Ca-Facilitated Adhesion of Bacteria on the Na-Montmorillonite Surface.

The adhesion of bacteria on clay surfaces strongly affected their migration and distribution in soil and water. Bacterial adhesion experiments on the Na-montmorillonite (Na-MMT) surface were conducted to determine the role of Na-MMT in the bacterial adhesion process and to prove the validity of the isotherm and kinetic theory for the bacterial surface adhesion in the presence of Ca ions. Batch adhesion experiments with bacteria on the Na-MMT surface were carried out with varying time frames, temperatures, bacterial concentrations, and Ca ion concentrations. The adhesion capacity of Na-MMT significantly correlated with the Ca ion concentration, temperature, time frame, and bacterial concentration when Ca ions were present. The adhesion morphology of the bacteria onto the Na-MMT surface, observed through the zeta-potential and atomic force microscopy (AFM), additionally demonstrated that the bacterial adhesion onto the Na-MMT surface was dominated by the nonelectrostatic force.