Gold sorption on weak base anion exchangers with aminoguanidyl groups

Two resins with different matrices, both bearing aminoguanidyl ligands, were obtained and used for gold sorption from hydrochloric acidic and from alkali solutions. Resin 1 was a aminoguanidine derivative of poly(acrylonitril-co-vinyl acetat-co-divinyl benzene) terpolymer (AN/VA/DVB), (67:27:10 wt.%), and Resin 2 the same derivative of gel expanded poly(vinylbenzyl chloride-co-divinylbenzene) copolymer (VBC/DVB). The resins sorption capacity and sorption isotherms of both resins were determined for AuCl₄⁻ and Au(CN)₂⁻ anions. Resin 2 revealed the best sorption of gold from acidic and alkali solutions: 68 and 23 mg/g, respectively. The effect of the HCl concentration on AuCl₄⁻ removal from solution was investigated. Gold was recovered quantitatively from both resins using a 5% thiourea solution in 0.1 HCl. Both resins remained ability of multiple gold sorption and desorption under acidic conditions.     

Sorption of Sc(III) on phosphorus-containing cation exchangers

Kinetics of Sc(III) sorption from hydrochloric acid solutions on KRF-20t-60 cation exchanger is studied. The experimental data are analyzed in terms of the gel and film kinetic models. The Sc(III) diffusion coefficient in the resin phase is estimated. Static and dynamic sorption data are obtained on Sc(III) sorption from various process solutions on KRF-20t-60, PA-1, AFI-22 ion exchangers, and also on ion exchangers supported on polyacrylonitrile-based fibrous material. Desorption of Sc(III) from KRF-20t-60 is also studied.     

Sorption of cobalt by ion-exchange resins from aqueous organic solutions of mineral acids

Conclusions The sorption of cobalt on the ion-exchange resins KU-2 and AV-17 from aqueous alcohol and aqueous acetone solutions of perchloric, sulfuric, nitric, and hydrochloric acids was studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1955–1959, September, 1970.     

Selective sorption of protactinium on aminopolystyrene azo derivative chelating resins

The sorption of protactinium on chelating resins, containing arsono groups, or other salt-forming groups on an aminopolystyrene lattice, is discussed. The chelating resins were synthesized by coupling diazotizedp-aminopolystyrene witho-hydroxyphenylarsonic acid, 2-arsonobenzene-(1-azo-2)-1,8-dihydroxynaphthalene-3,6-disulphonic acid (Arsenazo I) and some other monoazo derivatives of chromotropic acid. The dependence of sorption of Pa, Zr, Nb and Ta was investigated from hydrochloric acid and sulphuric acid solutions under static conditions as a function of the concentration of the acid. The feasibility of separating Pa from Fe, U, Zr, Nb, Th and Po is shown, using a solution 10N in respect to sulphuric acid and 0.3M in respect to oxalic acid and employing a resin obtained by coupling diazotized aminopolystyrene with Arsenazo I.     

Sorption Purification of Scandium(III) To Remove Zirconium(IV) Impurity in Hydrochloric Acid Solutions

A study was made on separation of the Zr(IV) impurity from scandium(III) in hydrochloric acid solutions by sorption with KRF-20t-60 cation exchanger, including sorption kinetics and sorption under dynamic conditions. The sorbent regeneration with 5% ammonium fluoride or 10% potassium carbonate at 22°C was considered.     

Preparation and properties of macroreticular resins containing thiazole and thiazoline groups

Three macroreticular polystyrene-based resins with amino- or imino-thiazole and thiazoline groups as the functional groups have been prepared. The resins are highly stable in acid and alkaline solutions and have high selectivity for mercury(II). In the presence of hydrochloric acid, sorption of mercury attains equilibrium fairly rapidly, the time for 50% uptake of mercury being 3-6 min. There are practically no interferences. In a column operation, mercury is quantitatively recovered by elution with 0.1M hydrochloric acid containing 5% thiourea. The thiazoline resin column can be used to concentrate mercury from sea-water.     

