Adsorption of Cadmium Ions using activated carbon prepared from Coconut shell

Abstract

The adsorption of cadmium ions on activated carbon prepared from coconut shells obtained from Effurun
market via Warri were carbonized and chemically activated using phosphoric acid, potassium hydroxide,
calcium carbonate and zinc chloride solutions as activating reagents. The effects of contact time and pH in
the presence of activating reagents mentioned above on the adsorption capacity of the adsorbents were
investigated. However, the adsorption of Cd (11) ions with respect to time in all the activating agents had
similar patterns and the order of decreasing in percentage of Cd (11) ions removed according to activating
agents used is H3PO4 > ZnCl2 > KOH > CaCO3 while the results of pH indicated that adsorption of cadmium
(11) ions increased at a steady rate as the pH increased most especially in CaCO3 and KOH activating agent
solutions which is almost tending to 100% out of the four activating agents investigated. In a nutshell, the
activated carbons with high adsorption capacities can be produced from coconut shells when they are
activated with some reagents like CaCO3, KOH, H3PO4 and ZnCl2. This was attested when the influence of
equilibration time and pH on the adsorption capacities of the activated coconut shell were investigated.