Abstract

Abia, A. A. and Igwe, J. C.

The kinetics of sorption and intraparticulate diffusivities of Zn, Cd and Pb using maize cob was studied. The amount of the metal ions adsorbed increased with time. The highest sorption rates of the three metal ions were 71% for Zn2+ , 32% for Cd2+, and 30% for Pb2+. The fractional attainment of equilibrium showed that Zn2+ reached equilibrium before Pb2+ ion and then Cd2+ ion. This study showed that the sorption of Zn2+, Cd2+ and Pb2+ ions on maize cob is particle diffusion controlled. The rate coefficients for particle diffusion were 0.07 min-1 for Zn2+, 0.053min-1 for Pb2+ and 0.081min-1 for Cd2