed in the equilibrium experiments were performed. Two different models were used to define the controlling mechanism of the overall adsorption process: the homogeneous particle diffusion model and the shell progressive model fit the kinetic experimental data and determined the resin phase mechanism as the rate-limiting diffusion for the phenol removal. Resins charged after the kinetic experiments were further eluted by different methods. Desorption of nonfunctionalized resin was achieved by using the solution (50% v/v) of methanol/water with a recovery close to 90%. In the case of the ion exchange resins the desorption process was performed at different pHs and considering the effect of the competitive ion Cl⁻. The desorption processes were controlled by the ion exchange mechanism for Dowex XZ and AuRIX 100 resins; thus, no significant effect for the addition of Cl⁻ under acidic conditions was observed, while under alkaline conditions the total recovery increased, specially for Dowex XZ resin.     

Removal of nickel from water and synthetic nuclear power plant coolant water by ion exchange resins

A method for the removal of nickel from waste water by adsorption process on ion exchange resin was studied. The percentage removal of nickel depends upon the contact time, pH and dose of adsorbent. Adsorption of nickel on ion exchange resins obeys Freundlich adsorption isotherm. The applicability of Lagergren kinetic model has also been investigated. In order to understand the adsorption behavior of nickel, a number of batch experiments were conducted at various pH values. The results show that the adsorption is maximum in the pH range 2 to 8. The studies showed that the ion exchange resins IRN77 and SKN1 can be used as an efficient adsorbent material for the removal of Ni(II) from water and coolant water.     

新型树脂基水合锰氧化物对水体中磺胺嘧啶的降解去除

以大孔强碱阴离子交换树脂D201为载体, 采用离子交换和氧化还原方法制备了一种新型树脂基水合锰氧化物材料HMO-201. 考察了不同pH、 离子强度和溶解性有机质(DOM)含量条件下, 该材料对水体中磺胺嘧啶(SD)的去除能力. HPLC-MS分析表明, SD的高效去除是通过HMO-201的降解而非吸附方式实现的. 实验结果表明, pH为1.0时HMO-201在120 min内对0.01 mmol/L SD的去除效率为99.9%, 反应符合表观一级动力学模型; 体系的离子强度和DOM含量变化对SD的去除效率均无显著影响. 模拟环境离子强度和DOM浓度, 连续10批次实验中SD废水的去除效率在240 min内均大于99%; HMO-201的柱动态降解装置连续处理SD溶液2000床体积, 依然未检出SD. 表明HMO-201材料具有较稳定的重复利用性, 对环境中普遍存在的磺胺类抗生素药物具有着高效的降解去除效果, 具有广泛的应用前景.     

Regeneration of cobalt-contaminated activated carbon by supercritical carbon dioxide extraction

A mixture of Di-(2-ethylhexyl) phosphoric acid (D2EPHA) and n-hexane or methanol is used as the extractant solution for extracting cobalt from activated carbon using supercritical carbon dioxide extraction technology. In this work, a semi-continuous pilot unit of SFE is employed to conduct the extraction. In order to feed the viscous extractant by HPLC pump, n-hexane or methanol is added as a diluent to reduce the viscosity of the extractant. The amount of cobalt removed along the time course of the extraction is recorded and plotted as an extraction curve. A kinetic model is also established and fit to the extraction curve, and the obtained parameters of the model are used to explain the regeneration mechanism. The effects of temperature ranged from?40 to?80?°C and the effect of the concentration of diluents on the extraction are investigated and discussed based on the established model. It is also found that the removal of cobalt ions reaches a maximum; this varies with the operational conditions and is known as maximum removal efficiency. It is presumed that the maximum removal efficiency is affected by the adsorption kinetics of the extractant and the rate of ion exchange between the extractant and metal ions on the surface of the activated carbon. After increasing the extraction temperature from?60 to?80?°C it is observed that the maximum removal efficiency is greatly increased, presumably resulting from the diminishing competitive adsorption between the extractant and diluents. The established model can help to reveal the extraction mechanism and to promote maximum removal efficiency for regenerating activated carbon without secondary pollution.     

