Physical Treatments

Heat
Pharmaceutical Water-for-Injection systems use recirculating hot water loops (greater than 80°C) to kill bacteria. According to Mittelman (1986), when these systems are used on a continuous basis, planktonic bacteria are killed and biofilm development is reduced. Biofilms are even found in hot water (80°C). Periodic hot water sanitization can also be used to destroy bacteria in biofilm, but according to Collentro (1995) this requires a temperature of 95°C for a period in excess of 100 minutes. This would not be practical in an animal drinking water system!

Mechanical removal
From Mittelman: "Heavy biofilms cannot be removed from storage tank walls by the use of chemicals alone; mechanical scrubbing or scraping, high-pressure spraying, or a combination is also required. Mechanical removal of biofilm from distribution systems is impractical." For RO system maintenance, we don’t routinely scrub storage tanks, but there is usually a continuous low chlorine level in the stored water, so heavy biofilms aren’t allowed to develop.