Anna Wołowicz

Studies of removal of palladium(II) ions from chloride solutions on weakly and strongly basic anion exchangers

Palladium and its compounds find wide application in industry as a catalytic agent in different manufacture processes. Recovery of precious metals from industrial wastes is difficult and time consuming but in spite of these disadvantages it becomes profitable. Palladium(II) ions sorption from various chloride solutions of the composition: 0.1-6.0M HCl-0.00056 M Pd(II), 1.0M ZnCl(2)-0.1M HCl-0.00056 M Pd(II), 1.0M AlCl(3)-0.1M HCl-0.00056 M Pd(II) on the weakly and strongly basic anion exchangers (Varion ATM, Varion ADM and Varion ADAM) was discussed. The sorption research of Pd(II) ions on these resins was carried out by means of static and dynamic methods. The dynamic processes were applied in order to determine the breakthrough curves of Pd(II) ions. Moreover, the working ion-exchange capacities as well as the weight and bed distribution coefficients were determined from the Pd(II) breakthrough curves. The recovery factors of Pd(II) ions (% R) depending on the phase contact time were obtained by means of static methods. The highest ion-exchange capacities for the 0.1-6.0M HCl-0.00056 M Pd(II) systems were obtained for the weakly basic ion-exchange resin Varion ADAM.

A comparative study of chelating and cationic ion exchange resins for the removal of palladium(II) complexes from acidic chloride media

The increasing demand for palladium for technological application requires the development of ion exchange chromatography. Recently ion exchange chromatography has developed largely as a result of new types of ion exchangers available on the market of which two types are widely applied. One of them are selective (chelating) and modified ion exchangers and the other one are liquid exchangers. Two types of ion exchange resins such as chelating (Lewatit TP 214, Purolite S 920) and cationic (Chelite S, Duolite GT 73) ion exchangers are used for the recovery of palladium(II) complexes from chloride media (0.1-2.0M HCl-1.0M NaCl-0.0011 M Pd(II); 0.1-2.0M HCl-2.0M NaCl-0.0011M Pd(II)). The influence of concentration of hydrochloric acid, sodium chloride as well as the phase contact time on the degree of recovery of palladium(II) complexes was studied. Moreover, the amount of palladium(II) chlorocomplexes sorbed onto ion exchangers, the working ion exchange capacities and the weight and bed distribution coefficients were calculated in order to judge which of two types of resins possesses the best performance towards palladium(II) complexes.

Selective Adsorption of Palladium(II) Complexes onto the Chelating Ion Exchange Resin Dowex M 4195 – Kinetic Studies

The chelating ion exchange resin – Dowex M 4195 was used in palladium(II) complexes adsorption from the acidic solutions. This study discusses the sorption kinetics, and more specifically the interparticle diffusion behavior of palladium(II) onto Dowex M 4195. The adsorption studies were used to determine the amount of palladium(II) complexes uptake (resin loading), the distribution coefficients, and the recovery efficiency of Pd(II) complexes. The influence of the agitation speed, the beads size (mean radius of swollen particles), the palladium concentrations, as well as acid concentrations (ionic strength of solutions), the macrocomponent addition (sodium chloride), and the phases contact time was also discussed. Moreover, the effect of temperature was taken into account during the determination of the isotherms. The experimental data obtained at 100 µg/cm3 Pd(II) initial concentration were applied to the kinetic models, and the sorption parameters as well as the normal standard deviation were calculated. Moreover, the Langmuir, Freundlich, and Tempkin‐Pyzhev isotherm models were applied and the isotherms parameters were calculated.

Sorption Behavior of Dowex PSR-2 and Dowex PSR-3 Resins of Different Structures for Metal(II) Removal

ABSTRACT The sorption behavior of palladium(II) (Pd(II)) onto strongly basic anion exchange Dowex resins was studied depending on the concentration of hydrochloric acid (0.1–6.0 M HCl–100 mg Pd(II)/L), concentration of hydrochloric and nitric(V) acids (0.1–0.9 M HCl–0.9–0.1 M HNO3–100 mg Pd(II)/L), and the time of contact of the solution with the anion exchange resin in the batch mode. Similar research was carried out also for the base metal ions such as cobalt(II) (Co(II)), copper(II) (Cu(II)), nickel(II) (Ni(II)), and zinc(II) (Zn(II)). The sorption process was also examined depending on the initial Pd(II) concentration, agitation rate, bead size distribution, and temperature. Pd(II) sorption was also checked in the column mode. The equilibrium and kinetic characteristics of the sorption of Pd(II) with the Dowex PSR-2 and Dowex PSR-3 anion exchange resins were determined. The possibilities of Pd(II) elution and reuse using the batch method was exploited. Pd(II) and Zn(II) sorption on the Dowex resins is time and concentration of acids dependent. Evaluating the determination coefficients, the kinetic studies showed that the pseudo-second-order equation and the Langmuir model described the data more appropriately than others. The maximum sorption capacity was 165.15 mg Pd(II)/g for Dowex PSR-2 and 184.39 mg Pd(II)/g for Dowex PSR-3. Dowex resins give quantitative Pd(II) removal from diluted acidic solutions.

