What is biofilm?

Biofilm consists of microorganisms that exist in wet conditions. They form a slippery layer adhering to solid surfaces and contain a large number of bacteria.

Biofilm can exist on living and non living surfaces;

An example of biofilm on a living surface is dental plaque on the teeth of most animals. Untreated, this can lead to  tooth decay and gum disease.

An example of biofilm on a non-living surface is the slimy covering on a stone or rock at the bottom of a stagnant pool.

 

The formation of biofilm

Biofilm in the water industry

Biofilm in drinking water industries is responsible for a wide range of water quality and operational issues.

As microbes grow, they attach themselves to the wet surfaces of a distribution system. They protect themselves from disinfecting agents by forming biofilms. 

Biofouling alone contributes to more than 45% of all membrane fouling and has been reported as a major problem in ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membrane filtration.

There are several strategies for controlling membrane biofouling:

  • Adding disinfectants and biocides
  • Adding specific molecules to influence quorum sensing (QS) in biofilms to trigger their dispersal
  • Modifying the membrane surface (or spacers) to reduce biofilm attachment and growth

Most current biofouling control techniques are either effective only initially due to the ability of the biofilms adaptation to the conditions over time.  Or the process needs a repeated application to control biofouling effectively in the long run.

New methods are needed to control persistent biofouling.

 

Do you have issues in your industry with biofouling?

 

Related content: Membrane fouling and biofilm in water systems