Biosorptive capacity of yam peels waste for the removal of dye from aqueous solutions

Abstract

Removal of ultramarine blue dye from aqueous solution using yam peels waste was well investigated in this study. The effect of adsorbent concentration, dye concentration, time and pH were evaluated. Maximum adsorption occurred at pH of 10.There was a general increase in adsorption with increase in adsorbent concentration, dye concentration, time and temperature, respectively. The pseudo second order model with R² of 0.98, provided a better description for the adsorption process than the first order, showing that adsorption occurred mainly by  intra-particle diffusion. The Freundlich and Langmuir isotherms were found suitable for describing the adsorption.  Maximum  adsorption capacity(q_m) was obtained as 0.940(mg/g).The separation factor S_F was obtained as 0.72 is less than unity, indicating that yam peels waste adsorption of ultramarine blue dye is quite favourable.

Keywords: Ultramarine blue, Biosorption, Adsorption kinetics, Adsorption isotherms