Coconut Coir Dust Ion Exchange Resins for Removal of Ni2+ ion from Aqueous Solution

Abstract

The ability of coconut coir dust, a natural adsorbent made from dried coconut husk as a non conventional and low cost sorbent for the removal of Ni²⁺ from aqueous solution was examined. The adsorption capacity was found to be dependent on the contact time and initial concentration which increased along with contact time and initial ion concentration but latter decreased with 15mg/L for the three resins (coconut coir dust (CCD), carboxylated toluene resin (CTR), and sulphonated toluene resin (STR)). Maximum adsorption was obtained after a contact time of 90minutes at an initial concentration of 15mg/L. The results were analyzed by Langmuir and Flory-Huggins isotherm. The sorption process was best described by Langmuir isotherm which indicates monolayered adsorption and chemisorption. Adsorption was found to follow pseudo-second order kinetics with average rate constant of 1.3287g/mg min. Adsorbents obtained from coconut can be used as sorbent for removing metal ions from aqueous solution.

Keywords: Adsorption, coir dust, ion exchange, Ni²⁺ions, kinetics, isotherms