首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 500 毫秒
1.
弱碱性阴离子树脂的优点是容易再生,但至今未见其再生动力学研究的报道。Hll通过光学方法观测到再生时树脂相内的动边界。从而肯定了用NaOH再生盐式弱碱性阴离子树脂是遵守层进机理的。以前的研究工作肯定了可以根据溶液中反离子浓度的变化来确定离子交换树脂的转换度,得到了适用于有限浴及离子交换剂颗粒半径保持恒定或不断随交换反应进行而变化条件下的速度表达式。适用于不同条件的由已反应层内的扩散控制的层进机理的离子交换反应的速度方程分别为: 1.无限浴及交换剂颗粒半径恒定条件下E(t)=1-3(1-X)~(2/3)+2(1-X)=6λD_eC_B~0t/(?) (1) 2.有限浴及交换剂颗粒半径恒定条件下  相似文献   

2.
离子色谱分析中,影响离子交换选择性的因素颇多[1]。除固定相的基本结构外,尚有两个最重要的因素,即固定相上的离子交换功能活性基团结构和淋洗条件。近年来利用静态涂覆液态离子交换剂的阴离子分离柱,我们研究了不同结构季铵型和季 型阴离子交换剂对阴离子交换选择性的影响[2,3],结果表明,它们皆具有相当不同的离子交换选择性的分离效果[4]。为进一步研究交换剂结构效应和选择优化淋洗条件,本文报道以疏水性更大氮杂三芳稠环结构的季铵化合物,即N-十六烷基-β-萘喹啉溴化 盐为交换剂涂覆于国产NGW-04苯乙烯-二乙烯苯共聚体白球上,制备了阴离子色谱分离柱,选择九种有机酸及其盐配制的淋洗液进行离子色谱性能研究,着重讨论了它们的分离效应。  相似文献   

3.
甲基化聚胺型硅基强阴离子交换剂用于生物大分子的分离   总被引:1,自引:0,他引:1  
用聚胺键合法合成了聚胺型碱性硅胶基质,进一步甲基化后制得了强阴离子交换剂,该强阴离子交换剂将硅工礅子交换剂和树脂型离子交换剂的优点有机地结合起来,具有稳定性好,使用PH值范围宽(PH1-12),柱渗透性好和优点,可理想地用于生物大分子和蛋白南,多肽和酸等的分离。型碱性硅胶  相似文献   

4.
用流动注射分析法测定强碱性阴离子交换树脂的交换容量   总被引:1,自引:0,他引:1  
李永生  董宜玲 《分析化学》2004,32(6):787-790
建立了快速测定微量氯离子的FIA分光光度法和快速测定强碱性阴离子交换树脂交换容量的FIA法。本方法将离子交换微型柱导入树脂交换容量的测定中 ,不但获得了很好的精度 (RSD <0 .9% ) ,而且使测定效率提高了近 30倍。优选实验得到的最佳测定条件为再生液流速 0 .5mL/min ,再生剂用量 :333mL/ g,再生剂浓度 :3.0 % (W /V) ;样品液流速 :1 .5mL/min ;树脂交换容量测定温度 :2 5℃± 5℃。  相似文献   

5.
本文研究了磷酸钦─磷钨酸铵(TiP-AWP)的合成,离子交换性能及化学结构等方面的性质。实验结果表明,该交换剂对CS 具有很高的选择性和交换容量,在0.1mol/LNO3介质中,该交换剂对CS 的交换容量可达0.95mmol/g,在1AW模拟废液中,对Cs 离子仍保持较高的交换容量。动态研究表明,该物质交换、淋洗、再生后交换容量基本不变,结构完整,对于放射性核素的分离和提取具有重要的意义。另外,该交换剂具有良好的辐射和热稳定性。  相似文献   

6.
以交联聚乙烯醇为载体的阴离子交换剂的合成与性能研究   总被引:6,自引:0,他引:6  
大孔乙酸乙烯酯-异氰尿酸三烯丙酯共聚物树脂经醇解生成亲水性的交联聚乙烯醇,然后相继与环氧氯丙烷和二乙胺反应,合成出含二乙基氨基羟丙基的阴离子交换剂,研究了交联聚乙烯醇环氧基化的最佳条件,发现以二甲基亚砜作溶剂能够显著地提高活化程度,反应时间以3h为最佳,并研究了该阴离子交换剂的交换量、亲水性、热稳定性、溶胀稳定性,发现它具备常压分离蛋白质所需的基本性能,是较为理想的生化用的离子交换剂。  相似文献   

