Adsorption of Cd(II) ions from aqueous solution using fruits peel as cost effective adsorbents

Abstract

The adsorption of cadmium ion onto different fruits peel i.e lemon, orange and banana has been investigated by batch adsorption process with the variation in the pH, metal ion concentration, adsorbent dose and contact time. The results showed maximum removal efficiency of 94.7%, 98.4%, and 83.6% for banana, lemon and orange respectively. Freundlich and Langmuir adsorption isotherm models have been applied. Langmuir adsorption isotherm model is best fitted in the adsorption showing monolayer adsorption of Cd(II) ion. Pseudo first order and second order kinetics were applied showing higher r2 values for second order kinetics. Pseudo-first order rate constant (k1) for lemon, banana and orange are 0.1384, 0.1387, and 0.1451 whereas Pseudo-second order rate constant (k2) for lemon, banana and orange are 0.857, 0.808 and 0.738 respectively.