弱碱性离子交换树脂D301分离低浓度甲酸的研究

采用D301弱碱性离子交换树脂对水溶液中低浓度甲酸进行分离。静态条件下考察了时间、温度、振荡速率和树脂用量对分离效果的影响,获得了交换等温线;动态条件下考察了不同高径比、流速、温度、浓度下动态穿透曲线;研究了树脂再生效果与稳定性。初始浓度573mg/L的甲酸废水,在树脂用量2.5g/L、温度35℃、振荡速率160r/min条件下,最大交换量为154.16mg/g;其交换等温线符合Langmuir方程,热力学平衡方程计算得G<0,H=10.25kJ/mol,S>0,表明该吸附过程是自发的、吸热、熵增加的过程。交换过程中颗粒扩散是离子交换的主要速率控制步骤,表观活化能与反应级数分别为5.983kJ/mol和0.378。     

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。     

含胍基强碱性阴离子交换树脂的合成及应用

以大孔型氯甲基化交联苯乙烯-二乙烯基苯聚合物(D301-Cl)为原料,与1,1,3,3-四甲基-2-正丁基胍(BuTMG)进行季铵化反应,合成了一种强碱交换量为2.65mmol/g含胍基的强碱性阴离子交换树脂(SG).合成的SG树脂经红外光谱表征,并评价了该树脂在水中的热稳定性.结果表明:SG树脂在100℃去离子水中保持100h交换量仅下降9.8％,优于商业通用的D201强碱性阴离子交换树脂.考察了SG树脂对碳酸丙烯酯(PC)与乙醇酯交换合成碳酸二乙酯(DEC)的催化性能,发现PC转化率达21.6％,DEC的选择性达到98.0％.     

钯/离子交换树脂催化硝基化合物加氢的性能及其结构研究

制备了强酸铁阳离子交换树脂(-SO_2,D72),弱酸性阳离子交换树脂(-COOH,D152), 强碱性阴离子交换树脂[-+~N(CH_3)_2,D290],弱碱性阴离子交换树脂[-N(CH_3)_2,D370]及螯合树脂[-N(CH_2COO-),D401]负载钯催化剂,测定了它们催化硝基化合物加氢的活性,其中D290-Pd的催化活性较好。XPS结果表明,D290-Pd催化剂中钯是与功能基-~+N(CH_3)_3结合而负载于树脂上的,起催化作用的是金属态钯;这就成功地解释了离子交换树脂负载的钯催化剂的功能基效应和配位基效应。     

离子交换剂文摘

由茜素氟兰—镨(Ⅲ)络合物改性的阴离子交换树脂用于选择性吸附氟离子Chikuma, M.; Nishimura, M.;Reactive Polym. 1990, 13(1—2), 131由阴离子交换树脂(Amberlite IRA 400)和茜素氟兰(AFB)的镨络合物制得了选择性吸附F~-的功能树脂。AFB-Pr(Ⅲ)通过离子交换和与阴离子交换树脂的骨架之间的非静电的相互作用被固定到树脂上。用AFB—Pr(Ⅲ)络合物改性的树脂(AFB—Pr树脂)     

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.     

Degradation and Removal of Suifadiazine from Waters by a Novel Polymer-supported Hydrous Manganese Dioxide(HMO)

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.     

含长碳链间隔臂结构的强碱性阴离子交换树脂的合成及热稳定性

研究了一种含长碳链间隔臂结构的强碱性阴离子交换树脂的新合成方法.评价了该树脂在水中的热稳定性.结果表明,以苯乙烯-二乙烯基苯共聚白球和1,3-噁嗪-2-酮为原料,季铵型离子液体为催化剂,得到带有胺丙基的苯乙烯-二乙烯基苯共聚珠体,再用甲酸和甲醛N-甲基化,溴乙烷季铵化,可以生成强碱交换量为1.86mmol/g强碱阴离子交换树脂.含长碳链间隔臂结构的OH~-型阴离子交换树脂在100℃去离子水中保持720h交换量仅下降11.83%,好于商业通用的强碱阴离子交换树脂.     

离子交换树脂去除模拟放射性废液中的铯

核电站放射性废液组成复杂,其中¹³⁷Cs、⁹⁰Sr和⁶⁰Co是放射性废液处理的主要目标。 本文采用稳定同位素模拟放射性废液,研究了Cs⁺离子在强酸性阳离子树脂IRN97中的交换等温线、动力学特性以及固定床穿透行为,探讨了共存的硼酸和Sr²⁺、Co²⁺等核素离子对Cs⁺离子交换行为的影响。 结果表明,废液中存在的高浓度硼酸在一定程度上会减小树脂对Cs⁺的交换量;与共存的Sr²⁺和Co²⁺离子相比,虽然Cs⁺的交换速率快,但树脂对Sr²⁺和Co²⁺的选择性更高,因此在达到交换平衡状态下,Sr²⁺和Co²⁺的交换容量大于Cs⁺;在采用固定床吸附柱进行的动态吸附中,提高Cs⁺的进水浓度可以提高树脂的利用率。     

