Water engineering

Pipe Dreams combined experimental studies on the internationally unique, 600m long temperature controlled pipe test loop facility at the University of Sheffield (Fig.2a) and ambitious live field trials with UK water companies (Fig. 2b).

Carrying on from previous research conducted during PODDS I, II & III project, predicting the discolouration response of distribution networks to changes in hydraulic conditions, Pipe Dreams continued to utilise the temperature controlled pipe test loop facility to investigate the physical factors that effect material accumulation and mobilisation events. In particular the effects of temperature and hydraulics on biofilm formation and subsequent mobilisation of material into the drinking water phase were examined.

Figure 3 illustrates a typical flushing experiment. Shear stress is incrementally increased over time to determine the risk of discolouration as measured by an increase in turbidity, iron and manganese. In addition, changes to the microbial biofilm community are monitored during each step by the removal of coupons. Coupons, designed to limit distortion of the boundary layer flow, are placed along the length of the test rig to allow analysis of microbial accumulation along the pipe wall (see Microbiology section).