Comparison of two-stage sorption design models for the removal of lead ions by polyvinyl-modified Kaolinite clay.

Kaolinite clay obtained from Ubulu-Ukwu, Delta State in Nigeria was modified with polyvinyl-alcohol (PVA) reagent to obtained PVA-modified Kaolinite clay. Kinetic and equilibrium data were obtained for the batch adsorption of Pb(2+) onto PVA-modified Kaolinite clay. Time-dependent Langmuir and pseudo-second order kinetic models (TDLM and PSOM) were developed to predict the optimized minimum operating time for the adsorption of Pb(2+) onto PVA-modified Kaolinite clay in a two-stage batch adsorber system. Results obtained suggest that the two-stage batch adsorber process leads to improved contact time and increased percentage Pb(2+) removal. Data from both models (TDLM and PSOM) were compared using t-test and F-test and were found to be precise enough for use in the optimization of kinetic data for a two-stage adsorption of Pb(2+) ions from aqueous solution.