Purolite S950 Research Articles

A comparison of various ion exchange resins for the removal of ferric ions from copper electrowinning electrolyte solutions Part II: Electrolytes containing antimony and bismuth

Four commercially available ion exchange resins were tested to compare their ability to remove ferric from copper electrowinning electrolytes containing antimony and bismuth. Ion exchange batch tests were performed in the initial phase of the study and indicated that all resins tested co-loaded some antimony with the ferric. The aminophosphonic resin tested was the only resin to load a significant amount of bismuth. Further investigation was performed with the sulphonated monophosphonic resin, Purolite S957. Results were inconclusive as to whether antimony would continue to load onto the resin with time or whether the antimony would eventually reach an equilibrium loading on the resin. Antimony stripping was shown to be possible using a solution containing sulphuric acid and sodium chloride, indicating that ferric ion exchange is a technically feasible process for removal of iron from copper electrowinning electrolyte solutions containing antimony and bismuth.

Application of novel complexing agent in sorption of heavy metal ions from wastewaters on ion exchangers of various types

Ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) are very effective chelating agents used in many branches of industry. However, they are characterized by low biodegradability (EDTA) and carcinogenic effect (NTA), additionally they are quite persistent in the environment. The search for a cost effective alternative to these two most frequently used chelating agents has long been an industry target. One of them is N,N-bis(carboxylmethyl)-L-glutamic acid whose tetrasodium salt known as Dissolvine GL-38. The aim of our work was to investigate Dissolvine GL-38 as a potential alternative for EDTA or NTA in effective removal of heavy metal ions from waters and wastewaters. In the presented paper there were used for the sorption of of heavy metal ions two commercially available ion exchangers: Lewatit MonoPlus MP 64 and Purolite S-920. A series of experiments was conducted to optimise the method for the Cu(II), Zn(II), Ni(II) and Cd(II) removal from industrial effluents. It was found that the sorption efficiency of the monodisperse polystyrene anion exchanger as well as the chelating ion exchanger varied depending on metal ions concentration, pH, phase contact time, agitation, temperature and properties of ion exchangers.

EQUILIBRIUM AND KINETIC STUDIES OF COPPER (II) REMOVAL ON PUROLITE S930 RESIN

The presence of heavy metals in the environment is a major concern due to their non-biodegradability, bioaccumulation tendency, persistence in nature and toxicity to many life forms. Different treatment techniques for wastewater laden with copper have been developed in recent years to decrease the amount of wastewater produced and to improve the quality of the treated effluent. All techniques have their advantages and limitations in application. One of the most used techniques to remove copper from waste water is based on ion exchange process. In this study, the Purolite S930 resin with iminodiacetic acid (IDA) functional groups was used to remove Cu (II) ions from synthetic aqueous solutions. Batch sorption experiments were performed using both forms of the resin (sodium S930-Na and hydrogen S930-H) by varying the initial solution pH (1.0 5.0), initial concentration of copper (10 300 mg/L), temperature (20 40 C) and contact time (10 minutes up to 24 hours). The practical capacity of the resin increases with the initial solution pH, temperature and concentration of copper ions. It was observed that, initially sorption increases rapidly, but after that, the rate becomes slower; the equilibrium can be considered attained after 24 hours. The equilibrium data were analysed using Freundlich, Langmuir and Dubinin Radushkevich sorption isotherm models; sorption was best fitted by the Langmuir model. The values of calculated thermodynamic parameters (.G, .H and .S) indicate that the sorption is an endothermic and spontaneous process. The sorption kinetic data were tested using the pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models; kinetic studies showed that the sorption of copper onto chelating resin followed a pseudo-second order reaction.

STUDY OF THE COPPER (II) REMOVAL FROM AQUEOUS SOLUTIONS BY CHELATING RESIN PUROLITE S930

This work examines the influence of experimental conditions on the copper (II) ions removal from aqueous solutions using chelating ion exchange resin Purolite S930. The influence of solution pH, initial metal concentration, contact time, temperature, ionic form of the resin and resin dose was studied in batch experiments. The percent of Cu (II) removal has a maximum at pH 5.0 (buffered solutions), and increases with the increasing of resin dose, of the contact time and of temperature and decreases with increasing initial concentration of solution.

