Journal of Colloid and Interface Science, Vol.323, No.1, 26-32, 2008
A comparative metal ion adsorption study by trimesic acid coated alumina: A potent adsorbent
Benzene-1,3,5-tri-carboxylic acid (trimesic acid, TMA) coated on basic alumina has been shown to be an effective adsorbent for Fe(III) and Fe(II) from aqueous solution. A comparative study on the adsorption of Fe(III) and Fe(II) revealed that TMA coated alumina is more selective towards Fe(III) than Fe(II). The maximum adsorptions of Fe(III) and Fe(II) were 26.6 mg/g and 8.4 mg/g, respectively. Fe(III)/Fe(II) adsorption was also compared in some cases with adsorption of Co(II) and Ni(II). Maximum uptakes (Q(m)) for Co(II) and Ni(II) were found much lower (similar to 1 mg/g) than Fe(III)/Fe(II). pH dependent studies have revealed that Fe(III) was adsorbed efficiently at high acidic condition (pH similar to 1.5) compared to Fe(II), Co(II) and Ni(II), while temperature did not have significant effect on the adsorption processes. Adsorption of Fe(III) and Fe(II) was quite rapid and thermodynamically favourable. Adsorption processes fitted well in Langmuir isotherm model and followed second order rate kinetics in all cases. (C) 2008 Elsevier Inc. All rights reserved.
Keywords:trimesic acid;basic alumina;adsorption specificity;adsorption isotherm kinetics;competitive iron removal