The sorption of molybdenum(VI) by ionites from solutions in hydrochloric acid

The sorption of molybdenum(VI) by KU-2 × 8 and AV-17 × 8 ionites from solutions in hydrochloric acid (1 × 10⁻⁵−6 N) was studied. Changes in the sorption of molybdenum(VI) by cationite and anionite were observed. The isoelectric point of molybdenum in solutions in hydrochloric acid was determined from sorption and electrical migration measurements.     

Removal of iodide from aqueous solutions by polyethylenimine-epichlorohydrin resins

The iodide removal from aqueous solutions (initial I^?-concentration: 300–5,000 mg/L) by a low and a high molecular weight polyethylenimine-epichlorohydrin resin was investigated both in absence and presence of background electrolytes (NaCl and Na₂SO₄, ionic strength due to background electrolyte 0.1 M) using a batch technique, ¹³¹I as radioactive tracer and high-resolution γ-ray spectrometry. The experiments in absence of background electrolyte were performed using solutions of initial pH 3 and 7, whereas those in presence using solutions of initial pH 3. The results, which demonstrated the high iodide-removal efficiency of both resins, were modeled using the Langmuir and Freundlich isotherm equations. The experimental data were better reproduced using the Langmuir equation. Using this equation maximum sorption capacity values (Q _max) of 638.8 and 603.3 mg/g were obtained for the high molecular weight resin from solutions of initial pH 3 and 7 respectively, whereas the corresponding values for the low molecular weight one were slightly lower (552.4 and 507.5 mg/g respectively). The iodide uptake by the resins strongly depended on the presence of competing anions and especially of sulfates. The examination of sections of the I-loaded resins grains by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) revealed that iodine was evenly distributed throughout the bulk of the resins and not only bound to their surface.     

Untersuchungen zur adsorptiven Anreicherung von Elementspuren an Adsorberharzen

Summary The adsorption behaviour of trace amounts of As(III), As(V), Fe(II), Hg(II), Pd(II), Pt(IV), Sb(V), Sn(II), Sn(IV) and Tl(III) from hydrochloric and hydrobromic acid solutions on Amberlite XAD-4 and XAD-7 resins by use of a chromatographic method was investigated. As expected, in certain acid concentrations, all of the elements are adsorbed partly or quantitatively. Furthermore, the adsorbability of 23 elements from sulphuric or hydrochloric acid solutions containing iodide or thiocyanate was examined. In accordance with analogous results for chloro- and bromocompounds it was found that the distribution behaviour of iodo- and thiocyanato-compounds is similar to that of corresponding solvent extraction systems. The adsorbed species of the trace compounds were estimated by comparison of the dependence of sorption rate on ligand concentration with the species distribution in the solution. The similarity of adsorbable and extractable species was discussed.

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Teil II: Fresenius Z Anal Chem (1988) 331:588     

Sorption of palladium(II) on stannous ferrocyanide

A fine-crystalline stannous ferrocyanide (SCF) has been prepared by adding tin(II) chloride to potassium hexacyanoferrate(II) solution. The material was characterized by chemical analysis, thermogravimetry, X-ray diffraction and infrared spectra. The solubility of SCF, kinetics and sorption mechanism of palladium in hydrochloric acid solutions were investigated. The palladium exchange capacity of 2.20 mM/g dry weight have been found.     

Sorption behavior of Zn(II) ions on synthesized hydroxyapatites

Calcium hydroxyapatite (CaHAP) and barium hydroxyapatite (BaHAP) have been prepared by a wet method from aqueous solutions with cation/P molar ratio of 1.67. The prepared particles were characterized using XRD, IR, TG-DTA and BET-N(2) adsorption measurements. The potential of the synthesized hydroxyapatites to remove Zn(II) from aqueous solutions was investigated in batch reactor under different experimental conditions. Both hydroxyapatites remove Zn(II) from aqueous solutions with an efficiency higher than 98% at initial pH around 6-8. The data reveal that the initial uptake was rapid and equilibrium was established in 20 and 60 min for CaHAP and BaHAP. The sorption process follows the pseudo-first-order kinetic with a rate constant (k(ads)) equals to 1.06x10(-2) and 1.91x10(-2) min(-1) for CaHAP and BaHAP, respectively. Zn(II) removal was quantitatively evaluated using Langmuir isotherm model and the monolayer sorption capacity (Q(max)) shows the values 102.04 and 36.62 mg g(-1) for CaHAP and BaHAP clarifying the high affinity of these novel sorbents for Zn(II) ions. Kinetically, the prepared apatites are feasible sorbents retain Zn(II) ions through a favorable and spontaneous sorption process. The possibility of metal recovery and regeneration of hydroxyapatites were investigated using several eluting agents include hydrochloric acids, double distilled water, calcium chloride, barium hydroxide, and copper chloride. Different desorption levels were obtained with the different adsorbents and the maximum recovery yield was achieved with copper chloride.     