Applying Artificial Neural Networks in the Modelling of Copper Recovery Process by Ionic Exchange in Aqueous Solutions

Artificial neuronal networks are widely used in different fields such as finance, medicine, engineering, geology, chemistry, physics in order to predict, classify and control the development of different processes. The paper presents experimental data on the adsorption process of copper from aqueous solutions and compares it with theoretical data obtained by mathematical modeling using artificial neural networks (ANN). The aim of the paper is to demonstrate that ANN ensure a high accuracy in the mathematical modeling of the process. We have collected experimental data by using synthetic solutions with different pH and cooper ions concentrations, which were retained on a PUROLITE S930 cationic resin. Both experimental and theoretical data obtained using ANN show the correlation between factors which influence the ionic exchange process (pH, temperature, initial copper concentration, activation energy).

Comparative adsorption isotherms and modeling of nickel and cobalt citrate complexes onto chelating resins

The sorption characteristics of nickel and cobalt-organic acid complexes on two commercial chelating resins (Purolite S930 and S950) were compared. Purolite S390 is based on an iminodiacetic funtional group and S950 is an aminophosphonic acid resin. Batch equilibrium adsorption tests of these resins were examined and compared using various metal citrate concentrations (15–2000 mg/L) and solution pH. The solution pH of complex solutions was varied by preparing metal solutions in 0.01, 0.1, 0.5 and 1.0 M of citric acid. Equilibrium adsorption data were fitted to empirical isotherm models; linear, Langmuir, Freundlich and Redlich–Peterson (R–P) equations to establish the mechanism for the uptake of the metal complexes onto the resins. Our study showed that nickel-citrate complex adsorption exhibited both monolayer and multilayer adsorption; the mechanism on both resins varying with acid concentration, whereas cobalt complex adsorption was independent of acid concentration but the mechanism of metal loading was found to be influenced by the nature of the resins.

Steric hindrance effect on adsorption of metal–organic complexes onto aminophosphonate chelating resin

Recovery of nickel and cobalt from organic acid complexes generated by bioleaching of nickel laterite ores with heterotrophic organism and their metabolites were conducted by ion-exchange. This study investigated specifically the adsorption of nickel and cobalt complexed with citrate, malate and lactate on chelating aminophosphonate Purolite S950 and the possible steric hindrance imposed by the larger bulky metal species on the resin loading capacity. Equilibrium adsorption tests of various concentrations of metal complexes were measured and analysed by fitting the experimental adsorption data to two empirical isotherm models: Langmuir and Freundlich. The distribution of nickel and cobalt speciation estimated from the stability and formation quotient constants of these metal complexes were used in examining the roles of steric hindrance in the adsorption of metal complexes on S950. Analysis of the mechanism of adsorption of these complexes suggests the size and the nature of the metal species have a significant influence on the metal uptake. In general the metal loading capacity of the resin increased as the size of the metal complexes decreased. The type and the number of anions which coordinated with the metal as ligands dictated the size of the complexes. An interesting outcome of this study, however, is the generally higher uptake of the weakly acidic lactate complex in comparison to the smaller hydrous nickel ion; thus suggesting the important roles of both physical and chemical properties of the metal species in their adsorption on resins. In general the order of the uptake of metal species on S950 is: lactate > metal ion > malate > citrate.

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.

Kinetics of platinum(II) and platinum(IV) sorption from hydrochloric acid solutions with a complexing ion exchanger containing thiourea functional groups and with a strongly basic anion exchanger

The kinetics of platinum(II) and platinum(IV) sorption from 2 M HCl with Purolite S920 complexing ion exchanger containing thiourea functional groups and Purolite A500 strongly basic anion exchanger was studied in relation to the resin granule size, stirring intensity, and temperature.

SORPTION OF COPPER (II) AND NONIONIC SURFACTANT BY ION EXCHANGERS AND ACTIVATED CARBON

Ion exchange resins, which are widely used for the removal of copper (II) ions from effluents, can also sorb nonionic surfactants entering into the wastewater with copper (II) ions simultaneously after various industrial processes. The study of equilibrium sorption of copper (II) and nonionic surfactant Lutensol AO‐10 under laboratory conditions by different types of ion exchangers and activated carbon has shown that the Purolite S950 chelating ion exchanger has the highest sorption capacity for copper (II) ions. Ion exchangers with carboxylic functional groups demonstrate the highest affinity for nonionic surfactant. Purolite C107E weak acid cation exchanger could be suitable for the cosorption of copper (II) ions and nonionic surfactant Lutensol AO‐10. Kinetic study of this ion exchange resin leads to a conclusion that the sorption of copper (II) ions was a fast process, and after 30 min the equilibrium was attained. When the concentration of copper (II) solution decreases, difference between the sorption capacity of various ion exchangers decrease. The influence of nonionic surfactant on the sorption of copper (II) is insignificant.

