Domènech, B.; Vigués, N.; Mas, J.; Muñoz, M.; Muraviev, D.; Macanás, J. Solvent extraction and ion exchange Vol. 32, num. 3, p. 301-315 DOI: 10.1080/07366299.2013.839192 Data de publicació: 2014-04-03 Article en revista
This work reports the results obtained by the development of two types of nanocomposite membranes containing metal nanoparticles prepared by applying the Intermatrix Synthesis technique for the synthesis of silver nanoparticles in the ion-exchange matrices of sulfonated polyethersulfone-Cardo and Nafion membranes. The stability (in terms of silver nanoparticles loss) of the polymer-metal nanocomposites was evaluated by using both ultrasonic and thermostatic baths and appeared to be appropriate for their practical applications. The dual-function nanocomposites were characterized in batch tests, first, by monitoring their catalytic activity in the reduction of p-nitrophenol to p-aminophenol and second, by evaluating their antibacterial efficiency towards E. coli. The results of the catalytic tests have shown that polymer-silver nanocomposites demonstrate remarkably better activity in comparison with their polymer-palladium nanocomposite analogues. The same nanocomposites have been shown to permit the complete disinfection of E. coli containing water within a short period of time.
Casas, S.; Aladjem, C.; Cortina, J.; Larrotcha, E.; Cremades, L.V. Solvent extraction and ion exchange Vol. 30, num. 4, p. 322-332 DOI: 10.1080/07366299.2012.686849 Data de publicació: 2012-07 Article en revista
Casas, S.; Bonet, N.; Aladjem, C.; Cortina, J.; Larrotcha, E.; Cremades, L.V. Solvent extraction and ion exchange Vol. 29, num. 3, p. 488-508 DOI: 10.1080/07366299.2011.573451 Data de publicació: 2011-05 Article en revista
Valderrama, C.; Cortina, J.; Farran, A.; Martí, V.; Gamisans, X.; de las Heras, F.X.C. Solvent extraction and ion exchange Vol. 26, num. 3, p. 271-288 DOI: 10.1080/07366290802053504 Data de publicació: 2008-06 Article en revista
The work describes the sorption of an azo dye (Acid red 14) from aqueous solution onto Granular activated carbon (GAC) in order to characterize the sorption properties. Batch experiments were performed to determine loading isotherms at different pH values and evaluate the effect of the surface functional groups of the sorbent and the dye acid-base properties. The loading equilibrium data were modelled with Langmuir, Freundlich, and Redlich-Peterson isotherms. The maximum dye sorption capacity of GAC was determined as 31 g kg(-1) at neutral and basic pH values. Kinetic experiments were carried out at different pH values and Acid Red 44 (AR14) concentrations. Three theoretical models (Pseudo first, pseudosecond order reaction models, and the Elovich model) were used to describe the dye sorption kinetics. The sorption rate constants were determined by graphical analysis of the proposed models. The study showed that sorption followed a pseudo-first order reaction model although the pseudo- second order reaction model provides an acceptable description of the sorption process.
Martinez-Llado, X.; Martinez, X.; De Pablo, J.; Gimenez, F.; Ayora, C.; Martí, V.; Rovira, M. Solvent extraction and ion exchange Vol. 26, num. 3, p. 289-300 DOI: 10.1080/07366290802053637 Data de publicació: 2008-06 Article en revista
The sorption kinetics of antimony(V) on synthetic goethite is very fast compared to the sorption of other metals on goethite (e.g. arsenic and selenium) and depends on temperature, with an activation energy of 49+9 kJ . mol21 in the temperature range 15–358C. Sorption isotherms have been developed at different temperatures and ionic strength values. The results have been modelled using a Langmuir isotherm and there is not a considerable influence of neither the temperature in the range studied
(158C–358C), nor the ionic strength (between 0.001 and 0.01 mol . dm23). Sorption is
very high at pH values lower than 8, at more alkaline pH, the sorption decreases with
pH, as expected considering the Antimony(V) predominating complex in solution, Sb(OH)6
2. Triple-layer model successfully describes the data obtained by assuming a bidentate edge-sharing surface complex of antimonate on the surface of goethite.
Goralska, E.; Coll, M.T.; Fortuny, A.; Kedari, C.; Sastre, A. Solvent extraction and ion exchange Vol. 25, num. 1, p. 65-77 DOI: 10.1080/07366290601067820 Data de publicació: 2007-01 Article en revista
This paper reports the results on the further development of activated
composite membranes (ACM) containing di-2-ethyhexyl-dithiophosphoric acid (D2EHDTPA) as a carrier. The selectivity and transport properties of D2EHDTPA based ACMs towards different metal ions including bismuth and zinc appear to be interconnected with each other. It has been shown that unlike the liquid-liquid extraction of bismuth, the use of D2EHDTPA-ACM permits to recover and to concentrate bismuth from a highly saline medium without irreversible destruction of the carrier.
The difference in the rates of bismuth and zinc transport through ACMs permits their separation since the former is concentrated in the stripping solution and the latter retains in the feed compartment of the membrane cell.
The extraction of Ni(II) from 1.0 mol.dm-3 NaNO3 by 5,8-diethyl-7-hydroxydodecan-6-oxime (DEHO), the active component of LIX 63, dissolved in toluene has been studied by distribution methods. The experimental data in the form of log D = f(pH) at several DEHO concentrations treated both graphically by curve fitting methods as well as numerically by means of the LETAGROP-DISTR program, may be explained assuming the formation of the metal species indicated in Table 1.