Biofilms are the colonization of microorganisms on a solid surface such as the interior of pipes, and contain a self-produced extracellular matrix.  The use of disinfectants to remove the biofilm, is often ineffective, and may also generate drug resistance in bacteria.  Nanobubbles ability to generate powerful Hydroxyl radicals coupled with the bubble's ability to penetrate and break up the biofilm makes them particularly effective in removing the colonization.