标题：Removal of chromium(VI) and zinc(II) from aqueous solution using kaolin-supported bacterial biofilms of Gram-negative E. coli and Gram-positive Staphylococcus epidermidis
摘要：AbstractIn this study, the capacity ofEscherichia coliandStaphylococcus epidermidisbiofilms supported on kaolin in the removal of Cr(VI) and Zn(II) from aqueous solution was investigated in batch assays. The effect of initial metal concentration and contact time on the removal efficiency of Cr(VI) and Zn(II) usingE. coliandS. epidermidisbiofilms supported on kaolin. Isotherm studies show that the Freundlich isotherm best describes the Zn(II) biosorption byE. coliandS. epidermidisbiofilms and Cr(VI) biosorption ontoS. epidermidisbiofilm, and Langmuir isotherm for Cr(VI) biosorption byE. colibiofilm supported on kaolin. The kinetics of Cr(VI) and Zn(II) best fits the pseudo-second order kinetic model (R2 > 0.98), which implies that chemisorption is the rate-limiting step. The adsorptive capacity of Gram-negativeE. coliis higher than the Gram-positiveS. epidermidisin the removal of Cr(VI) and Zn(II) from aqueous solution.
