STUDIES ON THE ADSORPTION OF TARTRAZINE AND SUNSET YELLOW DYES FROM AQUEOUS SOLUTION USING ACTIVATED GBAFILO (Chrysobalanus icaco) SHELL

Abstract

The potential of activated Chrysobalanus icaco shell for the removal of anionic dyes: tartrazine and sunset yellow from aqueous solution by batch adsorption experiment was investigated in this study. The adsorption capacity of the adsorbent was determined through consideration of the effects of pH, adsorbent dose, temperature, contact time and initial dye concentration. The results showed that the optimum adsorption for removal of tartrazine dye occurred at pH 1.0 while that of sunset yellow dye was at pH 2 and that adsorption equilibrium was attained within 120 min. The adsorption capacity of the adsorbent was found to increase with increase in initial concentration of the dyes and with values for tartrazine ranging from 5.97 mg/g to 23.40 mg/g and that of sunset yellow from 4.05 mg/g to 19.65 mg/g. The equilibrium adsorption of the dyes was analyzed by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models and the correlation coefficients (R2values) obtained showed that the Freundlich isotherm (R2 = 0.896) provided the best description for tartrazine dye adsorption while that of Sunset Yellow dye was best described by Dubinin-Radushkevich isotherm with R2value obtained as 0.984. The kinetic data of the tartrazine and sunset yellow dyes adsorption were best interpreted by Pseudo second-order kineticKeywords: Adsorption Isotherm, adsorption kinetics, Chrysobalanus icaco, sunset yellow dye, tartrazine dye