Ion Exchange Recovery Research Articles

Removal of heavy metal ions from wastewater using ion exchange resin in a batch process with kinetic isotherm

Techniques such as selective ion exchange can be used to remove traces of heavy metals. The recently created resins provided quicker sorption kinetics and a high resin capacity for metal ions such as Lead (Pb²⁺), Copper (Cu²⁺), Zinc (Zn²⁺), Cadmium (Cd²⁺), and Nickel (Ni²⁺) ions. The elimination of Pb²⁺ and Cu²⁺ ions from aqueous solutions was examined in the current work. Purolite® C100, a strong acid cation-exchange resin, was used in experimental studies. Using packed-column chromatography, the impacts of operating factors on metal ion exchange were examined. These parameters included resin dose, initial pH, residence time, and metal ion concentration with ranges of 40 - 80 gs, 3 - 12, 30 - 90 min, and 50 -150 parts per million respectively. As part of exchange research, different doses of resin are brought into contact with a fixed volume of solution containing different concentrations and pHs of Pb²⁺ and Cu²⁺ ions for different periods. An Atomic Absorption Spectrophotometer (AAS) approach was used to measure the concentrations of metal ions. Experimental data on ion exchange were evaluated using Langmuir, Freundlich, and Temkin models.The results showed that there is a clear competition between lead and copper, as it was found that there is a convergence between the removal rates for both metals under the same conditions. The ion-exchange recovery of Cu approached 94.37 %, but Pb recovery was 92.9 % with Purolite® C100 resin dose range of 40 g to 80 g in the pH range of 3 to 12.

Ion exchange recovery of rhodium from strong ammonium chloride solutions

The authors looked at the sorption of rhodium using Puromet MTS9840, Puromet MTS9841 and Puromet MTS9850 weakly basic anion exchange resins with polyamine groups and Puromet MTS9140 ion exchange resin with thiourea groups, and they found that, when HCl is partially replaced with NH4Cl as the source of chloride ions and if the overall concentration of chloride ions remains the same (i.e. 4 mol/l), the rhodium distribution coefficients tend to drop in direct proportion to the rising share of NH4Cl in the solution. When using a mixture of 1 mol/l HCl and 3 mol/l NH4Cl, the rhodium capacities of all tested ion exchange resins are 2.5 to 6 times lower than the capacities reached when using 4 mol/l HCl solutions, with the steady-state concentrations of rhodium being equal. The sorption isotherms for the NH4Cl containing solution remain arc-shaped. At the same time, the presence of NH4Cl is associated with only a slight decrease in the rhodium sorption rates when using polyamine resins, which is demon strated in the case of the MTS9840 resin. In terms of selectivity and rhodium capacity when using chloride solutions both with and without ammonium chloride, the tested ion exchange resins can be arranged as follows: MTS9841 > MTS9840 > MTS9140 > MTS9850. It was found that when rhodium is absorbed in dynamic conditions from the following solution, g/l: Rh(III) 0,2; NH4Cl 133,7 (2.5 mol/l); HCl 54,7 (1.5 mol/l); Fe(III) 5,0; Al(III) 4,2; Zn(II) 4,0; Sn(IV) 6,0, the use of the MTS9841 anion exchange resin results in a higher recovery of rhodium (up to 98%), while the residual concentration of rhodium in the solution drops 4 times (down to 0.005 g/l) as compared with the use of the MTS9840 anion exchange resin. It is shown that the process of rhodium desorption from saturated MTS9841 anion exchange resin with a acidified thiourea solution has a minimum rate of 95%. This research was funded by the Russian Science Foundation; Project No. 21-79-30029.

