Author(s): Manjie Li, Zhaowei Liu, Yongcan Chen, Yongyan Wu
Linked Author(s): Manjie Li
Keywords: Iron release, corroded pipe, flow velocity, dissolved oxygen, shear stress
Abstract: Iron release from corroded pipe surfaces is the primary cause of water quality deterioration in drinking water distribution systems. It is generally recognized that an appropriate increase of flow velocity would reduce iron release. However, there are two contradictory viewpoints about this effect mechanism. One declares that the accelerated flow provides more oxygen to preserve the integrity of the iron corrosion scale, a protective layer against further corrosion and iron release. The other statement holds that the raised shear stress applied in pipe surfaces brought by the increase of velocity improves the strength of scale layers and thus reduces the discoloration potential. In this study, a bench-scale testing was conducted to investigate the effect mechanism of flow velocity on iron release. A more than 20-year-old pipe section was used and the water quality parameters, such as pH, dissolved oxygen, turbidity, color, iron, chloride and sulfate, were determined
Year: 2017