3.3 Time required for the concentration of virusesSixteen water samples were processed using smaller MF and UFcartridges (CEP-2-E-4MA and UFP-100-C-4MA) with filter surfaceareas of 420 and 650 cm2respectively and the rest of the sampleswere processed using larger cartridges (CFP-2-E-9A and UFP-100-C-9A) with filter surface areas of 8400 cm2and 1.15 M2.