Chakkrit Umpuch and Songsak Sakaew

pp. 451 - 459

Abstract

Adsorption of methyl orange (MO) using a montmorillonite modified with chitosan has been investigated. The
characteristics of montmorillonite and chitosan intercalated montmorillonite (CTS/MMT) were examined by means of SEM
and BET-analysis. The effects of operating parameters such as contact time, initial solution pH, initial dye concentration, and
temperature on the adsorption of MO were also studied. The results revealed that adsorption of MO was initially rapid and
the equilibrium time was reached after 1 hr. Adsorption kinetics were best described by the pseudo-second order model. An
aqueous solution with a pH of 2.0 was favorable for the adsorption. The equilibrium data were better fitted by Langmuir
isotherm compared to the Freundlich isotherm. The adsorption of MO increased with operating temperatures indicating an
endothermic process. Reutilization of the bio-composite was feasible. These results suggested that the CTS/MMT can be
used as an adsorbent for removal of MO from aqueous solutions.