An investigation into bacterial colony formation on inner pipe surfaces with various pipe geometries in water...

The flow characteristics induced by various pipe geometries have significant implications for bacterial colonization and water quality stability within drinking water distribution systems (DWDSs). This study established a pipeline circulation system designed to simulate the operational conditions of actual DWDSs. Through the application of a coupon insertion methodology, we investigated how hydraulic conditions, generated by different pipe configurations, influence bacterial colonization and biofilm initiation. The findings indicate that, at the genus level, Aquabacterium, Dechloromonas, Caulobacter, and Acidovorax were dominant during the initial stages of biofilm formation. Within areas characterized by localized hydrodynamic conditions, the shear-resistant genus Caulobacter exhibited increased proliferation in the hydraulically complex elbow regions. Conversely, Aquabacterium, known for its diverse nutrient utilization capabilities, dominated in pipe expansion areas where nutrient exchange was slower. Furthermore, the results reveal that the compositions of bacterial communities adhering to the interior pipe surfaces were significantly distinct from those present in the bulk water. These microbial colonies pose serious threats to drinking water safety, necessitating routine assessments. The sampling technique proposed in this study is characterized by its cost-effectiveness, operational simplicity, and minimal intrusion, demonstrating considerable promise for advancing research on biofilms within DWDS infrastructure.