Methylene blue adsorption by chemically activated waste pork bones / Unai Iriarte-Velasco in COLORATION TECHNOLOGY, Vol. 131, N° 4 (08/2015)  

[article]  inCOLORATION TECHNOLOGY > Vol. 131, N° 4 (08/2015) . - p. 322-332 Titre : Methylene blue adsorption by chemically activated waste pork bones Type de document : texte imprimé Auteurs : Unai Iriarte-Velasco, Auteur ; Irene Sierra, Auteur ; Emilio Atilano Cepeda, Auteur ; Raquel Bravo, Auteur ; Jose Luis Ayastuy, Auteur Année de publication : 2015 Article en page(s) : p. 322-332 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Bleu de méthylène Colorants -- Adsorption Déchets organiques -- Recyclage Hydroxyapatite L'hydroxyapatite est une espèce minérale de la famille des phosphates, de formule Ca5(PO4)3(OH), usuellement écrite Ca10(PO4)6(OH)2 pour souligner le fait que la maille de la structure cristalline comprend deux molécules. L'hydroxyapatite est le membre hydroxylé du groupe apatite. L'ion OH- peut être remplacé par le fluor, le chlore ou le carbonate. L'hydroxyapatite cristallise dans le système hexagonal. La poudre d'hydroxyapatite pure est blanche. Celles que l'on trouve dans la nature peuvent cependant être de couleur marron, jaune ou verte. Index. décimale : 667.3 Teinture et impression des tissus Résumé : Bone is an inorganic template containing organic material inside which can be converted into hydroxyapatite-rich material by pyrolysis. Nowadays, there is a growing research interest in the use of hydroxyapatite, the chemical formula of which is Ca10(PO4)6(OH)2. In the present work, pork bone, an abundant biomass source and food waste, has been converted into structured porous hydroxyapatite by a three-step process including precharring under mild conditions, chemical activation, and thermal activation. The investigated activating agents were NaOH, KOH, K2CO3, H2SO4, and H3PO4. A thorough investigation of the influence of different activating protocols on the chemical and textural properties of the produced material was carried out by nitrogen adsorption–desorption at 77 K, potentiometric titrations, Fourier transform infrared, and X-ray diffraction techniques. Chemical activation with NaOH, K2CO3, and H2SO4 increased the specific surface area up to 53%. H3PO4 reduced both surface area and pore volume, and KOH showed little influence on the pore structure. The produced materials were evaluated by methylene blue adsorption tests and showed significant improvement as a result of chemical activation. As a main effect, acid treatment increased methylene blue adsorption kinetics, probably owing to an increase in micropororosity, whereas alkali activation enhanced the adsorption capacity of the resultant biochar. Note de contenu : - EXPERIMENTAL : Materials - Physicochemical characterisation - Adsorption tests - RESULTS AND DISCUSSION : Mass yield - Pore size distribution and textural properties - Physicochemical characterisation - Adsorption kinetics : intraparticle diffusion model - Equilibrium adsorption DOI : 10.1111/cote.12160 En ligne : https://onlinelibrary.wiley.com/doi/epdf/10.1111/cote.12160 Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24433 [article]

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Microcolumn adsorption studies of acid/basic dyes related to the physicochemical properties of the adsorbent / Unai Iriarte-Velasco in COLORATION TECHNOLOGY, Vol. 130, N° 1 (02/2014)  

[article]  inCOLORATION TECHNOLOGY > Vol. 130, N° 1 (02/2014) . - p. 62-72 Titre : Microcolumn adsorption studies of acid/basic dyes related to the physicochemical properties of the adsorbent Type de document : texte imprimé Auteurs : Unai Iriarte-Velasco, Auteur ; Jon I. Alvarez-Uriarte, Auteur ; María Gonzàlez-Marco, Auteur ; Juan R. Gonzàlez-Velasco, Auteur Année de publication : 2014 Article en page(s) : p. 62-72 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Absorbants et adsorbants Acides Adsorption Alizarine L'alizarine est un colorant rouge d'origine végétale, extrait de la racine de la garance des teinturiers (Rubia tinctorum L.), une plante vivace de la famille des Rubiacées, autrefois largement cultivée pour la teinture qu'elle fournissait. Bases (chimie) Bleu de méthylène Colorants acides Index. décimale : 667.3 Teinture et impression des tissus Résumé : The adsorptive removal of cationic Methylene Blue and anionic Alizarin Red S was analysed in microcolumn tests. A detailed analysis of the influence of adsorbent surface acidity/basicity, elemental composition, Brunauer–Emmett–Teller area, pore distribution, and point-of-zero-charge pH on breakthrough properties was carried out. The characteristics of the mass transfer zone were used for evaluation of column performance. Four different activated carbons with different physical and chemical properties were analysed. It was concluded that, for adsorbents containing pores smaller than 1.7 times the solute molecular radius, the interactions between surface and solute have the greatest influence on the effective usage of column uptake capacity. A column packed with adsorbent characterised by large enough pores readily removed either anionic or cationic solutes. Partial correlation analysis revealed that the adsorption of cationic dye (Methylene Blue) was more sensitive to adsorbent textural properties in comparison with anionic dye (Alizarin Red S). Maximum column capacities were 3–4 times higher for cationic Methylene Blue than for anionic Alizarin Red S, with values of 494 and 107 mg/g respectively. The higher solubility of Alizarin Red S could be responsible for its lower and more even removal efficiencies. Finally, the surface chemistry of the adsorbent affected how the operating conditions influenced the column performance, as deduced from the opposite effect of flow rate on the adsorption of Methylene Blue by each adsorbent. Note de contenu : - MATERIAL AND METHODS : Column adsorption - Adsorbates - Characterisation of activated carbons - Assessment of column performance - RESULTS AND DISCUSSION : Textural properties and surface chemistry - Effect of adsorbent physicochemical properties on column performance - Effect of solute-surface interactions - Effect of operating conditions : flow rate DOI : 10.1111/cote.12058 En ligne : https://onlinelibrary.wiley.com/doi/epdf/10.1111/cote.12058 Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=20361 [article]

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