Influence of flow velocity on the distribution of bacteria in biofilm and water - Executive Summary - Flow velocity not an influence on the distribution of microorganisms in biofilm and water

Differences in hydraulic regimes do not lead to different compositions of bacterial populations in water and biofilm. This is the outcome of a study in which the KIVODIS pilot installation was used to analyse four different hydraulic regimes. Water and biofilm samples were taken to determine the ATP concentrations, KG25 numbers, specific qPCR gene copies and the bacterial population (using Next Generation Sequencing, or NGS). Information about the biofilm on the pipe wall in the distribution system is important for ensuring the microbial water quality at the tap, since the water quality is affected by the level of regrowth. Exchange between the water phase and biofilm was limited.

Interest: increase understanding of the distribution of bacteria in biofilm and water, and the effects of hydraulics on the distribution – The extent to which the exchange of microorganisms between the water phase and the biofilm on the pipe wall in the distribution system influences the microbial water quality is unknown. The effect of the hydraulics is also unknown. For water utilities it is important to know whether opportunistic pathogens and legal regrowth parameters occur in the drinking water. The level of regrowth has a possible influence on the microbial water quality at the tap. This study provided greater insight into the exchange of microorganisms between water and biofilm under different hydraulic regimes.

Report – This research is described in the report Invloed van hydraulica op de uitwisseling van bacteriën tussen biofilm en water (BTO-2018.090).