KINETIC-ANALYSIS OF VIRUS ADSORPTION AND INACTIVATION IN BATCH EXPERIMENTS

The mobility and ecology of viruses in natural environments is strongly influenced by the adsorption of virus particles to sand or soil surfaces. This binding process is frequently studied by conducting batch experiments in which fluid suspensions of virus particles are contacted with the adsorbent of interest. In this report, a simple first-order kinetic theory is presented which accounts for many of the complicated interactions that can occur when viruses contact an adsorbent in a batch system. Closed-form solutions and numerical simulations of the model indicate that four classes of virus-surface interactions can be identified, including quasi-equilibrium adsorption, quasi-equilibrium adsorption with surface sinks, quasi-equilibrium adsorption with reduced inactivation, and direct irreversible adsorption. Based on these results, a new experimental approach for studying virus-surface interactions is proposed and tested using a model system consisting of bacteriophage lambda and Ottawa sand. Fluid samples were collected from sand-containing and sand-free virus suspensions over the course of 5-6 days and analyzed for plaque forming units (PFU). These experiments were repeated using three different pH values and six different electrolyte compositions. Nondimensionalization of the PFU data from the sand-free suspension collapsed all of the data onto a single fine, as predicted by the kinetic model. When plotted in a nondimensional format, data from the sand-containing suspensions exhibited behavior which could readily be interpreted within the context of the kinetic model. These results suggest that the proposed approach offers a powerful alternative to conventional methods for studying virus adsorption at the solid-liquid interface, and for predicting the potential mobility and fate of viruses in porous media.