A method (30) for disinfection of a biofilm layer comprises thinning (34) the biofilm layer from an initial thickness to below a given thickness. The method further includes actively drying (36) the thinned biofilm layer for a predetermined active drying interval to disinfect and remove a substantial portion of the body of biofilm bacteria of the thinned biofilm layer. A device (50) for disinfection of a biofilm layer is configured for implementing the method.