Bacteriophage inactivation at the air-water-solid interface in dynamic batch systems

Bacteriophages have been widely used as surrogates for human enteric viruse s in many studies on virus transport and fate. In this investigation, the f ates of three bacteriophages, MS2, R17, and (phi X174, were studied in a se ries of dynamic batch experiments. Both MS2 and R17 readily underwent inact ivation in batch experiments where solutions of each phage were percolated through tubes packed with varying ratios of glass and Teflon beads. MS2 and R17 inactivation was the result of exposure to destructive forces at the d ynamic air-water-solid interface. phi X174, however, did not undergo inacti vation in similar studies, suggesting that this phage does not accumulate a t air-water interfaces or is not affected by interfacial forces in the same manner. Other batch experiments showed that MS2 and R17 were increasingly inactivated during mixing in polypropylene tubes as the ionic strength of t he solution was raised (phi X174 was not affected). By the addition of Twee n 80 to suspensions of MS2 and R17, phage inactivation was prevented. Our d ata suggest that viral inactivation in simple dynamic batch experiments is del,dependent upon (i) the presence of a dynamic air-cater-solid interface where the solid is a hydrophobic surface), (ii) the ionic strength of the s olution, (iii) the concentration of surface active compounds in the solutio n, and (iv) the type of virus used.