Separation of Lead and Copper Ions in Acidic Media Using an Ion-Exchange Resin with a Thiourea Functional Group

This research studied the selective separation of lead and copper ions in acidic solutions using Puromet MTS 9140 resin with a thiourea functional group. The effects of operation parameters, that is, resin dosage, solution pH, ion exchange time, metal concentration, and temperature, on metal ion exchange were investigated using batch-test protocols. Ion-exchange experimental data were analyzed with Langmuir, Freundlich, and Temkin models. The results demonstrate that the MTS 9140 resin has ion-exchange selectivity for copper ions over lead ions. The ion-exchange recovery of Cu exceeded 95%, while Pb coloading was under 19% with MTS 9140 resin dosage of 0.070 g/mL in the pH range of 2.5 to 4.5. The kinetic studies showed that the ion exchange process could be better described by the pseudo-second-order model for lead and copper ions. The temperature dependence indicates the endothermic nature of the ion-exchange process. The resin also showed potential application as an effective adsorbent for removing heavy metal ions in water or wastewater treatment.

Zbasic: A Purification Tag for Selective Ion-Exchange Recovery.

A positively charged protein domain, denoted Zbasic, can be used as a general purification tag for purification of recombinantly produced target proteins by cation-exchange chromatography. The Zbasic domain is constructed from the Protein A-derived Z-domain, and engineered to be highly charged, which allows selective capture on a cation exchanger at physiological pH values. Moreover, Zbasic is selective also under denaturing conditions and can be used for purification of proteins solubilized from inclusion bodies. Zbasic can then be used as a flexible linker to the cation-exchanger resin, and thereby allows solid-phase refolding of the target protein.Herein, protocols for purification of soluble Zbasic-tagged fusion proteins , as well as for integrated purification and solid-phase refolding of insoluble fusion proteins , are described. In addition, a procedure for enzymatic tag removal and recovery of native target protein is outlined.

Ion Exchange Recovery of Platinum(IV) from Hydrochloric Acid Solutions in the Presence of Silver(I)

The ion exchange sorption of the platinum(IV) chloride complexes in the presence of silver(I) chloro complexes from 2 and 4 M aqueous solutions of hydrochloric acid is studied on Purolite anion exchangers with different functional groups. The high selectivity of the investigated sorbents with respect to platinum during its recovery from individual hydrochloric acid solutions and in the presence of silver chloride complexes is determined. Since the latter are in this case virtually not sorbed in the presence of platinum(IV), they can be separated at the stage of sorption. The excellent kinetic properties of the investigated anion exchangers are revealed, allowing platinum to be eluted after its separation from silver chloro complexes in a dynamic mode.

Ion-exchange recovery of nickel(II) from rinsing water after electroless metallization in ammonia-citrate alkaline solutions

Ion-exchange recovery of nickel(II) from rinsing water after electroless metallization in ammonia-citrate alkaline solutions

Techno-economic analysis and environmental impact assessment of citric acid production through different recovery methods

Evaluating the technical feasibility and economic viability of citric acid production at the commercial scale is challenging because it depends on several factors including type of feedstock, process parameters and production routes. In this research, techno-economic and environmental impacts of citric acid production from corn are comparatively evaluated for three scenarios. In the production process Aspergillus niger is used for corn fermentation in a commercial scale of 6400 kg/h citric acid production rate. The scenarios are defined based on application of three recovery methods, including calcium precipitation, solvent extraction, and ion exchange. From three investigated scenarios, the lowest selling price of citric acid is achieved in a scenario using solvent extraction recovery method, followed by the scenario with calcium precipitation recovery method. Sensitivity analysis shows that the minimum selling price of citric acid is highly sensitive to electricity cost, by-product credit, corn supply cost, fermentor cost and wastewater treatment cost. Environmental impacts of citric acid production in three scenarios are assessed using the life cycle assessment approach. Citric acid production with ion exchange recovery method is the most environment-friendly scenario. The results of this research are useful for the development of citric acid production in commercial scale.

