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1.
ABSTRACT

A number of inorganic ion exchange materials that are commercially available or under development were evaluated for the removal of strontium and cesium from a simulated groundwater found in the Hanford waste storage area using a groundwater simulant spiked with either 89Sr or 137 Cs. The most promising materials for strontium were found to be a sodium titanosilicate from Texas A&M University closely followed by two titanium silicate pharmacosiderites obtained from AlliedSignal. The most promising materials for the selective removal of cesium from the simulant was again the sodium titanosilicate followed by an alumina-pillared montmorillonite clay obtained from Laporte Industries Ltd. The ion exchange kinetics were shown to be very rapid for both the titanosilicate and the pharmacosiderite, whilst the alumina-pillared montmorillonite had slower kinetics more comparable to those of the zeolite AW500.  相似文献   

2.
ABSTRACT

Ion exchange isotherms for the ion-pairs Li+ -Cs+, Na+ -Cs+ and K+ -Cs+ have been measured for a cesium selective resorcinol—formaldehyde polycondensate resin synthesized in the laboratory- The equilibrium data have been used to calculate the thermodynami c equilibrium constants as well as standard free energies of ion ex change and thus arrive at a selectivity series for the above ions- The high selectivity towards cesium as compared to other alkali metal ions has been discussed in the 1ight of existing theories and models of ion ex change phenomena.  相似文献   

3.
根据活性炭对L-苯丙氨酸的选择吸附特性,通过活性炭吸附及氨水、乙醇溶液解析从酶转化液中成功地分离提取了L-苯丙氨酸、L-天冬氨酸,并利用717#树脂脱色和去杂离子,浓缩结晶得到符合标准的L-苯丙氨酸晶体。整个工艺路线对L-苯丙氨酸的洗脱收率接近100%,原料总收率大于70%。  相似文献   

4.
袁业明 《水处理技术》1995,21(3):142-144
本就上海化工厂新型膜的开发作一概述。给出了3363、3364和3365异相膜的测试数据。目前该厂离子交换膜的年产量已达3.8×10^5m^2。  相似文献   

5.
张培均 《大氮肥》2009,32(5):319-320
阳床离子交换树脂被Fe3+污染、混床离子交换树脂被有机物和铵污染后,交换能力下降,通过问题分析,利用再生剂进行复苏处理,恢复树脂活性。  相似文献   

6.
研究了碱土金属离子在D001树脂与8-羟基喹啉三氯甲烷溶液间的平衡常数O-tK的测定。其值依Mg、Ca、Sr、Ba次序减小。并得出萃取剂浓度[HA]。与金属离子在两相分配的关系。  相似文献   

7.
ABSTRACT

The effect of nitric acid concentration on the selectivity of a novel extraction chromatographic resin consisting of an octanol solution of 4,4′(5′)-bis(t-butyl-cyclohexano)-18-crown-6 sorbed on an inert polymeric support for strontium over a number of alkali, alkaline earth, and other metal cations was evaluated. The effect of macro quantities of selected elements on strontium retention by the resin was also examined. The resin is shown to exhibit excellent selectivity for strontium over nearly all of the test elements; only lead and tetravalent neptunium, polonium, and plutonium show significant affinity for the material. In addition, concentrations of calcium or sodium ion up to ~ 0.1 M. are shown not to diminish the sorption of strontium appreciably. Several useful radiochemical separation schemes devised on the basis of the results obtained are described.  相似文献   

8.
ABSTRACT

The uptake of tri-, tetra- and hexa-valent actinides as well as of pertechnetate anions by some new multifunctional ion exchange resins has been investigated. The new resins, identified as Diphonix A, for anionic Diphonix, contain the same geminally substituted diphosphonic acid groups bonded to a styrenic-based polymer matrix as the regular Diphonix resin, plus strong base anion exchange groups such as the tetraalkylammonium (Diphonix A - Type 1 resins) or the quaternized pyridinium (Diphonix A - Type 2 resins) groups. Our uptake measurements have shown that the Type 2 Diphonix A resins are as effective as the regular Diphonix resin in the rapid uptake of actinides from acidic solutions, while at the same time sorbing pertechnetate anions in a manner comparable to existing commercial anion exchange resins. The failure of the Type 1 Diphonix A resins to perform equally well has been explained as a consequence of the mutual interaction of adjacent diphosphonic acid groups and tetraalkylammonium groups. Uptake data have also been obtained with Se(IV). The behavior of the Diphonix A resins toward Se(IV) uptake in acidic solutions is comparable to that of commercial anion exchange resins.  相似文献   

