Amount Of Ion Exchanger Research Articles

Novel Potentiometric Sensor for the Selective Determination of Cefotaxime Sodium and Its Application to Pharmaceutical Analysis

Cefotaxime was selectively determined using a sensor based on polymeric membrane electrode. The membrane incorporated a low-cost and commercially available anion exchanger namely tridodecyl methyl ammonium bromide (TDMAB), embedded in a plasticized PVC matrix. The influence of the composition of the membrane (e.g., type and amount of ion exchanger, besides the plasticizer type) on potentiometric behavior of the synthesized membrane electrode was investigated. The optimized membrane electrode showed near-Nernstian response towards cefotaxime with slope of −53.65 mV decade−1. The linear concentration range for the quantitation of cefotaxime sodium was 0.17 – 10 mM. The calculated detection limit was 0.12 mM. The prepared TDMAB based membrane was incorporated in a tubular-type sensor. The sensor was adopted for continuous cefotaxime determination under hydrodynamic mode. The tubular-type sensor showed a near-Nernstian response (−52.90 mV decade−1) in a range of concentrations of 0.5 – 10 mM. The selectivity studies demonstrated that the optimized membrane electrode displayed high selectivity for cefotaxime over several members of anions and other cephalosporin drugs such as; cefaclor, cefadroxil, cefoperazone, cefradine and ceftazidime. The analytical utility of suggested membrane sensor was demonstrated by cefotaxime quantification in different pharmaceutical formulations using both the direct potentiometric and flow-injection methods. The calculated results were in accordance to those obtained using the reported UV–visible method in respect to precision and accuracy.

Study Regarding the Presence of Zn(II) in Thermal Waters for Cosmetic Use

The experimental investigations aimed to determine the optimal conditions for the process of zinc removal from thermal waters with the PUROLITE S920 ion exchange resin. It was determined the residual zinc concentration dependence on the amount of ion exchanger at different initial zinc concentrations in solution and different stirring times. The optimum conditions for achieving a residual concentration below 1 mg/L are: ion exchange rate 1.6 g/L, stirring time about 45 min. The PUROLITE S920 ion exchanger can be successfully used to remove very small amounts of zinc ions from the solution.

Oxidative chemical polymerization of 3, 4‐ethylenedioxythiophene and its applications in antistatic coatings

AbstractThe oxidative chemical polymerization of 3, 4‐ethylenedioxythiophene (EDOT) was conducted at room temperature in the presence of poly(styrene sulfonate) (PSS) as the doping agent, sodium supersulphate (Na2S2O8) and ferric sulphate(Fe2(SO4)3) as the compound oxidant and deionized water as the solvent. In order to remove sodium ion (Na+), ferric ion (Fe3+), and sulfate ion (SO42−), certain amount of ion exchanger was added after 24 h, the dark blue poly(3, 4‐ethylenedioxythiophene) (PEDT)/PSS solution was obtained. The influence of different proportions of EDOT and PSS, different proportions of EDOT and the compound oxidant, different stirring rates on the morphology, and surface resistivity were discussed. The influence of pH value of the PEDT/PSS solution, the coating thickness, and soak time on the surface resistivity was investigated. Recipe and experimental conditions were optimized and the PEDT/PSS solution was obtained with excellent performance which has relatively low in surface resistance, good water tolerance, and light transmittance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Investigation of the Dissolution of Colemanite Ore in Water and Boric Acid Solutions Including Highly Acidic Ion Exchangers under Microwave Heating

The dissolution of colemanite obtained from Bandırma Boraks Corporation was investigated in boric acid solutions containing highly acidic ion exchangers in a classical and microwave energy heating environment and the results showed that superior conversions can be obtained via microwave heating. Particle size, acid concentration, reaction temperature, stirring speed, amount of ion exchanger, solid to liquid ratio, and microwave power were selected as parameters. Dissolution kinetics of colemanite was also examined and it was observed that the dissolution rate increased with decreasing particle size and solid to liquid ratio and increased with stirring speed, acid concentration, and amount of acidic ion exchanger. The relationship between conversion and system parameters was determined with nonlinear estimation by using the statistical program Statistica 7.0. The activation energies (E) for classical and microwave heating methods were found as 24.40 and 22.98 kJmol–1, respectively.