Hydrometallurgical methods of recovery of scandium from the wastes of various technologies

The recovery of scandium from the wastes of the production of uranium, titanium, iron–vanadium, and alumina is studied. The applied acid schemes of scandium transfer to a solution followed by ion-exchange recovery and extraction concentration of scandium ensure the precipitation of crude scandium oxides containing up to 5% Sc2O3. Scandium oxides of 99.96–99.99% purity are formed after additional refining of these crude oxides according to an extraction technology using a mixture 15% multiradical phosphine oxide or Cyanex-925 + 15% tributyl phosphate in kerosene.

Potential uranium supply from phosphoric acid: A U.S. analysis comparing solvent extraction and Ion exchange recovery

Phosphate rock contains significant amounts of uranium, although in low concentrations. Recovery of uranium as a by-product from phosphoric acid, an intermediate product produced during the recovery of phosphorus from phosphate rock, is not unprecedented. Phosphoric acid plants ceased to produce uranium as a by-product in the early 1990s with the fall of uranium prices. In the last decade, this topic has regained attention due to higher uranium prices and expected increase in demand for uranium. This study revisits the topic and estimates how much uranium might be recoverable from current phosphoric acid production in the United States and what the associated costs might be considering two different recovery processes: solvent extraction and ion exchange.Based on U.S. phosphoric acid production in 2014, 5.5 million pounds of U3O8 could have been recovered, which is more than domestic U.S. mine production in the same year (4.9 million pounds U3O8). In comparison, uranium demand from U.S. nuclear plants in the same year was 53 million pounds U3O8 of which nearly 10% could have been met by uranium from phosphoric acid production. Annualized costs for a hypothetical uranium recovery plant are US$44–61 per pound U3O8 for solvent extraction, the process used historically in the United States to recover uranium from phosphoric acid. For ion exchange, not yet proven at a commercial scale for uranium recovery, the estimated costs are US$33–54 per pound U3O8. These results suggest that it is technically possible for the United States to recover significant quantities of uranium from current phosphoric acid production. For this type of uranium production to be economically attractive on a large scale, either recovery costs must fall or uranium prices rise.

Potentiality of Alcoholic Purification of Abu-Zaabal Impure Phosphoric Acid for Selective Ion Exchange Recovery of Uranium

Potentiality of Alcoholic Purification of Abu-Zaabal Impure Phosphoric Acid for Selective Ion Exchange Recovery of Uranium

Potentiality of Alcoholic Purification of Abu-Zaabal Impure Phosphoric Acid for Selective Ion Exchange Recovery of Uranium

A suggested procedure was studied for recovering of uranium selectively from the Abu Zaabal impure phosphoric acid assaying about 46% P2O5 and about 3% iron. This procedure involves the application of an alcoholic precipitation step for most impurities by using isopropyl alcohol and cationic resin where uranium was kept in the acid phase by a prior oxidation step. After distillation of alcohol for recycling, the uranium in the purified phosphoric acid was properly reduced to U+4 and recovered via the Chinese cation exchange resin namely; amino phosphonic (D4O4). Displacing Fe+2 from the resin, washing the resin with aqueous ammonia, eluting the resin with carbonate – bicarbonate solution and precipitating uranium from the elute as UO3-2H2O.

Ion-exchange recovery of nickel(II) and cobalt(II) from sulfuric acid solutions

Sorption recovery of nickel(II) and cobalt(II) in their joint presence in sulfuric acid solutions was studied on new samples of domestic ion exchangers of CYBBER brand. It was shown that the ion exchangers under study have a high sorption capacity for ions of both nonferrous metals, depending on the structure of a sorbent and on the acidity of a contacting solution. It was found that, after Co(II) and Ni(II) ions are extracted from weak or strong sulfuric acid solutions, they can be effectively eluted from the ion exchangers under study with a 2 M hydrochloric acid solution to an extent of 85–95% (nickel) and 87–95% (cobalt).