Radiochemical separation of 82Sr and the preparation of a sterile 82Sr/82Rb generator column

Ion-exchange chromatography using the chelating resins Purolite S950 and Chelex 100 was investigated for the radiochemical separation of 82Sr from a RbCl target. 0.25M NH4Cl solution was employed for the retention of Sr and elution of Rb, and 2M HCl for the elution of Sr. Although both resins showed very similar results, the conditions for adsorption of Sr were different. The ammonium chloride solution was directly used with Purolite S950 while it was necessary to adjust the pH between 9 and 10 with Chelex 100. Purolite S950 was, therefore, selected for routine production of 82Sr. A procedure has been introduced for the preparation of a hydrous tin dioxide as supporting material for the 82Sr/82Rb generator column. All components of the generator column were made up of stainless steel. The column was 4 cm long, 9.5 mm O.D. and 7.1 mm I.D. Using isotonic saline (0.9% NaCl) for elution of 82Rb, elution curves with different flow rates ranging from 5 to 20 ml/min were obtained. Maximum available 82Rb was eluted in the first 20 ml. The column generator provided a sterile 82Rb in isotonic saline. The breakthrough of 82Sr over 4 weeks of elution using 7 liter of saline was on average 4.5 . 10-5% (based on the first 20 ml eluate).

Comparative study of chelating ion exchange resins for metal recovery from bioleaching of nickel laterite ores

Heterotrophic fungi and their metabolic products have been used in extracting nickel and cobalt from low grade nickel lateritic ores. This study compared the potential of two commercial chelating resins based on iminodiacetate and aminophosphonate functional groups (Purolite S930 and S950) in recovering nickel and cobalt from pregnant bioleaching solutions. The sorption characteristics of these resins were examined using various metal concentrations (from 15 to 2000 mg/L), chelating agents including citric, dl-malic and lactic acids, and solution pH. The solution pH was varied by preparing metal solutions using 0.01 and 0.1 M of organic acids. Metals were recovered from loaded resins using 2 M HNO 3. To interpret the sorption behavior of the resins, the adsorption data were fitted to the Freundlich and Langmuir models. The results showed both nickel and cobalt organic complexes adsorptions were in a good agreement with the two empirical models suggesting that the adsorption mechanisms follow a combination of monolayer and multilayer. The adsorption performance of the aminophosphonate based resin (Purolite S950) was found to exceed that of the Purolite S930. Favourable adsorptions of nickel and cobalt complexes were achieved in weakly acidic solution. Purolite S950 also showed higher selectivity toward nickel and cobalt complexes compared to Purolite S930. The desorption efficiencies from Purolite S950 were about 90% for nickel and from 82% to 98% for cobalt.

Recovery of nickel and cobalt from organic acid complexes: Adsorption mechanisms of metal-organic complexes onto aminophosphonate chelating resin

This study examined the recovery of nickel and cobalt from organic acid complexes using a chelating aminophosphonate Purolite S950 resin. These metal complexes are generated by bioleaching nickel laterite ores, a commercial nickel and cobalt mineral oxide, with heterotrophic organism and their metabolites or organic acid products. Equilibrium adsorption tests were conducted as a function of Ni and Co concentrations (15–2000 mg/L), solution pH (0.01 and 0.1 M acids) and three metabolic complexing agents (citrate, malate and lactate). It was shown that the adsorption of the various Ni- and Co-complexes on Purolite were quite low, 16–18 and 5.4–9 mg/g of resin, respectively, in comparison to the smaller nickel ions and nickel sulfate. This was attributed to the bulky organic ligands which promoted crowding effect or steric hindrance. The adsorption of these complexes was further hampered by the strong affinity of the resin to H + ions under acidic conditions. Mechanisms of adsorption, as inferred from the fitted empirical Langmuir and Freundlich models, were correlated to the proposed steric hindrance and competitive adsorption effects. Nickel and cobalt elution from the resin were found be effective and were independent of the type of metal complexes and metal concentrations. This study demonstrated the relative challenges involved in recovering nickel and cobalt from bioleaching solutions.

