Equilibrium and kinetic adsorption of bacteria on alluvial sand and surface thermodynamic interpretation

Abstract

Equilibrium and kinetic adsorption of Echerichia coli HB 101, E. coli JM 109, Pseudomonas fluorescens, Pseudomonas putida and Pseudomonas sp. on alluvial sand from the Canadian River alluvium (Norman, OK) was investigated through column experiments. Equilibrium adsorption of these five bacterial strains followed the Freundlich expression and was a function of zero energy points, an indication of the zero energy buffer zone. Among the microorganisms studied, P. putida had the greatest equilibrium adsorption (162.4×10 8 cell/g sediment with a microbial injectate concentration of 10 8 cell/ml), followed by Pseudomonas sp. (127.9×10 8 cell/g sediment), E. coli HB 101 (62.8×10 8 cell/g sediment), E. coli JM 109 (58.4×10 8 cell/g sediment), and P. fluorescens (42.6×10 8 cell/g sediment). The first-order kinetic adsorption rate coefficient was an exponential function of the total interaction free energy between the bacteria and sediment evaluated at the primary minimum, Δ G 132 TOT (PM). E. coli HB 101 had the greatest kinetic adsorption rate coefficient on the sediment (5.10 h −1), followed by E. coli JM 109 (4.52 h −1), P. fluorescens (2.12 h −1), P. putida (2.04 h −1), and Pseudomonas sp. (1.34 h −1).