Adsorption of Zinc and Cyanide from Cyanide Effluents on Anionic Ion-exchange Resin

The adsorption of zinc and cyanide from cyanide effluents onto strong and weak basic anion exchange resins was studied in a batch adsorption system. Factors influencing the adsorption rates such as resin selection, resin amounts, contact time and temperature were studied and scanning electron microscopy-energy disperse spectroscopy(SEM-EDS) was used in the analysis. The present study shows that the adsorption capacity of resin 201×7 is better than that of resin 301. The adsorption process was relatively fast and came to equilibrium after 60 min. The kinetic data were analyzed with three models and the pseudo-second-order kinetic model was found to agree with the experimental data well. The equilibrium data could also be described well by Langmuir isotherm model. Thermodynamic parameters such as enthalpy change(ΔH⁰), free energy change(ΔG⁰) and entropy change(ΔS⁰) were calculated and the adsorption process was spontaneous and endothermic.     

pH和盐对树脂吸附芳香酸的影响研究

通过三甲胺修饰超高交联聚苯乙烯树脂NJ-00制备了一种新型树脂(NJ-03),树脂性质表征说明,通过改性季胺基被成功引入,树脂骨架上增加了一定数量的碱性基团。研究了pH、盐浓度对芳香酸类化合物在NJ-03树脂上吸附的影响,并与商品大孔强碱阴离子交换树脂D-201以及大孔弱碱阴离子交换树脂D-301进行对比,探讨了pH和盐浓度影响吸附的机理。     

D301大孔树脂吸附钒(V)的性能研究

研究了D301大孔树脂对钒的吸附性能.结果表明,pH值对D301树脂吸附钒的影响很大,与钒在溶液中的赋存状态有关,且在pH=2时吸附效果最好:测得吸附热力学参数分别为:△H=8.97kJ/mol,△G_(313)=-5.69kJ/mol,△G_(303)=-5.2kJ/mol,△G_(293)=-4.9kJ/mol,△S=46.84J/mol·K.等温吸附服从Freundlich经验式;考察了溶液浓度、搅拌速率对交换过程的影响,并对实验数据运用相关理论模型进行拟合,结果显示钒(V)在D301树脂上吸附交换过程控制步骤为颗粒扩散控制,反应级数n为0.2391.     

同时吸附油和六价铬离子复合材料的制备及性能

以亲油疏水型三元乙丙橡胶(EPDM)作为基体, 焙烧Fe2O3和阴离子交换树脂201Х7作为填料, 利用熔融共混的方法, 制备一种可以同时吸附油和六价铬离子的用于污水处理的复合材料, 这种材料能够悬浮于油水界面处. 当焙烧Fe2O3和阴离子交换树脂的用量比例不同时, 材料吸附性能变化很大. 实验结果表明, 在保证复合材料密度介于油水密度之间的前提下, 随着焙烧Fe2O3含量的增加, 材料的吸油性能不断增大; 随着阴离子交换树脂含量的增加, 材料对六价铬的吸附性能不断增加. 在油水共存体系中, 复合材料对两种污染物的吸附率同时达到最佳时, 两种填料的比例可以确定, 因油品的不同而不同. 在油水共存体系中, 复合材料对油和六价铬的总吸附能力要远大于复合材料分别在单一吸附介质中的吸附能力.     

新型树脂基水合氧化铁对水体中微量砷的吸附性能研究

将水合氧化铁固载于凝胶型强碱阴离子树脂N201上并合成出新型除砷吸附剂N201-Fe.研究了不同实验条件下N201-Fe对去除水溶液As(V)的影响.实验结果表明,N201-Fe对砷的吸附受pH值的影响较小;N201-Fe对As(V)具有很高选择性,在Cl-、HCO3-、SO42-等竞争离子共存时,N201对As(V)的去除率不到2%,而N201-Fe却高达90%.N201-Fe对As(V)的高选择性归因于N201-Fe中水合氧化铁与As(V)之间的络合配位能力及树脂表面的Donnan膜效应.静态吸附实验表明N201-Fe吸附As(V)的等温线符合Freundlich模型,热力学结果显示,该吸附过程为吸热过程.动态穿透实验表明,模拟水中的As(V)经N201-Fe处理后可达到中国和美国的饮用水标准,且N201-Fe的吸附处理量较N201提高30多倍.     

巯基树脂对重金属离子的吸附性能

研究了自合成的巯基树脂对重金属离子Pb^2 、Cu^2 、Cd^2 ．Ni^2 、Co^2 的吸附容量、吸附动力学、等温吸附过程等静态吸附性能，同时研究了影响吸附的因素和吸附机理．结果表明，该树脂对软酸型重金属离子吸附容量高．pH=5．0-5．7，低温有利于吸附，树脂对各重金属离子等温吸附在实验浓度范围内均符合Langmuir和Freundnch方程．吸附机理研究表明，巯基与重金属离子发生了离子交换和配位反应，化学吸附起支配作用。