Polyacrylate Ion Exchangers in Sorption of Noble and Base Metal Ions from Single and Tertiary Component Solutions

Two polyacrylic resins of different types such as Purolite S-984 (macroporous, chelating with a polyacrylic matrix supporting functional groups of the polyamine type) and Amberlite IRA-478RF (gel, intermediate polyacrylic anion exchanger with the tertiary amine and quaternary ammonium functional groups) were applied in removal of palladium(II) metal ions from HCl and HCl – HNO3 solutions. Its sorption behaviors for base (Co(II), Ni(II), Cu(II), Ni(II)) and other noble metal (Pt(IV), Au(III)) ions, kinetics, and equilibrium studies were carried out in detail. The obtained results indicate that the resin is characterized by high sorption capacity and good kinetics of the sorption process. For the elution, the solutions of various reagents, that is, HCl, HNO3, H2SO4, NaOH, NH4OH, (NH2)2CS were studied as regards the complete release of the metal ions retained by the resin. Gold(III) could be eluted quantitatively from the loaded resin whereas Pd(II) and Pt(IV) could not by means of the applied eluting agent.

Ion Exchange Method for Removal and Separation of Noble Metal Ions

Ion exchange has been widely applied in technology of chemical separation of noble met‐ al ions. This is associated with dissemination of methods using various ion exchange res‐ ins which are indispensable in many fields of chemical industry. Due to small amounts of noble elements in nature and constant impoverishment of their natural raw materials, of particular importance are physicochemical methods of their recovery from the second sources e.g. worn out converters of exhausted gases, chemical catalysts, dental alloys, anodic sludges from cooper and nickiel electrorefining as well as waste waters and run‐ ning off waters from refineries containing trace amount of noble metals. It should be stat‐ ed that these waste materials are usually pyroand hydrometallurgically processed. Recovery of noble metals, from such raw materials requires individual approach to each material and application of selective methods for their removal. Moreover, separation of noble metals, particularly platinum metals and gold from geological samples, industrial products, synthetic mixtures along with other elements is a problem of significant impor‐ tance nowadays. In the paper the research on the applicability of different types of ion exchangers for the separation of noble metals will be presented. The effect of the different parameters on their separation will be also discussed. The examples of the removal of no‐ ble metals chlorocomplexes will also be presented in detail.

Toxic Heavy Metal Ions and Metal-Complex Dyes Removal from Aqueous Solutions Using an Ion Exchanger and Titanium Dioxide

Maria Curie Sklodowska University, Faculty of Chemistry, Department of Inorganic Chemistry, M. Curie-Sklodowska Sq. 2, 20-031 Lublin, Poland * E-mail: annamyrta@poczta.onet.pl Abstract The aim of the study was to compare the removal efficiency of toxic heavy metal ions: chromium(VI), nickel(II) and copper(II) as well as metal-complex dyes from aqueous solution using Lewatite VPOC 1065 and AdsorbsiaTM As500. The point of zero charge (pHPZC) of both sorbents and the influence of the initial concentration on the sorption process of Ni(II), Cu(II), Cr(VI), C.I. Acid Red 183 (AR183), C.I. Reactive Blue 21 (RB21) and nickel(II) phthalocyanine-tetrasulfonic acid tetrasodium salt (NiPc-TSATSS) were studied to determine the maximum sorption capacity. Kinetic studies were also carried out for the most effective sorbent-sorbate systems. The concentration effect of both hydrochloric acid and auxiliaries on the removal yield was also taken into account. As was found, Lewatit VPOC 1065 can be successfully applied for the treatment of textile wastewaters containing metal complex dyes and heavy metal ions. The highest sorption capacity, qe = 816.1 mg/g, was found for C.I. Acid Red 183.

Comparison of ion-exchange resins for efficient cobalt(II) removal from acidic streams

ABSTRACT The ion-exchange method was applied for cobalt(II) removal from acidic streams using Lewatit MonoPlus TP 220, Purolite A 830, Lewatit SR 7, Purolite S 984, Purolite A 400 TL, Lewatit AF 5, Dowex PSR 2, and Dowex PSR 3. The effects of phase contact time, acid concentration, initial Co(II) concentration, and temperature were evaluated. The cobalt(II) desorption, ion exchanger reuse, and attenuated total reflection with the Fourier transform infrared spectroscopy, column studies were also performed. Lewatit MonoPlus TP 220 exhibits the highest sorption capacities and sorption follows the pseudo-second-order kinetics. The Freundlich model fitted the experimental data adequately. Desorption of cobalt(II) loaded is not quantitative. Sorption capacity reduction after three cycles of sorption–desorption (static method) was not observed.

Nanosized Oxides of Different Compositions as Adsorbents for Hazardous Substances Removal from Aqueous Solutions and Wastewaters

Adsorption methods are considered to be highly effective in the industrial effluents treatment technologies. Preparation of cheap and selective adsorbents with significant sorption capacity is a serious challenge for scientists. Nanosized mixed oxides have been successfully used for removal of environmental contaminations from aqueous streams. Taking into account the morphological and microstructural properties of the nanosized oxides, mechanical strength and non-toxicity in many cases, these materials are popular. The literature review concerning removal of metal ions, dyes and polymers using nanosized single and mixed oxides was made. The adsorption parameters which affect removal efficiency, i.e. concentration, phase contact time as well as equilibrium and thermodynamic aspects, were taken into account.