Adsorption of humic acid on acid-activated Greek bentonite

Doulia, D; Leodopoulos, Ch; Gimouhopoulos, K; Rigas, F

dc.contributor.author	Doulia, D	en
dc.contributor.author	Leodopoulos, Ch	en
dc.contributor.author	Gimouhopoulos, K	en
dc.contributor.author	Rigas, F	en
dc.date.accessioned	2014-03-01T01:29:48Z
dc.date.available	2014-03-01T01:29:48Z
dc.date.issued	2009	en
dc.identifier.issn	0021-9797	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19346
dc.subject	Adsorption	en
dc.subject	Bentonite	en
dc.subject	Humic acid	en
dc.subject	Kinetics	en
dc.subject	SEM	en
dc.subject	Thermodynamics	en
dc.subject.classification	Chemistry, Physical	en
dc.subject.other	Acidic pH	en
dc.subject.other	Adsorbate concentration	en
dc.subject.other	Adsorbent dose	en
dc.subject.other	Adsorption efficiency	en
dc.subject.other	Aqueous solutions	en
dc.subject.other	Batch adsorption techniques	en
dc.subject.other	Concentration ranges	en
dc.subject.other	Contact time	en
dc.subject.other	Freundlich	en
dc.subject.other	High ionic strength	en
dc.subject.other	Higher efficiency	en
dc.subject.other	Humic acid	en
dc.subject.other	Intraparticle diffusion models	en
dc.subject.other	Isotherm constants	en
dc.subject.other	Isotherm data	en
dc.subject.other	Kinetic data	en
dc.subject.other	Langmuirs	en
dc.subject.other	Methylene blue adsorption	en
dc.subject.other	Pseudo-first-order	en
dc.subject.other	Scanning electron microscopes	en
dc.subject.other	Second orders	en
dc.subject.other	SEM	en
dc.subject.other	Temkin equations	en
dc.subject.other	Thermodynamic parameter	en
dc.subject.other	Adsorption	en
dc.subject.other	Bentonite	en
dc.subject.other	Biological materials	en
dc.subject.other	Dyes	en
dc.subject.other	Ionic strength	en
dc.subject.other	Isotherms	en
dc.subject.other	Organic acids	en
dc.subject.other	Rate constants	en
dc.subject.other	Scanning electron microscopy	en
dc.subject.other	Sulfuric acid	en
dc.subject.other	adsorbent	en
dc.subject.other	bentonite	en
dc.subject.other	humic acid	en
dc.subject.other	methylene blue	en
dc.subject.other	sodium chloride	en
dc.subject.other	sulfuric acid	en
dc.subject.other	adsorption kinetics	en
dc.subject.other	aqueous solution	en
dc.subject.other	article	en
dc.subject.other	concentration response	en
dc.subject.other	controlled study	en
dc.subject.other	diffusion	en
dc.subject.other	Greece	en
dc.subject.other	ionic strength	en
dc.subject.other	isotherm	en
dc.subject.other	morphology	en
dc.subject.other	pH	en
dc.subject.other	priority journal	en
dc.subject.other	scanning electron microscopy	en
dc.subject.other	temperature sensitivity	en
dc.subject.other	thermodynamics	en
dc.subject.other	waste component removal	en
dc.subject.other	Adsorption	en
dc.subject.other	Algorithms	en
dc.subject.other	Bentonite	en
dc.subject.other	Diffusion	en
dc.subject.other	Greece	en
dc.subject.other	Humic Substances	en
dc.subject.other	Hydrogen-Ion Concentration	en
dc.subject.other	Kinetics	en
dc.subject.other	Methylene Blue	en
dc.subject.other	Microscopy, Electron, Scanning	en
dc.subject.other	Models, Chemical	en
dc.subject.other	Osmolar Concentration	en
dc.subject.other	Sulfuric Acids	en
dc.subject.other	Surface Properties	en
dc.subject.other	Temperature	en
dc.subject.other	Thermodynamics	en
dc.subject.other	X-Ray Diffraction	en
dc.title	Adsorption of humic acid on acid-activated Greek bentonite	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.jcis.2009.07.028	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.jcis.2009.07.028	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	The adsorption of humic acid on bentonite from Milos Island (Greece) acid-treated with dilute H2SO4 Solutions over a concentration range between 0.25 and 13 M has been Studied. Bentonite activated with 3 M Sulfuric acid (AAS) showed a higher efficiency in removing humic acid from aqueous solutions and was selected for further investigation. The specific surface area of acid-activated bentonite was estimated using the methylene blue adsorption method. The Morphology of untreated, activated, and HA-sorbed bentonite was studied Under scanning electron microscope (SEM). The effects of contact time, adsorbate concentration, adsorbent dose, and temperature on the adsorption Of humic acid onto bentonite activated with 3 M H2SO4 were Studied using a batch adsorption technique. Acidic pH and high ionic strength proved to be favorable for the adsorption efficiency. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to describe the kinetic data and the rate constants were evaluated. The experimental isotherm data were analyzed using Langmuir, Freundlich, and Temkin equations and the isotherm constants were determined. Thermodynamic parameters (Delta H degrees, Delta S degrees, and Delta G degrees) of adsorption of humic acid onto acid-activated bentonite with 3 M Sulfuric acid were also evaluated. (C) 2009 Elsevier Inc. All rights reserved.	en
heal.publisher	ACADEMIC PRESS INC ELSEVIER SCIENCE	en
heal.journalName	Journal of Colloid and Interface Science	en
dc.identifier.doi	10.1016/j.jcis.2009.07.028	en
dc.identifier.isi	ISI:000271310200001	en
dc.identifier.volume	340	en
dc.identifier.issue	2	en
dc.identifier.spage	131	en
dc.identifier.epage	141	en