The Automated Hollow Fiber Ultrafiltration (AHFU) method is proposed here as a simple, efficient and rapid virus concentration technique from tap and drinking water sources.
The results reported here extend the testing of the AHFU method to include two Picornaviruses [Poliovirus 2 (vaccine) and Echovirus 1] and Reovirus 3. Their respective mean virus recoveries from between 3 and 100 l of tap water is 88 ± 26, 79 ± 60, and 104 ± 48%.
Various approaches including membrane surface modification, changes in backwash hydrodynamics, modification of the feed and backwash composition, and the use of S35-methionine labelled Poliovirus 2, are used to study the recovery of sorbed Poliovirus 2 from the hollow fiber/solution interface. An increase in the backwash pH to between 9.5 and 10.5 significantly improved Poliovirus 2 recovery. This, together with the labelled experiments, indicates that the virus-membrane interactions are probably electrostatic in nature. Convective polarization during filtration probably brings the virus close enough to the surface for these interactions to occur since virus losses were not detected for a non-permeation recycle experiment.
Because very low Reynold's numbers are used, the flow is in the creeping-flow-regime for both filtration and backwashing (axial and radial). Unless significantly higher Reynolds could be used, enhanced recovery due to purely hydrodynamic forces is unlikely. High Reynold's numbers, of course, are limited by the pressure constraints of the hollow fibers.
Solutions of the mass continuity equation in hollow fibers for fully developed flow with some notes on the Lévêque correlation
