Abstract
This paper communicates synthesis of aminopropyl functionalized aerogel by grafting 3-aminopropyltrimethoxy silane (APTMS) onto the surface of nano sol-gel silica by post synthetic grafting procedure. The physico-chemical behavior of the grafted silica is investigated by SEM, XRD, FTIR and TGA techniques. The BET surface area analysis technique is used for the determination of the surface area, total pore volume and pore diameter. The effectiveness of chromium removal was systematically monitored as a function of the pH of the medium, agitation time, Cr(III) ions concentration and functionalized silica dosage. The chromium uptake followed Freundlich, Langmuir and D-R isotherm models and sorption capacity computed from the Langmuir model is 1.67 mmol g(-1). The effect of temperature on sorption is also checked and various thermodynamic parameters like Delta H, Delta S, and Delta G are calculated and discussed. Regeneration studies show that the sorbent is reusable. The effect of interfering cations and anions is also investigated. (C) 2014 Elsevier Inc. All rights reserved.