7.
离子交换纤维对亚硫酸法糖汁脱色性能研究   总被引:3,自引:0,他引:3  
研究了强碱性阴离子交换纤维对亚硫酸法清净糖汁的脱色性能.对沉清工段清汁的脱色效果和影响因素进行了研究.结果表明,阴离子交换纤维对沉清汁的脱色效果明显,脱色后清汁色值低于30 oSt.再生液洗脱再生反复使用90次后,脱色效果达84%.与717强碱性苯乙烯系阴离子交换树脂相比具有脱色容量高、脱色速度快、再生速度快和抗污染能力强等优点.通过离子交换纤维的脱色处理,亚硫酸法清净糖汁可以达到制备优质糖的要求.  相似文献   

8.
全固定化试剂流动注射化学发光测定铜   总被引:5,自引:3,他引:5  
采用离子交换固定法把Luminol(Lu),CN^-固定在阴离子交换树脂上,串入流动注射系统中,当一定量洗脱剂被注入阴离子交换柱时,洗脱下来的Lu和CN^-与分析物Cu^2+发生化学反应,产生化学发光,实现对Cu^2+的在线检测。本法检出限为1.3×10^-9g/mL,线性范围为4.0×10^-9-6.0×10^-6g/mL,RSD为3.4%,单次测定在1min内能完成。已用于井水中铜的测定,结果  相似文献   

9.
球状再生纤维素离子交换剂的制备   总被引:7,自引:0,他引:7  
本文以球状再生纤维素为基体,采用一种新颖的合成方法,成功地制备出一系列阴离子和阳离子交换剂。作者对合成条件进行了正交优化,筛选出最佳的合成条件,所制备的交换剂具有疏松的大孔网状结构和良好的水力学性能,对大分子有高的交换容量,可应用于蛋白质,酶等大分子的分离提纯。  相似文献   

10.
阴离子交换纤维的制备及其对铀的吸附性能研究   总被引:3,自引:0,他引:3  
研究了以聚丙烯纤维为基体辐射接枝乙烯吡啶制备阴离子交换纤维。这种纤维可用于提取铀,其吸附铀速度比颗粒状离子交换剂要快。  相似文献   

11.
The adsorption of isomaltotriose from aqueous solution on Ca2+ resin was investigated.The adsorption isotherm and the rate curve were determined. The pseudo-first-order model,pseudo-second-order model and the intraparticle diffusion model were used to predict the rate constants of adsorption. The activation energy of adsorption has been also evaluated using the pseudo-second-order rate constants. The results showed that the adsorption of isomaltotriose onto Ca2+ resin is an exothermically activated process. The adsorption isotherm can be described by Langmuir equation. The pseudo-second-order model can fit well to the adsorption rate curve of isomaltotriose onto Ca2+ resin. It suggests that the adsorption of isomoltotriose onto Ca2+ resin involve chemical adsorption.  相似文献   

12.
粘度法研究壳聚糖对外加盐的敏感性   总被引:11,自引:0,他引:11  
聚电解质的特性粘度对外加盐的响应是反映聚电解质对外加盐敏感性的一个重要特征,通过分别测定壳聚糖在不同小分子强电解质(NaCl、KCl、CaCl2、BaCl2)和相同小分子强电解质(NaCl)但不同离子强度的稀溶液粘度,得到:(1)壳聚糖特性粘度与外加盐的离子强度的平方根的倒数成正比;(2)不同小分子强电解质中阳离子对壳聚糖特性粘度的影响次序是Na+>K+>Ba2+>Ca2+.同时,测算了壳聚糖在不同外加盐浓度中的Mark Houwink方程参数α,发现其值皆大于05,得到了壳聚糖分子链的僵硬性参数B的值为0074,揭示了壳聚糖具有较大的分子链刚性和抗盐性能.  相似文献   

13.
The spectrophotometric determination of Ca2+ with chlorophosphonazo III (CPN) has been carried out by a circulatory flow injection (FI) method. A cation-exchange mini-column for the on-line regeneration of the main reagent was incorporated in this FT system, allowing a repetitive determination of Ca2+. A solution of 4.0 x 10(-5) M CPN in a 0.05 M acetate buffer (pH 5.0) in a single reservoir (50 ml) was continuously circulated at a constant flow rate of 1.5 ml min(-1). Into the stream, an aliquot (20 microl) of a sample containing Ca2+ was quickly injected by means of a 6-way valve. The complex formed was monitored spectrophotometrically at 670 nm in the flow system. Then, the stream passed through a cation-exchange column, which was introduced after the flow-through cell. A successful ligand-exchange reaction of Ca2+ between the CPN reagent and a cation exchanger, as well as a simultaneous regeneration of the free reagent took place. The stream then returned to the reservoir. The regeneration and recycling of the CPN reagent allowed as many as 300 repetitive determinations of 2.5 mg l(-1) Ca2+ solutions with the same 50 ml circulating solution.  相似文献   

