Coating defects that cannot be clearly assigned represent a challenge for the user. Where should you start now? How do you narrow down the search for faults without taking excessive countermeasures? If you know your enemy, you can react better.
99.9% of bacterial cells in the biofilm of drinking water cannot be propagated on standard media (Szewzyk et al., 2000). In addition, 2/3 of the population is present in a dormant state. This "viable but noncultable" state (VBNC) can lead to renewed and visible contamination shortly after cleaning.
Biofilms mainly form on surfaces. This is the extracellular polymeric substance (EPS). Around 90 % of EPS sticks to surfaces, so it is advisable to take a closer look at the area.
Sealants and silicone pipes are particularly problematic! Presumably the release of plasticizers on such materials increases contamination.
After checking the various influencing factors, the next step is to implement suitable measures.
The first step here must be a basic/system cleaning. The biomass must be removed. The focus here is on limescale incrustations or deposits. Limescale deposits are porous and provide a refuge for microorganisms. Electroplating systems in particular are constantly being extended and converted. This results in pipe systems that are almost impossible to keep track of. If areas are only rarely flown through, breeding areas and hotbeds of germs quickly form, which first have to be discovered. Due to the increased surface area (exchanger resins and gravel filters), ion exchanger systems offer plenty of space for biofilms to form. This has a negative effect on the service life of the exchangers - biofilms prevent ion exchange. If the regeneration interval is shortened, this can also indicate a build-up of bacteria in the system. There is a lot to consider here. Expert support is advantageous.