Recovery of nickel from Orimulsion fly ash by iminodiacetic acid chelating resin

Macroporous resins containing imminodiacetic acid (IDA) groups (Lewatit TP-207, Purolite S-930 and Amberlite IRC-748) were studied under dynamic conditions for uptake of nickel ions from the sulphate solution at pH 4 deriving from preliminary acid leaching of Orimulsion fly ash and subsequent vanadium recovery and impurities removal stages. The effects of temperature and ionic medium on the Ni adsorption were investigated. The Lewatit TP-207 showed higher Ni uptake capacity in all operating conditions examined with an adsorption capacity of 1.32 mmol of Ni/g at 40 °C using the real process solution at pH 4. The extraction of Ni adsorbed on the resin was obtained using 10 wt.% H 2SO 4; the resultant concentrated solution of nickel sulphate, containing about 13 g/L of nickel, can be suitable for elettrowinning, precipitation etc.

A sorption study of Pd(II) on aminomethylphosphonic Purolite resin S-940

Many methods for the preconcentration-recovery of platinic metals are based on complexing sorbents. As platinic metals have a high tendency to form com plexes, the complex-forming sorbents are particularly useful. This study concerns the sorption of Pd(II) on aminomethylphosphonic Purolite S-940 resin. In order to establish the optimum conditions of Pd(II) sorption on S-940 resin, the influence of the following experimental conditions: solution pH, Pd(II) initial concentration and temperature were studied. The yield of Pd(II) recovery was maximum in buffer solutions of pH 3?5 and decreases with increasing initial concentration of the solution. The equilibrium distribution of Pd(II) between the two phases (sorbent and solution) is described by the Langmuir model of monomolecular layer adsorption. The thermodynamic quantities characteristic for the Pd(II) sorption process suggest an affinity of the Purolite resin S-940 for Pd(II).

Studies of the Sorption of Palladium(II) Ions from Model Chloride Systems onto an Ion Exchanger Containing Isothiourea Groups and onto Weakly Basic Anion Exchangers of Various Types

The separation and determination of precious metals in minerals, alloys and environmental samples is very difficult due to their low concentration under natural circumstances. However, despite such difficulties, there has been a rapid development of chromatographic separation methods for noble metal ions. In the present work, laboratory studies of the selective removal of palladium(II) ions from 0.1–6.0 M HCl, 0.1–0.9 M HCl/0.9–0.1 M HNO3, 1.0 M AlCl3-0.1 M HCl and 1.0 M ZnCl2-0.1 M HCl onto various types of ion exchangers have been undertaken. In this context, the applicability of the selective ion exchanger Purolite S-920 and of the weakly basic anion exchangers Amberlyst A-21, Amberlite IRA-67 and Amberlite IRA-93 were examined. The sorption of Pd(II) ions was undertaken by both dynamic and static methods. The working ion-exchange capacities as well as the weight and bed distribution coefficients were calculated from the breakthrough curves for Pd(II) ions. The selective ion exchanger Purolite S-920 ex...

Mercury Sorption from Aqueous Solution by Chelating Ion Exchange Resins, Activated Carbon and a Biosorbent

This paper discusses Hg(II) sorption from aqueous solution onto different sorbents, e.g. a wood-based granular activated carbon (WHK), two commercially available chelating ion exchange resins (Purolite S-920 containing isothiouronium functional groups and Rohm and Haas GT-73 containing thiol functional groups) and a biosorbent (Azolla filicu-loides). These sorbents were characterized using scanning electron microscopy (SEM), determination of nitrogen and amino acid content, BET surface area by N2 adsorption at 77 K, acid=base titration, ion exchange capacity and electrophoretic measurements. Samples were also characterized by energy dispersive spectroscopy and X-ray diffraction after contact and equilibration with mercury solution. These techniques were used in an attempt to elucidate the mechanisms involved in mercury sequestration. The reduction of Hg(II) to Hg(I), i.e. soluble mercuric to insoluble mercurous chloride (Hg2Cl2) on the adsorbent surface, was found to be a controlling reaction mechanism for sorption on granular activated carbon and Azolla filiculoides. Kinetic experiments showed that mercury sorption was rapid on all of the materials. Batch equilibration experiments indicated that Rohm and Haas GT-73 has the highest mercury sorption capacity. Although mercury sorption was studied at elevated concentrations similar to those encountered in industrial effluents, it is suggested that the findings would also apply to final stage water treatment. As a general rule, it was found that mercury (II) removal increased with pH.