Ion exchange recovery of rhenium from industrially relevant sulfate solutions: Single column separations and modeling

In this study, phenomena behind recovery of Re by weak anion exchangers from sulfate solutions containing Mo and As as impurities were investigated. All the metals exist as different kinds of oxyanions or, at some conditions, cations, meaning that several phenomena need to be taken into account. Batch uptake kinetics and dynamic breakthrough experiments were conducted with three commercial resins, and a model based on competitive Langmuir isotherm and an approximate diffusion equation was used to describe competitive sorption of the oxyacids. The separation systems are also discussed in relation to thermodynamic properties of the related oxyanions.The ability of the anion exchangers to adsorb Re from concentrated sulfate solutions is related to the size and degree of hydration of perrhenate anion, ReO4−. Especially high Re equilibrium capacities of the Purolite A170 and gel-type A172 resins are related to their complex amine functional group, which favors less charged and more hydrophobic anions. However, the functionality did not explain the superior Re/Mo selectivity of the A172 resin detected especially in dynamic column experiments. Diffusion coefficients of all components were remarkably low in A172, and the measured moisture content of the resin was also low. These observations lead to a conclusion that the physical structure of the A172 is so dense that Mo species can only enter near the surface of the resin particle, which is the cause to a low uptake. Both of the Purolite resins also had a good Re/As selectivity, and are well suited for recovering Re from acidic sulfate solutions not containing Mo that are common in industrial applications.

Ion exchange recovery of chromium (VI) and manganese (II) from aqueous solutions

Sorption recovery of toxic ions – chromium (VI) and manganese (II) – from aqueous solutions with different acidity (0.001–0.5M HCl) was investigated on cation and anion exchangers synthesized with long-chained cross-linking agents (LCA). The initial concentrations of Cr(VI) and Mn(II) were 1g/L and 5g/L, respectively. It was shown that the resins with LCA possess high ionic permeability due to the elasticity of polymeric skeleton. High selectivity and good kinetic properties of these sorbents allowed to achieve quantitative (∼100%) recovery and separation of manganese (II) and chromium (VI) in counter-current columns, which results in the complete purification of solutions from toxicants (below the maximum permissible limits), whereas the valuable components (chromium and manganese) can be returned back to industrial process.

Ion exchange recovery of silver from concentrated base metal-chloride solutions

Ion exchange has not been extensively studied nor industrially used for recovering small amounts of silver from concentrated base metal-chloride solutions. A novel multistep process utilizing a weak anion exchanger with polyamine functionality is proposed and its performance was investigated experimentally. Suitability of a silica based polyamine functional resin WP-1 to the task was demonstrated by comparing Ag uptake and selectivity of several ion exchange resins and adsorbents using batch equilibrium experiments. HCl was found to be the best choice for washing impurities, especially Cu, from the bed after the loading step. Tetrasodium salt of EDTA was found suitable especially for selective desorption of lead from the loaded bed, but also other impurities were scrubbed if still present after the wash. Both thiosulfate and thiourea were shown to be effective for elution of Ag from the WP-1 bed, but thiourea is preferred because of the slight affinity of thiosulfate towards the resin. Stability of the performance of the process was shown in several consecutive adsorption–elution cycles containing all the needed washing and scrubbing steps. With the developed process, 72% pure silver product was obtained. As the washing step can be designed such that no silver is lost, the recovery yield for Ag depends only on the length of the loading step, and even 100% recovery can thus be achieved for the whole process.

Simultaneous Ion Exchange Recovery and Subsequent Separation of Platinum(II, IV), Rhodium(III), and Nickel(II) from Chloride and Sulfate-Chloride Solutions

The problem of simultaneous ion-exchange recovery of platinum(II,IV), rhodium(III), and Ni(II) and their subsequent separation by means of elution was investigated with macroporous anion exchangers Purolite S985 (complex-forming resin) and Purolite A500 (strong basic resin). It was shown that sorption properties of the former sorbent compare favorably with the latter sorbent during recovery from chloride and sulfate-chloride solutions, freshly prepared or stored over three months. The composition of solutions, concentrations, acidity, and storage time were close to industrial solutions obtained at utilization of spent catalysts. A technological scheme for the separation of recovered noble metals and nickel on anion exchanger Purolite S985 by means of elution with 2 M NH4 SCN and 2 M HCl was proposed.

