Advanced biomass formation potential of pipe materials for drinking water distribution systems: A semi-automated biomass formation potential

Pipe materials used in drinking water distribution systems should be subjected to biostable suitability tests before deployment. The biofilm formation potential of pipes made from polyvinyl chloride (PVC) and ductile iron (DI) coated with different layers, namely, cement and epoxy, were investigated. The results showed a significantly higher biomass formation potential for cement-coated DI than other materials, while the PVC materials manufactured by the same company for different purposes were not significantly different in this regard. Furthermore, the results of biomass formation potential were compared with other national standards and showed that the selected materials, including epoxy- and cement-coated DI, and two out of five PVC materials were unsuitable for use in water distribution systems. In this study, stabilizers used for PVC pipes were also prepared in the form of coupons and tested to observe their biomass formation potential. The obtained results provide a basis for selecting stabilizers in drinking water pipe production to ensure biostability of the materials. Moreover, an advanced semi-automated biomass formation test was conducted for the first time. The changes in biomass formation of the selected materials were monitored in real time using an automated online flow cytometry system that revealed the bacterial growth behavior and fingerprint changes during the incubation period.