Epoxy lining influence on recycled water quality during pipeline transit for potable reuse

An epoxy treatment was applied to a pipeline used to convey advanced treated recycled water from a purification facility to a recharge site. The epoxy treatment was applied to prevent further deterioration (corrosion) of the interior cement mortar lining (CML). A soil column study was conducted to evaluate the effect of the epoxy liner on the clogging potential of water before and after conveyance. The clogging potential was represented by differences in the column's relative hydraulic conductivity and water quality, between the treatment plant and injection site, before and after epoxy lining. Hydraulic conductivity of columns at the injection well site declined rapidly before epoxy and improved considerably after epoxy application. Total suspended solids (TSS) and cellular adenosine triphosphate (cATP) median concentrations improved significantly. Before epoxy, TSS increased with pipeline transit from 0.005 to 0.053 (mg/L) compared with 0.009mg/L after epoxy. Before epoxy, cATP increased from 0.14 to 1.6 pg/ml across pipeline transit compared with 0.37pg/ml after epoxy. Aluminum and nitrate followed similar trends. Results indicate that epoxy liner reduced the clogging potential of high purity recycled water, likely due to a decrease in particle and biomass load (clogging constituents) accumulated during pipeline transit.

Automated summary

This study evaluated the effect of an epoxy liner on the clogging potential of water conveyed through a pipeline. The results showed that the epoxy liner can effectively reduce the clogging potential of recycled water, likely by reducing the accumulation of particles and biomass load during pipeline transit.