钠型斜发沸石在K^＋-Na^＋-NH4^＋和K^＋-Na^＋-Ca^2＋水溶液体系中的离子交换平衡

研究了K -Na -NH4 和K -Na -Ca2 水溶液体系与钠型斜发沸石的离子交换平衡。分别测定出以上两个体系在25℃、50℃和75℃下的离子交换平衡数据,利用平面三角图绘制表达出三元离子交换平衡等温线,并计算出沸石对体系中离子的分离因数。结果表明,在K -Na -NH4 溶液体系中,K 的分离因数在3以上,NH4 的分离因数在1~3之间,Na 的分离因数小于1,斜发沸石的离子交换选择顺序是K >NH4 >Na ,且低温有利于K 的交换,高温时NH4 的交换能力增强;在K -Na -Ca2 溶液体系中,K 的分离因数大于8,Na 的分离因数在1左右,Ca2 分离因数小于1,沸石的离子交换选择顺序是K >Na >Ca2 ,其中Ca2 属于部分交换,Ca2 对沸石对K 的交换选择性影响不大,且低温有利于沸石对K 的交换。     

THE EFFECT OF IONIC STRENGTH ON THE UPTAKE OF TAURINE ON A STRONG-BASIC ANION EXCHANGE RESIN

Studied the effect of ionic strength on the uptake of taurine on a strong-basic anionexchange resin. The batch phase equilibrium experiments of ta urine on the anion exchange resin D290 were conducted at different ionic strength, and then the amounts of uptake of taurine on the resin at different pH were determined. The ion exchange mechanisms of taurine on the anion exchange resin at different pH were discussed. Experimental results showed that with increase of the ionic strength of solution, the adsorbed amount of taurine on the resin D290 decreased; Adding small amounts of NaOH or HCl into the system of taurine aqueous solution/D290 anionresin would make the amount of taurine taken up on the resin to decrease due to the competition uptakes of hydroxyl ion with taurine or the decrease in the amount of absorbable zwitterions of taurine in the solution and excluding the cations of taurine from the anion resin.     

THE EFFECT OF IONIC STRENGTH ON THE UPTAKE OF TAURINE ON A STRONG-BASIC ANION EXCHANGE RESIN

1. INTRODUCTION Taurine (NH2CH2CH2SO3H) is one of the most important amino acids in the human body, and plays an important role in a variety of physiological functions, pharmacological actions and pathological conditions, such as in controlling epilepsy, hypertension and arrhythmia. It is also often used to recover osmotic pressure and promote cerebrum growth [1,2]. As one of amino acids, taurine had the amphoteric characteristic which can be utilized in the ion-exchange technique to e…     

弱碱性阴离子交换树脂的本征解离常数

根据Donnan膜平衡模型及外推法提出弱碱性阴离子交换树脂本征解离常数的测定方法。并测得大孔丙烯酸系弱碱性阴离子树脂D705的本征解离常数的负对数pK_b~(int)为3.72士0.04,结果表明,Marinsky在测弱酸性阳离子树脂的pK_a~(int)时,引入交换剂相中H~+及Na~+的活度系数相等的假定并非必要。     

弱碱性和强碱性阴离子交换树脂的离子交换平衡的比较SO2-4-Cl——NO-3体系

本文详细地比较了在弱碱性和强碱性阴离子交换树脂上, SO_4~(2-)-Cl~-、NO_3~--Cl~-及NO_3~--SO_4~(2-)二元交换的等温线和修正选择系数。实验测定及理论计算了上述三种二元交换反应的标准自由能的改变量。测得了在弱碱性树脂上的SO_4~(2-)-Cl~--NO_3~-三元交换的等温线。适用于强酸性和强碱性树脂的从二元交换平衡数据推算三元交换平衡数据的方法推广应用于弱碱性树脂。     

低浓度下离子交换树脂吸附氨基酸的机理

详细地研究了在低浓度下, 酸(碱)式或盐式强酸性阳离子和强碱性阴离子交换树脂吸附氨基酸的机理·结果表明, 氨基酸通过离子交换、离子转移和物理吸附等三种机理被离子交换树脂吸附。     

DETERMINATION OF ION EXCHANGE EQUILIBRIUM CONSTANTS FOR THE WEAK ACID CATION AND THE WEAK BASE ANION EXCHANGE RESINS

The general procedure based on the potentiometric titration has developed.According to the procedure,the rational equilibrium constants of the ion exchange reactions RH/Na,RH/Ca,RH/Sr,RH/Ba for the weak acid cation exchange resin D725 and ROH/Cl for the weak base anion exchange resin D705 have been determined.     

碱性氨基酸离子交换平衡特性的研究

研究了碱性氨基酸与001×7阳离子交换树脂的离子交换平衡特性。测定了001×7树脂对碱性氨基酸两种价态离子的选择性吸附系数,并考察了pH和碱性氨基酸的浓度对平衡吸附量的影响,确定了离子交换的最佳pH 和碱性氨基酸的浓度。     

DIFFUSIVITY OF RARE EARTH ION IN POROUS ION EXCHANGE RESINS

TheporousionexchangeresinshavebecomeanimportantreactivepolarermaterialwhicharewidelyappliedinindustrialoperationsHowever,afewstudi..[l--3]reportedtheintraparticlediffusivityofporousionexchangers.Theionexchangedisplacementprocessonporousresinbedforseparationofrareearthsistheoneofthebestwaystoenhancetheeffectivityofthismethod.TounderstandthediffusionoftheionintheresinisveryavailablefolimproVingtheprocess.EXPERIMENTAL1.Pre--experimentsAllthereagentsusedareA.R.grade.152'154Euisusedasaradiot…     

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.