Abstract

This research work utilizes the use of a biopolymeric adsorbent, chitosan and chitosan-GLA (cross linked chitosan) for the adsorption of these metal ions. The aim and objectives is to isolate and modify a biopolymeric adsorbent for the adsorption of nickel and lead ions. The steps involved are, deproteinization, demineralization, deacetylation and cross-linking of the adsorbent with glutaraldehyde. The adsorption capacities of these adsorbents were studied under the effect of time, adsorbent dosage, pH, initial concentration and temperature. Maximum adsorption for the effect of time was at 90 m, 0.4 g for the effect of adsorbent dosage, at pH 7, maximum adsorption was reached in studying the effect of pH and 100 mg/L for the initial concentration. Langmuir and freundlich isotherm were used to reveal which isotherm best fits the data obtained. The freundlich adsorption isotherm best fits the adsorption in this research work based on the correlation coefficient values (R²) of 0.9484 and 0.8969 respectively for nickel (II) ions and 0.9959 and 0.9828 for lead (II) ions. Pseudo first order and second order adsorptions kinetics were also used to describe the adsorption kinetics, and the second order kinetics best fits the data obtained in this research work. The second order kinetics for the adsorption of nickel and lead; chitosan gave 0.9806 and 0.7519 respectively while chitosan-glutaraldehyde gave 0.9538 for nickel and 0.9464 for lead.