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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
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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
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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
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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
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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
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R. Chiarizia K. A. D'Arcy E. P. Horwitz S. D. Alexandratos A. W. Trochimczuk 《溶剂提取与离子交换》2013,31(3):519-542
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
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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
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Spiro D. Alexandratos Christopher A. Shelley E. Philip Horwitz Renato Chiarizia 《溶剂提取与离子交换》2013,31(4):951-966
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
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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
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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
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Anatoly I. Bortun Lyudmila N. Bortun Sergei A. Khainakov A. Clearfield Camino Trobajo Jose R. Garcia 《溶剂提取与离子交换》2013,31(3):649-675
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
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离子交换树脂电再生实验研究 总被引:4,自引:0,他引:4
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
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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
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