Cr(VI) transport through ceramic ion-exchange membranes for treatment of industrial wastewaters

This work is devoted to assessment of the possibility of using ceramic membranes, which contain an ion-exchange component, such as hydrated zirconium dioxide (HZD), for Cr(VI) removal from dilute solutions by electrodialysis. Transport properties of the membranes were investigated. HZD-containing membranes were found to be permeable to anions in acidic media while they demonstrate cation-exchange properties in alkaline media. Cr(VI) anion transport through HZD membranes was studied. It was shown that an increase in the amount of ion-exchanger in the membrane results in a rise in electrodialysis efficiency. The transport number of Cr(VI) species was found to range from 0.33 to 0.63 for currents below the limiting current. It was also shown that increasing the concentration of H+ or Cr(VI) ions in the solution to be purified allows higher rate of Cr(VI) ion transport through the membrane.

Ion-exchange of Pb 2+, Cu 2+, Zn 2+, Cd 2+, and Ni 2+ ions from aqueous solution by Lewatit CNP 80

Removal of trace amounts of heavy metals can be achieved by means of selective ion-exchange processes. The newly developed resins offered a high resin capacity and faster sorption kinetics for the metal ions such as Pb 2+, Cu 2+, Zn 2+, Cd 2+, and Ni 2+ ions. In the present study, the removal of Pb 2+, Cu 2+, Zn 2+, Cd 2+, and Ni 2+ ions from aqueous solutions was investigated. Experimental investigations were undertaken using the ion-exchange resin Lewatit CNP 80 (weakly acidic) and were compared with Lewatit TP 207 (weakly acidic and chelating). The optimum pH range for the ion-exchange of the above mentioned metal ions on Lewatit CNP 80 and Lewatit TP 207 were 7.0–9.0 and 4.5–5.5, respectively. The influence of pH, contact time, metal concentration and amount of ion-exchanger on the removal process was investigated. For investigations of the exchange equilibrium, different amounts of resin were contacted with a fixed volume of Pb 2+, Cu 2+, Zn 2+, Cd 2+, and Ni 2+ ion containing solution. The obtained sorption affinity sequence in the presented work was Ni 2+ > Cu 2+ > Cd 2+ > Zn 2+ > Pb 2+. The metal ion concentrations were measured by AAS methods. The distribution coefficient values for metal ions of 10 −3 M initial concentration at 0.1 mol/L ionic strength show that the Lewatit CNP 80 was more selective for Ni 2+, Cu 2+ than it was for Cd 2+, Zn 2+ and Pb 2+. Langmuir isotherm was applicable to the ion-exchange process and its contents were calculated. The uptake of metal ions by the ion-exchange resins was reversible and thus has good potential for the removal of Pb 2+, Cu 2+, Zn 2+, Cd 2+, and Ni 2+ from aqueous solutions. The amount of sorbed metal ion per gram dry were calculated as 4.1, 4.6, 4.7, 4.8, and 4.7 mequiv./g dry resin for Pb 2+, Cu 2+, Zn 2+, Cd 2+, and Ni 2+, respectively. Selectivity increased in the series: Cd 2+ > Pb 2+ > Cu 2+ > Ni 2+ > Zn 2+. The results obtained showed that Lewatit CNP 80 weakly acidic resin had shown better performance than Lewatit TP 207 resin for the removal of metals. The change of the ionic strength of the solution exerts a slight influence on the removal of Pb 2+, Cu 2+, Zn 2+, Cd 2+, and Ni 2+. The presence of low ionic strength or low concentration of NaNO 3 does not have a significant effect on the ion-exchange of these metals by the resins. We conclude that Lewatit CNP 80 can be used for the efficient removal of Pb 2+, Cu 2+, Zn 2+, Cd 2+, and Ni 2+ from aqueous solutions.

