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Modeling of iron removal from spent passivation baths by ion exchange in fixed-bed operation / Alfredo Ortiz in Industrial & engineering chemistry research, Vol. 48 N° 15 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7448–7452 Titre : Modeling of iron removal from spent passivation baths by ion exchange in fixed-bed operation Type de document : texte imprimé Auteurs : Alfredo Ortiz, Auteur ; Iñaki Fernández-Olmo, Auteur ; Urtiaga, Ane, Auteur Année de publication : 2009 Article en page(s) : pp. 7448–7452 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Fixed-bed  Ion  exchange  Iron  separation  Chromium(III)  passivating  baths Résumé : In this work the mathematical model that describes the kinetics of the fixed-bed ion exchange iron separation from chromium(III) passivating baths is presented. Passivation is a common step in the zinc electrodeposition galvanic process. The removal of iron species from the passivation baths allows the extention of their life, thus reducing the amount of waste to be managed and the consumption of raw materials. A commercial chelating resin, Purolite S-957, containing sulfonic and phosphonic acid functional groups was employed. Equilibrium experiments, carried out under isothermal conditions at 20 °C, were correlated to the Freundlich equation, with the following parameters KF = 25 700((mg(n−1)/n L1/n)/kgdry_resin) and n = 2.45. A simple mathematical model assuming a reversible chemical reaction as the rate-controlling step has been developed to describe the fixed-bed iron removal rate in the media solutions under study. The value of the unknown parameter, the rate coefficient for the forward reaction, kd = 10 660[(mg(n−1)/n L1/n)/(kgdry_resin h)] was obtained from experimental data of iron uptake employing parameter estimation software. The proposed model offers a satisfactory description of the behavior of the iron loading curves for three different types of real passivation baths under variable feed iron concentration and loading flow rate, using only one estimated parameter. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900407c [article] Modeling of iron removal from spent passivation baths by ion exchange in fixed-bed operation [texte imprimé] / Alfredo Ortiz, Auteur ; Iñaki Fernández-Olmo, Auteur ; Urtiaga, Ane, Auteur . - 2009 . - pp. 7448–7452. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7448–7452 Mots-clés : Fixed-bed  Ion  exchange  Iron  separation  Chromium(III)  passivating  baths Résumé : In this work the mathematical model that describes the kinetics of the fixed-bed ion exchange iron separation from chromium(III) passivating baths is presented. Passivation is a common step in the zinc electrodeposition galvanic process. The removal of iron species from the passivation baths allows the extention of their life, thus reducing the amount of waste to be managed and the consumption of raw materials. A commercial chelating resin, Purolite S-957, containing sulfonic and phosphonic acid functional groups was employed. Equilibrium experiments, carried out under isothermal conditions at 20 °C, were correlated to the Freundlich equation, with the following parameters KF = 25 700((mg(n−1)/n L1/n)/kgdry_resin) and n = 2.45. A simple mathematical model assuming a reversible chemical reaction as the rate-controlling step has been developed to describe the fixed-bed iron removal rate in the media solutions under study. The value of the unknown parameter, the rate coefficient for the forward reaction, kd = 10 660[(mg(n−1)/n L1/n)/(kgdry_resin h)] was obtained from experimental data of iron uptake employing parameter estimation software. The proposed model offers a satisfactory description of the behavior of the iron loading curves for three different types of real passivation baths under variable feed iron concentration and loading flow rate, using only one estimated parameter. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900407c