Abstract

Equilibrium and Kinetic Modelling of Methyl Orange Adsorption from Aqueous Solution using Rice Husk and Egussi Peeling

Author(s): D. R. Tchuifon, S. G. Anagho, E. Njanja, J. N. Ghogomu, N. G. Ndifor-Angwafor and T. Kamgaing

The removal of methyl orange from aqueous solution by egussi peeling and rice husk was studied in a batch mode at room temperature. The study highlighted several parameters, such as the contact time, the mass of the adsorbent, the pH of the solution, and the initial concentration of the dye. The results showed that the removal of dyes by the bioadsorbents depended on the pH and the initial concentration of the sorbate. The adsorption capacity increased with increasing methyl orange concentration and the mass of the bioadsorbent. It was also established that maximum adsorption took place at pH = 2 for the two adsorbents. Using adsorbent masses of 1.3 g and initial concentration of 35 mg/L, the percentage removal of 69.45 and 70.31 were recorded for egussi peeling and rice husk, respectively. In order to deduce the adsorption mechanism, three simplified kinetic models were investigated. The kinetic study data were well represented by the pseudo second order kinetic model giving correlation coefficients (R2 ) values of 0.990 for rice husk and 0.992 for egussi peeling suggesting that chemisorption was the rate determining step. An equilibrium sudy of the adsorption process also showed that the Langmuir model best described the adsorption on egussi peeling, while Freundlich desribed that on rice husk. These results indicate that rice husk and egussi peeling have a high potential as adsorbents for removing methyl orange from aqueous solutions