Effect of Raw Water on Biofilm Heterotrophic Growth in Water Distribution Pipes

The growth of heterotrophic (HPC) in water distribution pipes was studied, simulation pipeline reactors were used to simulate the water situation. Water samples were prepared in a laboratory to simulate Class Ⅱ, Ⅲ andⅤ or worse of the surface water standard.Resultsshow that the quantities of HPC in the biofilm are significantly higher than those in the bulk water, and are stabled at 1. 1 × 105, 2.8 × 10⁵, and 5.9 ×10⁵CFU/cm², respectively, after 45 days. UV₂₅₄ concentration and orthophosphate (PO₄^3-) concentration and turbidity in raw water are all positively correlated with the quantity of HPC in the biofilm, and the correlated coefficient are r = 0. 506, 0. 552, and 0. 272, respectively.