Live Legionella (green fluorescence filter) on the electrically heatable CNT POU filters before ohmic heating (A-1 and B-1), dead Legionella (red fluorescence filter) on the composite membranes after ohmic heating at 20 V for 60 s (A-2 and B-2), and live/dead Legionella after the ohmic heating (Orange is combination of green and red fluorescence filters, which indicates inactivation of Legionella after the ohmic heating) on the CNT/PC (A-1, 2, and 3) and the CNT/PVDF (B-1, 2, and 3) membranes.