14.
水溶性丙烯酰胺类共聚物 ,作为粘度改性剂 ,在工业上已得到广泛应用 .特别近年来 ,它们大量应用于石油工业强化采油技术 ,引起了人们很大的重视[1] .目前 ,这类用途的聚合物 ,主要在聚丙烯酰胺结构中 ,引入阴离子组分和不断增高产物分子量的方法 ,以提高聚合物溶液粘度和增粘效果 ,然而 ,在二价金属离子 (如Ca2 + ,Mg2 + 等 )存在下 ,羧酸阴离子型丙烯酰胺类共聚物很容易络合发生沉淀 ,从而失去增粘作用[2 ] .同时这类聚合物中酰胺基不稳定 ,易发生水解反应转化为羧酸基 ,并随温度升高而加剧[3 ] ,因此在温度较高的应用条件下 ,二价金属…  相似文献   

15.
1. INTRODUCTION Oligosaccharide is a carbohydrate comprising 2~9 monosaccharide units linked together by glucoside bond. In the digestive system of humankind, there exits no enzyme for the hydrolysis of oligosaccharides. So it can be used by bifidobacteria in large intestine, and lead to some special physiological function [1]. Oligosaccharide exits in many plants, for example, Morinda officinalis, a precious herb growing in south China. In this herb, four oligosaccharides with the funct…  相似文献   

16.
The Mg2+ ion content in the surface layer of calcite in relation to the Mg2+ ion content in Ca-45 labelled solution was determined by Ca2+-Mg2+ ion exchange process. It was found that the increase of the molar ratio Mg/Ca in the surface due to increase of Mg2+ concentration in solution is decreasing significantly when approaching ratios of Mg/Ca ~ 1 and ~ 3. The experimental exchange isotherm can be used to relate the Mg/Ca molar ratio of solutions to that of the surface layers of calcite.  相似文献   

17.
1.INTRODUCTIONThemixedbedofionexchangeisanecessnywatertreatmentunitfortheProduchonofpurewaterandsuperpurewaterinelectricindustryandthermalpowerplant.Ingeneral,inthemixedbed,theionexchangeresinsconsistofthestronglyacidicionexchangeresininfree-acidformandstronglybasicionexchangeresininfree-baseform.TheexhaustedresinswillberegeneratedbyusingthestrongacidandstrongalkalirespechvelyThiskindofregenerationmethodwithacidandalkalihasfollowingdefectsf1.TheutilizationefficiencyofregenerantSisvarylow…  相似文献   

18.
The suspension pH at a given concentration of hydroxyapatite (HAP) decreased with the concentration of calcium chondroitin-6-sulfate (CaChs), whereas it increased with the concentration of sodium chondroitin-6-sulfate (Na2Chs). The former effect is due to the increase in the concentration of H+ by ion exchange between H+ on the surface of HAP and Ca2+ of CaChs, and the latter is due to the protonation of phosphate ion (Pi) released from the surface of HAP. The absorbed amount of chondroitin-6-sulfate anion (Chs) by HAP was higher with CaChs than with Na2Chs over the concentration range examined. The equilibrium concentration of Pi decreased with increasing concentration of added CaChs because the concentration of free Ca2+, which dissociates from CaChs, regulates the free concentration of Pi through the restriction of the solubility product of HAP (Ksp). In contrast, that in the presence of Na2Chs increased with increasing concentration of added Na2Chs owing to the anion exchange between Chs and Pi of the HAP surface. The total concentration of Ca2+, which was released from HAP into the solution phase, increased after passing through a minimum with increasing concentration of added Na2Chs. That is, the concentration of Ca2+ free from Chs decreased with an increase in the concentration of released Pi owing to the restriction of the solubility product, whereas that of Ca2+ bound by Chs increased with increasing concentration of added Na2Chs through the ion exchange of Na+ with Ca2+. It was confirmed by the dialysis method that the value of Ksp was almost constant around 10, although HAP dissolves incongruently in the presence of Na2Chs.  相似文献   

19.
In this paper,the self-regeneration process of the mixed resins consisting of cation and anion ion exchangers in the electrolialyser of the packed bed is analyzed,and an electric regeneration method is put forward to supply the desalinated water by mixed bed.The electric regeneration technology is a new one used for regeneration of the exhausted ion exchangers in the mixed bed,instead of the traditional regenerating process by using acid and alkali liquor.Electric energy is consumed to regenerate the ion exchangers loaded by salts from water treatment without any chemicals-acid and alkali.The advantage of the electric regeneration process exhibited convenient operation,no discharge any waste,and therefore no pollution to the receiving water body and the environmental ground.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号