9.
ABSTRACT

The kinetics of heavy metal ion exchange onto a commercial chelating resin was investigated from the standpoint of the swelling-shrinking experienced by the resin bead during the overall ion exchange process. Temporal measurements of the volume variations were carried out for every step of an operational cycle, metal load, elution and regeneration of the ion exchanger, using a microreactor mainly composed by a reaction cell, an optical microscope and an image treatment system. Experimental results were properly fitted to an empirical equation, whose parameters were used to characterize and compare different systems. A pseudosteady state kinetic model, which takes into account the volume variations of the resin bead during the ion exchange reaction, fits fairly well to experimental results, and was used to obtain the effective diffusion coefficients of the metals through the macroporous matrix. Finally, the study of the batch ion exchange kinetics of transition metal cations was completed with a potentiometric titration and other equilibrium determinations. These results were compared with those derived from swelling measurements.  相似文献   

10.
用弱碱性阴离子交换树脂研究了FDPCl离子相互交换作用的动力学关系及有关过程的速率控制步骤并计算了颗粒扩散系数。实验发现,当溶液的质量浓度在10g/L以上时,FDP与树脂之间的交换速率主要受颗粒扩散控制,当溶液的质量浓度≤10g/L时,FDP与树脂之间的交换速率主要受液膜控制。  相似文献   

11.
ABSTRACT

A bifunctional monophosphonic/sulfonic acid ion exchange resin with high capacity has been synthesized. Metal ion studies have been carried out with europium, americium, and ferric nitrate in solutions of varying acidity, with and without sodium nitrate added. The bifunctional resin complexes far higher levels of Eu(III) from 0.5 and 1 N nitric acid than the monofunctional phosphonic acid resin. It is postulated that the sulfonic acid ligand provides an access mechanism for the metal ions into the polymer matrix by hydrating the matrix and preventing its collapse in high ionic strength solutions thus allowing for rapid ionic complexation by the selective phosphonic acid ligands. The bifunctional monophosphonic/sulfonic acid resin has both ligands bound to a polystyrene support. It complexes higher levels of metal ions than a comparable resin differing only by having the monophosphonic acid ligand directly bound to the C-C backbone. Results are compared to a diphosphonic / sulfonic acid resin.  相似文献   

12.
离子交换树脂对有机废水中铜离子的吸附   总被引:20,自引:2,他引:20  
选用多种大孔强酸型离子交换树脂,用于吸附浓集含有机物废水中的铜离子,通过测定各种树脂对铜离子的去除率、不同铜离子浓度和溶液pH值对去除率的影响,以及各树脂再生性能的比较,表明“争光”、“强酸1号”和PK208树脂性能最为突出,效果明显优于其它几种树脂,可用于吸附处理有机废水中的铜离子。  相似文献   

13.
Adsorption studies of several actinides and lanthanides have been carried out by chelating ion exchange resin Dowex A-1. The metal ions studied were Pu4+, Zr4+, UO2 ++, Am3+, Cm3+, Bk3+, Cf3+, Eu3+, and Tm3+. The separation factors between consecutive trivalent actinides and between Am(III) and Eu(III) have been evaluated. Mechanism of adsorption of actinides and lanthanides from different aqueous media has been discussed. An ion exchange procedure for the separation of Pu4+ and UO2 ++ has been developed using this resin.  相似文献   

14.
Tu Maobing  Wei Dongzhi 《化工学报》2000,51(Z1):163-167
The glycosidation reactions of D-glucose with ethanol have been carried out over a reusable and separable heterogeneous catalyst, namely, ion exchange resin. Detailed kinetic data for these reactions are reported. A complex reaction model has been developed for interpreting the data. The reactions were found to be global second-order reactions and first -order with respect to each component. Meanwhile, a new regression method is applied to determine the rate constant from time-dependent profiles.  相似文献   

15.
苯乙烯系离子交换树脂溶出物测定研究   总被引:2,自引:0,他引:2  
本文在自行设计的树脂溶出物动态循环溶出测试装置上,对多种苯乙烯系离子交换树脂溶出物的溶出行为进行了研究,结果表明树脂预处理方式、水的流动和水温对树脂溶出物的溶出行为有较大影响,评判树脂溶出物含量水平应主要依据树脂溶出物的溶出速度。  相似文献   