Ion Exchange Recovery of Palladium(II) from Acidic Solutions Using Monodisperse Lewatit SR-7

This work focuses on the sorption recovery of palladium(II) present in chloride and chloride–nitrate(V) solutions on the commercial strongly basic anion exchanger Lewatit MonoPlus SR-7. Sorption, k...

Selective recovery of germanium with N-methylglucamine functional resin from sulfate solutions

Growing demand of germanium and uncertainties in supply create a need for research into efficient separation methods. Ion exchange recovery of germanium from sulfate solutions was studied with equilibrium experiments, column experiments, and modeling. Based on screening of four commercial resins by equilibrium experiments, a bifunctional N-methylglucamine resin was selected for dynamic adsorption studies and modeling. The adsorption of germanium onto the resin depended strongly on pH. The first pKa value of germanic acid, Ge(OH)4, is 9 and its anionic dissociation products (oxoanions) were adsorbed to the nitrogen containing groups by anion exchange mechanism. The germanium species were all adsorbed to glucose sites. Other metal ions in the studied multimetal feeds decreased the Ge adsorption directly by competition, and indirectly by acting as buffers to prevent pH increase and the dissociation of germanic acid. Iron was found to have a particularly detrimental effect on the adsorption.A competitive adsorption model was used to describe the sorption equilibrium of germanic acid and its dissociation products to glucose sites and to amine groups. A transport-dispersive model with a solid film linear driving force model was employed for the dynamic modeling. Authentic and simulated feed solutions were used to study the effect of competing metals. The feed solutions contained 63–490mg/L Ge and metal sulfates so that ionic strengths were between 0.58 and 5.82mol/L. The constructed simulation model predicted the equilibrium isotherms and the breakthrough curves of germanium well.

Ion exchange recovery of gold from iodine–iodide solutions

The recovery of gold from iodine–iodide solutions using strong base anion exchange resin has been investigated. The gold iodide complex can be effectively loaded on the resin provided the resin is not heavily loaded with triiodide. The loading of triiodide is found to be extremely strong due to the dissociation of the loaded triiodide to iodide and iodine, the latter being deposited on the resin by physiosorption thereby fouling the surface. This may be potentially detrimental to the gold recovery process but can be overcome by pre-reduction to remove most of the triiodide before loading. To strip the iodine from the resin it requires a reductive elution process. A sodium chloride based eluant solution containing sulfite is found to be highly effective for the elution of both gold and iodine.

Simultaneous sorption recovery of platinum and rhodium from sulfate–chloride solutions

The present work is devoted to simultaneous ion exchange recovery of platinum(II, IV) and rhodium(III) from sulfate–chloride solutions, freshly prepared and stored over 3months, on commercial macroporous anion exchangers with different chemical structures. The sorption was carried out from solutions with 2.0; 0.1 and 0.01mol/L HCl and H2SO4. The initial concentrations of platinum and rhodium in contacting solutions were 0.05–5.0mmol/L. Sorption and kinetic properties of selected anion exchangers were investigated and the basic parameters of ion exchange capacity, recovery, distribution coefficients, separation factors, process rate, diffusion coefficients and half-exchange times were calculated. It was shown that the anion exchangers possess high sorption ability towards platinum and rhodium during their recovery from freshly prepared and stored sulfate–chloride solutions. The optimal molar ratio of hydrochloric and sulfuric acids was determined as 1:1. It was shown that freshly prepared sulfate–chloride systems have the same efficiency during simultaneous Pt/Rh recovery as chloride solutions. In case of stored systems, the sulfate–chloride solutions compare favorably with chloride ones.