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On the removal of Mn2+ ions by adsorption onto natural and activated Chilean zeolites / Silvio Roberto Taffarel in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 336–343 Titre : On the removal of Mn2+ ions by adsorption onto natural and activated Chilean zeolites Type de document : texte imprimé Auteurs : Silvio Roberto Taffarel, Auteur ; Jorge Rubio, Auteur Année de publication : 2009 Article en page(s) : pp. 336–343 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Zeolite  Metal  ions  Ion-exchange  Langmuir  isotherms  Water  treatment Résumé : This paper describes studies of preparation, activation and physical characterization of a Chilean zeolite (Ch-zeolite) employed as adsorbent for manganese ions from aqueous solutions. The zeolite sample, composed mainly of clinoptilolite and mordenite, had a specific surface area of 118 m2 g−1 (N2 adsorption), the particles were negatively charged in a wide pH range and presented a cation-exchange capacity of 1.09 meq View the MathML source. The medium pH influenced significantly the Mn2+ ions adsorption capacity and best results were obtained at pH 6–6.8. The adsorption onto the activated zeolite followed the pseudo-second-order kinetic model and activation of the Ch-zeolite with NaOH resulted in the highest reaction rate. The equilibrium data showed excellent correlation with the Langmuir isotherm model. Ch-zeolite modification by treating it with NaCl (0.77 meq Mn2+ g−1), NaOH (0.76 meq Mn2+ g−1), Na2CO3 (0.72 meq Mn2+ g−1) and NH4Cl (0.67 meq Mn2+ g−1) increased its uptake ability when compared with the natural Ch-zeolite (0.26 meq Mn2+ g−1). These data contribute to the understanding of mechanisms involved in zeolite activation and provide some practical clues to improve the adsorption efficiency (uptake capacity and kinetics) of manganese ions. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002379 [article] On the removal of Mn2+ ions by adsorption onto natural and activated Chilean zeolites [texte imprimé] / Silvio Roberto Taffarel, Auteur ; Jorge Rubio, Auteur . - 2009 . - pp. 336–343. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 336–343 Mots-clés : Zeolite  Metal  ions  Ion-exchange  Langmuir  isotherms  Water  treatment Résumé : This paper describes studies of preparation, activation and physical characterization of a Chilean zeolite (Ch-zeolite) employed as adsorbent for manganese ions from aqueous solutions. The zeolite sample, composed mainly of clinoptilolite and mordenite, had a specific surface area of 118 m2 g−1 (N2 adsorption), the particles were negatively charged in a wide pH range and presented a cation-exchange capacity of 1.09 meq View the MathML source. The medium pH influenced significantly the Mn2+ ions adsorption capacity and best results were obtained at pH 6–6.8. The adsorption onto the activated zeolite followed the pseudo-second-order kinetic model and activation of the Ch-zeolite with NaOH resulted in the highest reaction rate. The equilibrium data showed excellent correlation with the Langmuir isotherm model. Ch-zeolite modification by treating it with NaCl (0.77 meq Mn2+ g−1), NaOH (0.76 meq Mn2+ g−1), Na2CO3 (0.72 meq Mn2+ g−1) and NH4Cl (0.67 meq Mn2+ g−1) increased its uptake ability when compared with the natural Ch-zeolite (0.26 meq Mn2+ g−1). These data contribute to the understanding of mechanisms involved in zeolite activation and provide some practical clues to improve the adsorption efficiency (uptake capacity and kinetics) of manganese ions. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002379