Adsorption of Cadmium Ions using activated carbon prepared from Coconut shell

Olowoyo, D.N   and Garuba, A.O

¹The department of industrial safety and environmental technology

²Petroleum training institute, Effurun - Warri, Delta state, Nigeria

Corresponding author Email: olowoyoniyi@yahoo.com

Accepted 12 August 2012

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.

Keywords: Cadmium ion, activated carbon and Coconut shell