The impact of ionic strength and pH on the interaction of Pseudomonas putida to minerals and electrical potential of surfaces

The impacts of the acidity and ionic strength of the solutions were evaluated on the electrical potential of the surfaces as well as the interaction of Pseudomonas putida to quartz and hematite. Zeta potential analysis was performed using the streaming potential technique. Experimental results were performed by the flow cell method. Finally, the extended Derjaguin–Landau–Verwey– Overbeek (XDLVO) theory has been applied to describe bacterial-mineral attachment in terms of the sum of repulsive acid-base and electrostatic interaction energies, and attractive van der Waals interaction energies. The results indicate that the zeta potential is obviously influenced by the presence of bacteria, electrolyte concentration, and pH regions. At higher ionic strengths, charge effects on the bacterial cell surface increase adherence by suppressing the thickness of the diffuse double layer. At pH 5–6, at all ionic strengths, the bacteria adhered more on the surfaces of the minerals. Hematite coupons represented the greatest adhesion at pH 5–6 and an ionic strength 0.1 M. XDLVO theory for the attachment of P. putida to the minerals also confirmed the experimental outcomes. The information obtained in this study is of fundamental significance for the understanding of the survival and transport of bacteria in water distribution, groundwater, and soil systems.