Preparation of a New Ion-Exchanger and Its Use in Metal-Impurity Removal from Zinc-blende Leaching Solution

A new ion-exchanger for heavy metal ions was prepared with straw as main raw material. The removal process of Cu2+, Cd2+, Co2+ and Ni2+ from zinc sulphate solutions (both simulated and industrial solutions) with the ion-exchanger has been investigated as function of pH of solution, amount of ion exchanger, reaction time and temperature. After the solutions had been treated, the concentrations of Cu2+, Cd2+, Co2+ and Ni2+ can be reduced from 4.27, 8.56, 0.24 and 0.18 mmol/dm3 to 0.0018, 0.0052, 0.0075 and 0.0089 mmol/dm3 respectively. The loss of zinc ion in the solution was less 1% (mass fraction) .

The use of ion-exchange resins for the recovery of valuable species from slurries of sparingly soluble solids

An example of an industrial process which recovers valuable species by shifting the solid/liquid dissociation equilibrium condition is the extraction of rare earths from low-grade kaolinite ore by percolation leaching. Valuable species can be recovered from such sparingly soluble solids which slightly dissociate to give traces of the valuable ions in solution, using ion-exchange resins in a slurry mixture. A dissociation equilibrium exists between the dissolved ions in solution and the solid ore. If the dissolved ions are removed from solution by ion-exchange, thus continually displacing the solid/liquid dissociation equilibritrin condition, further dissolution of the solid is required according to Le Chatelier's principle so as to restore the equilibrium concentration of the valuable species in solution. It is possible to recover valuable metals from sparingly soluble solids, such as metal sulphates, by contacting a slurry of the solid with an ion-exchange resin. As a result of the ion-exchange that takes place, electrolyte solutions are created which facilitate the dissolution process and hence the overall extraction process by changing the activities of the species in solution. Complete dissolution of the solid, hence complete liberation of the valuable metal species, can be achieved provided that a sufficient amount of ion-exchanger is used. The extraction of base metal sulphates was used as a case study.

The extraction of species from slurries of insoluble solids with ion-exchange resins

Insoluble solids which slightly dissociate to give traces of ions in solution can be dissolved with ion-exchangers to recover valuable species. A dissociation equilibrium exists between the dissolved ions in solution and the solid. If the dissolved ions are removed from the solution by ion-exchange, the equilibrium concentration is restored by the further dissociation of the solid. It is possible to recover metals from insoluble solids by contacting a slurry of the solid with an ion-exchange resin which adsorbs the cation, thereby continually displacing the solid/liquid dissociation equilibrium. Complete dissolution of the solid, hence complete liberation of the valuable metal species, can be achieved provided that a sufficient amount of ion exchanger is used. The selective adsorption of calcium and magnesium in dolomite was tested. Various interactions that take place in the slurry during adsorption as well as the effects of various variables, i.e. pH, size of adsorbing species, leaching rates, resins, etc. were determined. A mathematical model for the equilibrium extraction of calcium ions from dolomite was formulated and can be used for possible other applications (rare earths) in the mineral processing industry.

A New Approach for the Filtrate Regeneration System in the Wearable Artificial Kidney

In the filtrate and/or dialysate regeneration system, which is expected to miniaturize the artificial kidney, ammonium ion decomposed from urea by immobilized urease is removed competitively by ion-exchangers from coexisting cations. Since divalent cations such as Ca2+ and Mg2+ are more favorably exchanged than ammonium ion, this system needs supplementation of these cations and, thus, additional amount of ion-exchanger. To minimize these requirements, we utilized positively charged membrane to process cation-free filtrate in which urea is dialyzed. Positively charged membranes were tested in vitro to evaluate separation efficiency between urea and cations. Equilibrium adsorption of ammonium ion to ion-exchanger with or without co-existing cations demonstrates that this filtrate regeneration system can reduce the amount of ion-exchanger up to one-half to one-third of that of the conventional system. In an ex vivo experiment with a mongrel dog, blood urea nitrogen (BUN) concentration was maintained at the same level or up to 23% less than the initial value.