In general, biofilms need a biotic or abiotic surface to form. This is why it can be found in many places, such as inside the piping of a water supply. Biofilm allows bacteria to survive in normally hostile conditions. This is due to the high resistance to antibiotics and disinfectants of the polymeric matrices serving as the protective layer of the biofilm.
In the world of water treatment, the presence of biofilm can be problematic since it complicates the disinfection of the water treatment system. As a matter of fact, the formation of biofilms is done in 4 steps.
- Adherence
- Growth
- Maturation, and ;
- Dispersion
Again, when thinking about the water treatment environment, biofilms that can be found in equipment are generally based on algae, protozoa or other various microorganisms.
Problems caused by biofilm
In water treatment equipment, problems caused by biofilm accumulation can be related to treatment efficiency, system flow, internal pressure, treatment quality and can even promote bacterial recontamination of the water.
How to reduce the chances of biofilm formation in a water treatment system
To begin with, choosing the right equipment and materials can reduce the adhesion of biofilm to different surfaces. For example, ABS valves versus stainless steel valves do not have the same resistance to biofilm formation.
Secondly, the internal pressure of the system and the velocity of the water are also parameters that can affect the formation of biofilm since they reduce the adhesion on the walls.
In other words, the use of equipment and materials that are free of high porosity, hard-to-clean areas, cracks or any other characteristic that can promote biofilm proliferation can drastically reduce biofilm formation. In addition, a good CIP (clean-in place) system can also reduce the chances of biofilm formation. However, they are not always effective in removing accumulations.