Adsorption of Cd2+ using chitosan-linked p-t-buthylcalix[4]arene

Abstract

This research aims to assess the use of chitosan -linked p-t-buthylcalix[4]arene as an adsorbent of Cd2+. Adsorption was done with the batch method in the variation of acidity (pH), contact time and initial concentration of Cd2+. The experimental results showed that the optimum pH of adsorption was pH 6 for the adsorbent chitosan and 8 for chitosan -linked p-t-buthylcalix[4]arene adsorbent. The optimum adsorption contact time was 240 minutes for the both adsorbent. Study of adsorption kinetics revealed that the adsorption of Cd for two adsorbents followed the kinetics model Ho, pseudo-order 2, with adsorption rate constant 1.037x10-2 and 1.777x10-2 g mg-1 min-1 respectively. Study of adsorption isotherm presented that the using chitosan adsorbent tends to follow the Langmuir isotherm, while the adsorbent chitosan- linked p-t-buthylcalix[4]arene tend to follow Freundlich isotherm. The maximum capacity of the adsorption using chitosan and chitosan- linked p-t-buthylcalix[4]arene adsorbent 30.19 and 21.67 mol/g, with the adsorption energy 41.459 and 28.627 KJ/mol respectively.