Selective metal sorption on cross-linked poly(vinylpyridine) resins

The sorption behaviour of several metal ions on five kinds of poly(4- or 2-vinylpyridine) resins, cross-linked with divinylbenzene, and with different surface properties, are examined. All the resins proposed sorb some metal ions effectively in a similar manner by anion-exchange, while the sorption of metal ions by complex formation with the pyridine moiety is strongly affected by the surface properties of the resins. A macroreticular poly(4-vinylpyridine) resin shows high affinity for copper and nickel ions in acetate buffer. Sodium chloride and/or methanol added to the working solutions influence the sorption capacities for metal ions. This resin was applied to the separation of copper/cobalt and nickel/cobalt and the concentration of copper from sea-water by a column operation.     

Studies on the recovery of Pu(IV) from hydrochloric acid-oxalic acid solutions using an anion exchange method

Sorption of Pu(IV) from hydrochloric acid-oxalic acid solutions has been investigated using different anion exchangers, viz., Dowex-1X4, Amberlite XE-270 (MP) and Amberlyst A-26 (MP) for the recovery of plutonium from plutonium oxalate solutions. Distribution ratios of Pu(IV) for its sorption on these anion exchangers have been determined. The sorption of Pu(IV) from hydrochloric acid solutions decreases drastically in the presence of oxalic acid. However, addition of aluminium chloride enhances the sorption of plutonium in the presence of oxalic acid, indicating the feasibility of recovery of plutonium. Pu(IV) breakthrough capacities have been determined with a 10 ml resin bed of each of these anion exchangers at a flow rate of 60 ml per hour using a solution of Pu(IV) with the composition: 6M HCl+0.05M HNO₃+0.1M H₂C₂O₄+0.5M AlCl₃+100 mg.l^–1 Pu(IV). The 10% Pu(IV) breakthrough capacities for Dowex-1X4, Amberlite XE-270 (MP) and Amberlyst A-26 (MP) are 15.0, 8.9 and 6.2 g of Pu(IV) l^–1 of resin respectively.     

Sorption and separation of some elements of nuclear importance using Chelex-100

Chelex-100, in the anionic form has been studied for its ability to perform selective separation and concentration of some metal ions of nuclear importance from mineral acid solutions. The sorption behavior of Zr(IV)–Nb(V), Mo(VI), Tc(VII), Te(IV) and U(VI) from solutions of hydrochloric and sulphuric acids on Chelex-100 has been studied under static and dynamic conditions. Mo(VI) and Tc(VII) have been concentrated on the resin from hydrochloric or sulphuric acid solutions at low acidities probably, as the anions MoO ₄ ^2– and TcO ₄ ^– , respectively. Te(IV) has been isolated from hydrochloric acid solutions of normalities 6 in the form of the anionic chloro complex TeCl ₆ ^2– . Optimum conditions for elution and separation of Mo(VI), Tc(VII), Te(IV) and U(VI) were recommended.     

Sorption of Zn(II) and Cd(II) by chelating resins: Comparison of three resins

Ion-exchange resins, especially chelating resins are used for pre-concentration of metal ions in trace analysis as well as for radiochemical separations following neutron activation of a variety of environmental samples. As part of a systematic study of the sorption characteristics of chelating resins, sorption of Zn(II) and Cd(II) by three chelating resins were studied for various acid conditions in nitrate and chloride media. Both Zn(II) and Cd(II) showed similar behavior. Under higher acid conditions, maximum sorption occurred in 3M HCl solutions. Under low acid conditions, the sorption increased with pH. Chelex 100 gave the highest sorption among the three resins. This revised version was published online in July 2006 with corrections to the Cover Date.     

