Sorption/desorption studies on some natural minerals for the removal of toxic organic pollutants from aqueous solution

This work explored the sorption potential of Kyanite and Pyrolusite for the removal of phenol, chlorophenol (CP) and beta-Naphthol (BN). Uptake of phenol and CP was negligible on Kyanite and Pyrolusite. BN was significantly sorbed on these two sorbents. Maximum uptakes of BN on Kyanite and Pyrolusite were observed in acidic medium. Langmuir and Freundlich isotherms confirm favorable sorption of BN on Kyanite and Pyrolusite with high sorption efficiency in acidic medium. The kinetics studies indicate that Pseudo-second-order models are better obeyed than Pseudo-first-order model. The intraparticle diffusion models show the lines were not passing through the origin. Statistical data analysis also verifies the applicability of Pseudo-second-order model. Desorption studies were carried out by a batch process. 100% BN was recovered from Pyrolusite when hexane and hexane:propanol mixture (99:1) was used as eluent. (C) 2009 Elsevier B.V. All rights reserved.