Comparative Study of the Adsorption of Methyl Orange by Bentonite and Activated Carbon

The adsorption of methyl orange dye on activated carbon and bentonite type Algerian clay from aqueous solutions was investigated. The bentonite has been acid-activated, whereas the activated carbon was used without pretreatment. The influence of several parameters (kinetics, contact time, sorbent amount, adsorbate concentration and pH) on the adsorption capacity was evaluated and discussed. The methyl orange dye adsorption equilibrium of active carbon is lower than that of bentonite (3 h/1 h), whereas adsorption yield with active carbon is better than that of bentonite. The adsorption capacity of bentonite is lower than that of active carbon. The methyl orange dye adsorption increases with its concentration in the aqueous solutions. The Frendlich and Langmuir models provided the best fit to the experimental data with high correlation coefficient only for active carbon. The kinetic study demonstrated that methyl orange dye adsorption on bentonite was in a good accordance with the pseudo-second- order kinetic model. The results showed that bentonite-type clay gave acceptable results compared with activated carbon and is potential to be used as an economical adsorbent for the removal of methyl orange dye.