Preparation and characterization of chelating resins loaded with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol for preconcentration of rare earth elements

 Chelating resins prepared by sorption of 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (5-BrPADAP) on macroporous resins (Amberlite XAD-4 and XAD-7) were characterized. The adsorption properties (amount of chelating agent adsorbed per gram of resin, sorption kinetics, retention capacity, etc.) and the thermodynamic quantities of each adsorption process were determined. The retention of some rare earth elements (e.g. Er, Yb and Lu) on these chelating resins was studied in order to preconcentrate them for their determination by X-Ray fluorescence spectrometry. Received: 7 September 1995/Revised: 2 January 1996/Accepted: 10 January 1996     

Influence of medium polarity upon selectivity and efficiency of alkali metal cation sorption by polyether carboxylic acid resins

The influence of medium polarity upon competitive sorption of alkali-metal cations from aqueous and aqueous methanolic solutions by the polymethacrylic acid resin Amberlite CG-50, two acyclic polyether carboxylic acid resins, and six sym-(alkyl)dibenzo-16-crown-5-oxyacetic acid resins has been investigated. Addition of methanol was found to strongly depress the selective Li(+) sorption of CG-50 and one of the acyclic polyether carboxylic acid resins. Enhancement of metal ion-crown ether interactions as the percentage of methanol in the medium was increased accentuates the Na(+) sorption selectivity for the lariat ether carboxylic acid resins. The highest Na(+) sorption selectivity was obtained for sym-(alkyl)-dibenzo-16-crown-5-oxyacetic acid resins with ethyl and propyl groups in 80% methanol-20% water.     

Ion-exchange recovery of palladium(II) from multicomponent chloride solutions

Ion-exchange sorption of palladium(II) from both concentrated aqueous hydrochloric acid solution containing Fe(III), Sn(II), Zn(II), and Cu(II) and weakly acidic concentrated aqueous ammonium chloride solution containing Zn(II) and Cu(II) was studied. The Purolite S920, Purolite S924, and Purolite S984 macroporous resins with the thiourea, thiol, and polyethylenepolyamine functional groups, respectively, were used as sorbents. Strongly basic Purolite A500 anion exchanger was also tested. The desorption of palladium(II) with aqueous ammonia, hydrochloric acid, and acidified aqueous thiourea was examined.     

Low-temperature sorption-luminescence determination of platinum using silica chemically modified with dithiocarbamate groups

Application of silica chemically modified with dithiocarbamate groups (DTCS) has been proposed for the low-temperature sorption-luminescence determination of platinum. The establishment of a sorption equilibrium in the platinum(IV) and platinum(II) extraction with DTCS from hydrochloric acid solutions takes 20 and 2 min, respectively. If the duration of the phase contact is optimal, the recovery achieves 99% in the acidity range from 4 M of HCl to pH 5. The sorption of platinum(IV) and platinum(II) results in the formation of coordination compounds of platinum(II) on the surface of the adsorbent which are luminescent in ultraviolet light when frozen (77 K). A procedure has been developed for low-temperature sorption-luminescence determination of platinum with the detection limit of 0.5 ??g of platinum per 0.1 g of the adsorbent and linearity of the calibration curve to 25 ??g/0.1 g. The developed procedure has been applied to the determination of platinum in the samples of alumoplatinum catalyst.     

氨基吡啶树脂的合成及其对贵金属离子的吸附性

合成了三种氨基吡啶树脂(APR)。功能基含量3.22—3.71mmol-NH-C_5H_4N/gAPR,吸附容量614.8—665mg Au(Ⅲ)/gAPR。摩尔络合比Au(Ⅲ)/-NH-C_5H_4N=1.0,Pt(Ⅳ)/-NH-C_5H_4N=0.48。选择吸附性Pt(Ⅳ)>Au(Ⅲ)>Cd~(2+)>Zn~(2+)>Pd(Ⅱ)>Mn~(2+)、Cu(2+)、Fe~(3+).吸附的Au(Ⅲ)可用2％硫脲水溶液定量地洗脱,再生的4-APR可重复使用。氨基吡啶树脂有应用开发前景。