Effect Of Epoxy Lining On Water Safety In Urban Water Distribution System

Urban water distribution systems(WDS) play an important role in supporting industrial development and providing citizens with safe drinking water. However, pipe aging leads to new challenges in urban water supply management. In cast iron pipelines, rust will be generated in the pipes’ interior and WDS node pressure will decrease after several years. So the pipeline rehabilitation is being paid increasing attention to, nowadays.The material used in the epoxy lining technique is epoxy resin. It removes rust on the inner surface of pipes with silica sand and sprays epoxy resin into the inner surface of pipes. The new lining layer shows better protection performance and an increased pipe life expectancy.The objectives were to research the dissolution characteristics of three different pipe-- an old cast iron pipe, a cement mortar lining pipe and an epoxy lining cast iron pipe-- and to understand the effect of epoxy lining on water quality and node pressure in the distribution system. Water contact time, pH, temperature, chlorine concentration and water source were taken into account. Data on water quality and node pressure in a water distribution system in community X were collected and analyzed with regard to the influence of epoxy lining on the water pipeline system.It could be shown that the epoxy lining cast iron pipe had advantages over the other two pipe types: Its turbidity was significantly lower, its pH stable, and its chlorine consumption and the dissolution of Fe and Mn were reduced. However, it was found that the concentration of organic matter was increased in the epoxy lining cast iron pipe. In addition, the node pressure head in the previously mentioned water distribution system was increased by 0.46 m on average after the epoxy lining technique was applied. Therefore, this technique could improve hydraulic conditions in the pipe system and reduce its energy consumption. The concentration of organic matter and Fe was reduced to 60% and 8%, respectively, in one week after the epoxy lining was applied. The concentration of chlorine also decreased to 86% after the epoxy lining. Moreover, it was also observed that there was no remarkable change in turbidity, pH, Mn, Cr, Pb and Cu concentrations.