Selective sorption of nickel and cobalt from sulphate solutions using chelating resins

Four chelating ion exchange polymeric resins were tested to remove Ni and Co from synthetic solutions simulating pressure acid leach liquor. The goal of this work was to select a commercial resin capable of extracting nickel and cobalt with high selectivity. The resins behavior regarding nickel and cobalt sorption and desorption was described and some parameters were discussed. Nickel and cobalt sorption was studied according to some experimental parameters, such as time, initial metals concentration, Ni/Co concentration ratio and pH of the aqueous solution. The nickel and cobalt sorption results evaluated in a preliminary basis were very promising. The four commercially available ion exchange polymeric resins, Dowex M4195®, Amberlite IRC748®, Ionac SR-5® and Purolite S930®, presented very peculiar features concerning selectivity and each of them seemed to be efficient on nickel and cobalt sorption under certain experimental conditions. Dowex M4195® showed the best results for nickel and cobalt selective sorption from acid liquors, since nickel and cobalt were equally recovered, in all pH range, with small influence of other elements. Even in lower pH, such as pH=1, Dowex M4195® had the best performance for nickel and cobalt sorption. Amberlite IRC 748® also presented very promising results and further testwork would appear to be worthwhile.

Kinetics of cadmium(II) sorption by an iminodiacetic ion exchanger in the presence of a nonionic surfactant

The kinetics of cadmium(II) sorption from separate solutions and from the mixtures with nonionic surfactant Lutensol AO-10 (oxyethylated alkohols) in hydrogen form of chelating iminodiacetic ion exchanger Purolite S-930 has been investigated: kinetic curves and breakthrough curves have been obtained, determining the concentration of nonionic surfactant spectrophotometrically, and that of cadmium(II) complexometrically. The kinetic coefficients ( B t ), the coefficients of the intraparticle diffusion ( D, m 2s −1), the effective kinetic coefficients of the external mass transfer (β, s −1), the overall rate constants ( k 0, s −1) and the distribution coefficients ( K d ) have been calculated. Cadmium(ll) sorption from the separate solutions and from the mixtures with AO-10 is controlled by the intraparticle diffusion at pH 5 and pH 7.6. Reducing the initial solution acidity from pH 5 to pH 7.6, the coefficients of intraparticle diffusion ( D) for cadmium(II) increase, although they decrease as the cation exchanger saturation increases. The equilibrium sorption of cadmium(II) is slightly higher at pH 7.6 than at pH 5 both without and with the surfactant. The performance of Purolite S-930 packed column with respect to cadmium(II) is better in the absence than in the presence of the surfactant: the action of AO-10 interferes with the removal of cadmium(II). The sorption of AO-10 is negligible both in the absence and in the presence of cadmium(II). Regeneration of Purolite S-930 using 0.7 M HCl for both the removal of cadmium(II) and the conversion into hydrogen form enables the 100% recovery of the sorptive capacity. The rate of the cadmium(ti) intraparticle diffusion, its negligible concentration at the breakthrough, sufficiently high equilibrium sorption and the ability to restore the sorptive capacity refer to the possibility of the hydrogen form of Purolite S-930 practical use, including the purification of plating rinse water for its recycling, preventing the environmental contamination with cadmium(II).

Novel chelating resins with aminothiophosphonate ligands

Metal chelating resins containing aminothiophosphonate ligands were synthesised from two types of starting polymers: vinylbenzyl chloride/divinylbenzene and more polar acrylonitrile/ethyl acrylate/divinylbenzene. Both polymers were first modified with amines (ethylenediamine and diethylenetriamine) and subsequently reacted with diethyl thiophosphonochloridate. The resin based on the more polar polymer, containing 2.61 mmol/g phosphorus and 5.52 mmol/g nitrogen, modified with ethylenediamine was selected as the most promising for Cd/Ni separation. Sorption studies have been performed with 10 −4 M Cd(II) and Ni(II) solutions in 0.2 M acetate buffer in the pH range 3.7–5.6. It has been found that the aminothiophosphonate resin is highly specific for Cd (log K d=4–5), whereas Ni sorption is negligible. This new resin is compared with a commercial metal chelating polymer resin, Purolite S950, containing aminomethylphosphonate ligands.