Kinetic Study of Utilizing Groundnut Shell as an Adsorbent in Removing Chromium and Nickel from Dye Effluent

Aims: To determine the adsorption of nickel and chromium in dye effluents using activated carbon prepared from groundnut shell and to determine the adsorption capacity at different contact time.
Study Design: Adsorption capacity of the adsorbent.
Place and Duration of Study: Department of Chemistry Federal University of Technology, Minna, Niger State, Nigeria, between April and November 2010.
Methodology: Activated carbon was prepared from groundnut shell using two step processes with H2SO4 as an activating agent. Three different activated carbon was produced at different residual time of 5, 10 and 15 minutes which are GS/H2SO4/5 (AC1), GS/H2SO4/10 (AC2) and GS/H2SO4/15 (AC3). Chromium and nickel batch adsorption was carried out at various contact time (30 to 150 minutes).
Results: The result indicated the maximum chromium and nickel adsorption at the contact time of 120 minutes and 150 minutes which implies that increase in contact time lead to increase in the adsorption of the heavy metals. Kinetic models including pseudo first-order, pseudo second-order and Elovich model were used to study the adsorption processes. Chromium and nickel adsorption could be best described by the pseudo second-order kinetic model.
Conclusion: The study revealed that groundnut shell, a low cost adsorbent can be effectively used as a raw material for the preparation of activated carbon for the adsorption of chromium and nickel from dye effluent.