COMPARATIVE ANALYSIS OF SOME EXISTING KINETIC MODELS WITH PROPOSED MODELS IN THE BIOSORPTION OF THREE HEAVY METALS IN A FLOW-BATCH REACTOR USING FIVE SELECTED MICRO-ORGANISMS

Abstract

The biosorption of three heavy metal ions namely; Zn 2+ , Cu 2+ and Mn 2+ using five microorganisms namely; Bacillus circulans, Pseudomonas aeruginosa, Staphylococcus xylosus, Streptomyces rimosus and Yeast (Saccharomyces sp.) were studied. In this paper, the effectiveness of six existing and two proposed kinetic models were compared using two statistical parameters namely; linear regression coefficient of correlation (R 2 ) and average relative error (ARE%) which were employed to study the performance of each model on the biosorption of the three heavy metals by the individual biosorbents. In terms of highest values of R 2 , first proposed model accounted for 46.7%, Pseudo second-order kinetics model 40% while Elovich, Webber-Morris and second proposed kinetic models accounted for 6.7% respectively of the total results for biosorption of the three heavy metals by five selected microorganisms. But based on values of ARE%, first proposed kinetic model accounted for 93.3% while pseudo second-order kinetic model accounted for 6.7% of the results for biosorption of the three heavy metals by the five microbes. http://dx.doi.org/10.4314/njt.v35i3.29