Orthophosphate and metaphosphate ion removal from aqueous solution using alum and aluminum hydroxide

Georgantas, DA; Grigoropoulou, HP

dc.contributor.author	Georgantas, DA	en
dc.contributor.author	Grigoropoulou, HP	en
dc.date.accessioned	2014-03-01T01:26:51Z
dc.date.available	2014-03-01T01:26:51Z
dc.date.issued	2007	en
dc.identifier.issn	0021-9797	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18254
dc.subject	Adsorption isotherms	en
dc.subject	Aging	en
dc.subject	Alum	en
dc.subject	Aluminum hydroxide	en
dc.subject	Coagulation	en
dc.subject	Condensed phosphates	en
dc.subject	Metaphosphate	en
dc.subject	Orthophosphate	en
dc.subject.classification	Chemistry, Physical	en
dc.subject.other	Condensed phosphates	en
dc.subject.other	Metaphosphate	en
dc.subject.other	Orthophosphate	en
dc.subject.other	Adsorption isotherms	en
dc.subject.other	Aging of materials	en
dc.subject.other	Coagulation	en
dc.subject.other	Hydrated alumina	en
dc.subject.other	pH effects	en
dc.subject.other	Removal	en
dc.subject.other	Solutions	en
dc.subject.other	Thermal effects	en
dc.subject.other	Ions	en
dc.subject.other	aluminum hydroxide	en
dc.subject.other	aluminum potassium sulfate	en
dc.subject.other	chloride	en
dc.subject.other	magnesium	en
dc.subject.other	metaphosphoric acid	en
dc.subject.other	phosphate	en
dc.subject.other	potassium	en
dc.subject.other	sodium	en
dc.subject.other	sulfate	en
dc.subject.other	unclassified drug	en
dc.subject.other	adsorption	en
dc.subject.other	aqueous solution	en
dc.subject.other	article	en
dc.subject.other	freundlich isotherm	en
dc.subject.other	isotherm	en
dc.subject.other	pH	en
dc.subject.other	priority journal	en
dc.subject.other	temperature	en
dc.subject.other	waste component removal	en
dc.subject.other	Alum Compounds	en
dc.subject.other	Aluminum Hydroxide	en
dc.subject.other	Hydrogen-Ion Concentration	en
dc.subject.other	Ions	en
dc.subject.other	Phosphates	en
dc.subject.other	Phosphorous Acids	en
dc.subject.other	Phosphorus	en
dc.subject.other	Solubility	en
dc.subject.other	Temperature	en
dc.subject.other	Water Purification	en
dc.subject.other	X-Ray Diffraction	en
dc.title	Orthophosphate and metaphosphate ion removal from aqueous solution using alum and aluminum hydroxide	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.jcis.2007.06.058	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.jcis.2007.06.058	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	The removal of orthophosphates (10(-2) kg P m(-3)), condensed phosphates (10-2 kg P m(-3)), and mixtures of both (5 x 10(-3) kg P m(-3) as orthophosphate and 5 x 10-3 kg P m-3 as metaphosphate) in aqueous solution is studied using alum and aluminum hydroxide. The effects of coagulant dose, pH, temperature, aging of aluminum hydroxide, and presence of different ions are investigated. On the basis of the experimental mental results, alum is much more efficient in phosphorus removal than aluminum hydroxide even if, in both cases, at the conditions studied, the active coagulant form is Al(OH)(3). The differences then could be due to the higher activity of the in situ formed hydroxide. Orthophosphates and metaphosphates seem to have similar behavior vs pH variation: maximum removal is achieved at pH values 5-6 in all cases. On the other hand, in the simultaneous presence of both P forms, orthophosphate, and metaphosphate ions have different affinities for the surface sites of aluminum hydroxide, since for both alum and aluminum hydroxide, orthophosphates are preferentially removed compared to metaphosphates, due probably to orientation effects and the charge per P atom. The presence of sodium, potassium, magnesium, sulfate, chloride, and magnesium, at the concentrations studied and for a pH value of 6, does not influence P removal. Temperature variation, between 25 and 60 degrees C, does not affect alum efficiency but both P forms are increasingly removed with increasing temperature, probably due to polymer Al(OH)(3) breaking, producing new surfaces for adsorption. Aging decreases sorption capacity of Al(OH)(3), while crystallites of increasing size are formed. Finally adsorption of both P forms is best described by the Freundlich isotherm [K-F = (49.1-69.1) x 10(-3) (m(3) kg(-1))(1/N), 1/N: 0.14-0.19 for T = 25-60 degrees C] and [K-F = (1.58-2.79) x 10(-3) (m(3) kg(-1))(1/N), 1/N: 2.17-2.47 for T = 25-60 degrees C] for orthophosphate and metaphosphate, respectively. (c) 2007 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.2007.06.058	en
dc.identifier.isi	ISI:000249989500010	en
dc.identifier.volume	315	en
dc.identifier.issue	1	en
dc.identifier.spage	70	en
dc.identifier.epage	79	en