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Adsorption of sodium dodecyl benzene sulfonate from aqueous solution using a modified natural zeolite with CTAB / Silvio R. Taffarel in Minerals engineering, Vol. 23 N° 10 (Septembre 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 10 (Septembre 2010) . - pp. 771–779 Titre : Adsorption of sodium dodecyl benzene sulfonate from aqueous solution using a modified natural zeolite with CTAB Type de document : texte imprimé Auteurs : Silvio R. Taffarel, Auteur ; Jorge Rubio, Auteur Année de publication : 2011 Article en page(s) : pp. 771–779 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Zeolite  Zeolite  modification  Adsorption  Sodium  dodecyl  benzene  sulfonate  Water  treatment Résumé : This paper describes studies of surface modification of a natural Chilean zeolite with cetyl trimethylammonium bromide (CTAB), to investigate the adsorption efficiency for the removal from aqueous solution of an anionic surfactant, sodium dodecyl benzene sulfonate (SDBS), at bench scale. Modification of the zeolite with CTAB (named ZMS) was based on the external cation exchange capacity (ECEC) of 0.11 meq g−1. The medium pH influences the SDBS ions adsorption rate onto ZMS and the adsorption followed the pseudo-second-order kinetic model. Equilibrium data showed excellent correlation with the Langmuir isotherm model. The adsorption capacities depended on maximum uptakes followed the CTAB concentration or coverage ranging from 40% to 660% of the ECEC. The maximum adsorption capacity of 30.7 mg SDBS g−1 was obtained at 660% of ECEC value. These data contribute for the understanding of mechanisms involved in zeolite modification and provide same practical clues to improve the adsorption efficiency (uptake capacity) of anionic surfactants. Results were discussed in terms of interfacial and solution chemistry phenomena. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001512 [article] Adsorption of sodium dodecyl benzene sulfonate from aqueous solution using a modified natural zeolite with CTAB [texte imprimé] / Silvio R. Taffarel, Auteur ; Jorge Rubio, Auteur . - 2011 . - pp. 771–779. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 10 (Septembre 2010) . - pp. 771–779 Mots-clés : Zeolite  Zeolite  modification  Adsorption  Sodium  dodecyl  benzene  sulfonate  Water  treatment Résumé : This paper describes studies of surface modification of a natural Chilean zeolite with cetyl trimethylammonium bromide (CTAB), to investigate the adsorption efficiency for the removal from aqueous solution of an anionic surfactant, sodium dodecyl benzene sulfonate (SDBS), at bench scale. Modification of the zeolite with CTAB (named ZMS) was based on the external cation exchange capacity (ECEC) of 0.11 meq g−1. The medium pH influences the SDBS ions adsorption rate onto ZMS and the adsorption followed the pseudo-second-order kinetic model. Equilibrium data showed excellent correlation with the Langmuir isotherm model. The adsorption capacities depended on maximum uptakes followed the CTAB concentration or coverage ranging from 40% to 660% of the ECEC. The maximum adsorption capacity of 30.7 mg SDBS g−1 was obtained at 660% of ECEC value. These data contribute for the understanding of mechanisms involved in zeolite modification and provide same practical clues to improve the adsorption efficiency (uptake capacity) of anionic surfactants. Results were discussed in terms of interfacial and solution chemistry phenomena. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001512

Removal of Mn2+ from aqueous solution by manganese oxide coated zeolite / Silvio R. Taffarel in Minerals engineering, Vol. 23 N° 14 (Novembre 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 14 (Novembre 2010) . - pp. 1131–1138 Titre : Removal of Mn2+ from aqueous solution by manganese oxide coated zeolite Type de document : texte imprimé Auteurs : Silvio R. Taffarel, Auteur ; Jorge Rubio, Auteur Année de publication : 2011 Article en page(s) : pp. 1131–1138 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Zeolite  Manganese  oxide  Adsorption  Metal  ions  Water  treatment Résumé : The preparation, characterization, and adsorption properties of Mn2+ by manganese oxide coated zeolite (MOCZ) and its ability in removing Mn2+ by adsorption were investigated. Characterization analyses were used to monitor the surface properties (and their changes) of the coated layer and metal adsorption sites on the surface of MOCZ. The adsorption experiments were carried out as a function of solution pH, adsorbent concentration and contact time. Binding of Mn2+ ions onto MOCZ was highly pH dependent with an increase in the extent of adsorption with the pH of the media investigated. After the Mn2+ adsorption by MOCZ, the medium pH decreased and enhanced with increasing adsorbent concentration. The pseudo-second-order model fitted better among all the kinetic models suggesting that the adsorption mechanism might be a chemisorption process. The equilibrium data showed excellent correlation for both Langmuir and Freundlich isotherm model and this implies both monolayer adsorption and a heterogeneous surface existence in MOCZ. At pH = 6, the Mn2+ uptake by MOCZ attained as high as 1.1 meq Mn2+ g−1 at equilibrium. The results suggested that MOCZ presents a fairly good potential as an adsorbent for an efficient removal of Mn2+ ions from aqueous solution. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001767 [article] Removal of Mn2+ from aqueous solution by manganese oxide coated zeolite [texte imprimé] / Silvio R. Taffarel, Auteur ; Jorge Rubio, Auteur . - 2011 . - pp. 1131–1138. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 14 (Novembre 2010) . - pp. 1131–1138 Mots-clés : Zeolite  Manganese  oxide  Adsorption  Metal  ions  Water  treatment Résumé : The preparation, characterization, and adsorption properties of Mn2+ by manganese oxide coated zeolite (MOCZ) and its ability in removing Mn2+ by adsorption were investigated. Characterization analyses were used to monitor the surface properties (and their changes) of the coated layer and metal adsorption sites on the surface of MOCZ. The adsorption experiments were carried out as a function of solution pH, adsorbent concentration and contact time. Binding of Mn2+ ions onto MOCZ was highly pH dependent with an increase in the extent of adsorption with the pH of the media investigated. After the Mn2+ adsorption by MOCZ, the medium pH decreased and enhanced with increasing adsorbent concentration. The pseudo-second-order model fitted better among all the kinetic models suggesting that the adsorption mechanism might be a chemisorption process. The equilibrium data showed excellent correlation for both Langmuir and Freundlich isotherm model and this implies both monolayer adsorption and a heterogeneous surface existence in MOCZ. At pH = 6, the Mn2+ uptake by MOCZ attained as high as 1.1 meq Mn2+ g−1 at equilibrium. The results suggested that MOCZ presents a fairly good potential as an adsorbent for an efficient removal of Mn2+ ions from aqueous solution. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510001767