Nanostructured surface modification of microporous ceramics for efficient virus filtration

The aim of this study was to develop a depth filter working on the electrostatic adsorption principle based on a microporous diatomaceous earth water filter element. The internal surface area of the highly porous elements was coated with a colloidal nanodispersion of hydrated yttrium oxide and subsequently heat-treated under reducing conditions to yield filters featuring uniformly distributed electropositive Y2O3 coatings. Filters prepared in this fashion exhibit a flowrate of 60 l/h at 3 bar and remove in excess of 99.99% of 25 nm diameter MS2 bacteriophages from feed water between pH 5 and 9.