Adsorption of nickel(II) from aqueous solution onto activated carbon prepared from coirpith

Activated carbon has been prepared from coirpith by chemical activation and characterized. Carbonised coirpith is able to adsorb Ni(II) from aqueous solution. It was noted that a decreasing in the carbon concentration with constant Ni concentration, or an increase in the Ni concentration with constant carbon concentration resulted in a higher nickel uptake per unit weight of carbon. The Langmuir and Freundlich models for dynamics of metal ion uptake proposed in this work fit the experimental data reasonably well. The adsorption capacity (Q(0)) calculated from Langmuir isotherm was 62.5 mg Ni(II) g(-1) at initial pH of 5.0 at 30 degreesC for the particle size 250-500 mum. The adsorption of Ni increased with pH from 2 to 7 and remained constant upto 10. The recovery of Ni(II) after adsorption can be carried out by treatment of the Ni loaded carbon with HCL Desorption studies confirms adsorption is ion exchange. As coirpith is discarded as waste material from coir processing industries, the carbon is expected to be economical product for metal ion remediation from water and wastewater. (C) 2001 Elsevier Science B.V. All rights reserved.