16.
ABSTRACT

Two novel metastable sodium niobium silicates of the empirical formula: Nal+x?yHy(Nb1?xSix)O3 nH2O, where x=0.33?0.38, y<l+x, n=0,7-l.l (NbSi-Na, 6.0 Å phase), and Na3-x HxNb3Si2O13 nH2O, where x<1.5, n=2.5?3.5 (NbSi-Na, 12.6 Å phase), and two novel potassium niobium silicates: K4?xHxNb4SijO22nH2O, where x<l, n=3.5-4.0 (NbSi-K., 10.0 Å phase), and K1?xHxNbSi4O11nH2O, where x<0.2, n=0.4-0.5 (NbSi-K, 6.05 Å phase), were synthesized in the homogeneous alkaline reaction system NbCl5 - SiO2 - NaOH (KOH) -H2O2 - H2O under mild hydrothermal conditions. The compounds were characterized by elemental analysis, FTIR, TGA, MAS 29Si NMR and X-ray diffraction. It was found that alkali metal niobium silicates have open framework structures. Their ion exchange affinity towards alkali, alkaline earth and some transition metal ions was studied. All alkali metal niobium silicates are moderately acidic ion exchangers. Both sodium niobium silicates show a distinct affinity for Cs+ ion among alkali metal ions, whereas potassium niobium silicate, the NbSi-K, 10.0 Å phase, exhibits affinity for Rb+ ion. The affinity of the sodium niobium silicate, NbSi-Na, 6.0 Å, toward strontium ion in neutral solutions is equal or superior to the best Sr-selective inorganic ion exchangers. The sodium niobium silicate (NbSi-Na, 12.6 Å phase) exhibits extremely high affinity for Pb2+ ion in acidic and neutral media, and both sodium niobium silicates also show a moderate affinity for Hg2+ ion in neutral and highly alkaline media. These exchangers could be promising for the treatment of some specific nuclear waste and contaminated environmental and biological liquors containing lead, mercury and radioactive strontium.  相似文献   

17.
离子交换树脂电再生实验研究   总被引:4,自引:0,他引:4  
赵英  尹连庆  路光杰  杨超 《化工学报》2003,54(9):1330-1333
引 言针对目前离子交换树脂酸碱再生工艺中再生药剂利用率低、再生操作步骤繁多、大量废酸碱液的排放对环境造成污染的弊病 ,借助电渗析概念提出了一种新的离子交换树脂再生方法———电再生 ,即利用水电离出的H+和OH- 离子分别再生失效的阳、阴离子交换树脂 .本实验采用单级三隔室离子交换树脂再生装置对电再生进行了研究 .1 混床树脂的电再生实验关于混床树脂电再生 ,人们已经进行了广泛的研究[1~ 6 ] .所谓电再生实质是填充床电渗析法 ,即去离子 (EDI)净水技术 .它的进水条件苛刻 ,要求反渗透处理后出水 ,填充树脂属于再生后树脂 .…  相似文献   

18.
ABSTRACT

Laboratory scale investigation has been carried out for the optimization of a new process for separation and recovery of Pb/Fe species from automobile battery manufacturing wastewaters. The innovation, based on ion exchange, allows for separation and recovery of the mentioned species by the use of a commercial weak anion resin (Duolite A7 from Rohm&Haas Co, USA), as selective sorbent for the ferric species, and a weak cation resin with carboxylate functionality (Purolite C106 from Purolite Co.,UK) for removal and recovery of lead species. Cl-form anion resin was eluted with real automobile battery wastewaters (pH 3; Fes= 4BV/h; influent Fe concentration: 2 mg/L) for a column throughput exceeding 200 BV (Bed Volumes) with Fe leakage steadily below 0.2 mg/L, (ten times lower the maximum allowable concentration, MAC, for discharge in closed water bodies, enforced by EU legislation). Lead species were removed and recovered on Na/H-form cation resin (pH 6; Fexh=20 BV/h; influent Pb concentration: 4 mg/L) for a column throughput exceeding 15,000 BV at average Pb leakage below 0.03 mg/L (MAC=0.2 mgPb/L). Both sorbents were regenerated by limited amounts of 1M HC1. Specifically, resin Duolite A7 was eluted with 5 BV (Freg =2BV/h), and carboxylate resin was eluted with 30BV  相似文献   

19.
离子交换树脂法纯化和回收Lyocell纤维纺丝溶剂NMMO   总被引:4,自引:0,他引:4  
采用阴、阳离子交换树脂处理Lyocell纤维纺丝凝固浴,纯化回收凝固浴中的溶剂NMMO。研究结果表明,阴离子交换树脂脱色效果好,阳离子交换树脂能去除NMMO的分解产物吗啉和甲基吗啉,用回收后的NMMO作为溶剂纺出的纤维性能良好。  相似文献   

20.
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