Title
Removal of Cr (VI) from aqueous solution using graft copolymer of cellulose extracted from sisal fibre with acrylic acid monomer
Authors
T. HAJEETH P. N. SUDHA and K. VIJAYALAKSHMI

Received March 31, 2014
Published Volume 49 Issue 9-10 October-December
Keywords grafting, cellulose, sisal fiber, acrylic acid, adsorption isotherm

Abstract
The extraction of cellulose from sisal fiber was done initially using the steam explosion method. Extracted cellulose was grafted with acrylic acid in the presence of ceric ammonium nitrate redox initiator. The grafting phenomenon taking place between cellulose and the acrylic acid was proved by Fourier transform infrared spectroscopy (FTIR). The prepared graft copolymer was used as adsorbent for the removal of Cr (VI) from the aqueous solution. The effect of pH, contact time, and initial adsorbent dosage on the metal ion adsorption capacity was investigated. From the observed results, it was evident that the adsorption of metal ions increased with the increase in contact time and adsorbent dosage. The optimum pH was found to be 5.0 for the removal of Cr (VI) for cellulose-g-acrylic acid copolymer. The experimental data were fitted well to the Freundlich adsorption isotherm for cellulose graft acrylic acid. The correlation coefficient values of cellulose grafted acrylic acid (R2=0.99) in the Freundlich isotherm were higher than the Langmuir isotherm correlation values (R2=0.77). The pseudo second order model was found to explain the kinetics of Cr (VI) adsorption most effectively with good correlations.From the results obtained, it was concluded that the cellulose graft acrylic acid copolymer isan efficient adsorbent for the removal ofCr (VI) under optimum conditions.