Kinetics and Isotherms Studies of Safranin Adsorption onto Two Surfaces Prepared from Orange Peels

Abstract

Removal of safranin dye from aqueous solutions using two adsorbents prepared from orange peels (Orange peels powder DP-OP and hot activated carbon HAC-OP) has been investigated under different experimental conditions. The effect of pH, contact time, adsorbent mass, and initial concentration of studied dye on the adsorption process has been studied using batch experiments procedure. The concentration of remaining dye in the solution has been estimated by means of UV-VIS molecular absorption spectrometry. The highest removal of safranin has been achieved at pH (8-9) with a maximum removal efficiency of (96 and 97%) of dye after (30 and 50 min) of agitation time for DP-OP and HAC-OP, respectively. Freundlich isotherm model represents the best fit for the experimental data; whereas the highest adsorption capacities were 55.5 mg g-1 and 1.24 mg g-1 for DP-OP and HAC-OP, respectively. The pseudo-second-order rate equation fitted well kinetic profiles for both adsorbents.