Controlling copper corrosion in new construction by organic matter removal

Abstract

A new elementary school with persistent elevated copper corrosion by‐product release evaluated pH increase, orthophosphate dosing, and granular activated carbon (GAC) treatment as potential corrosion control measures using bench‐scale experiments. Removal of natural organic matter (NOM) with temporary GAC treatment facilitated the formation of a copper scale with a permanently diminished (> 85%) solubility via an accelerated natural scale‐aging process. Increasing the pH and adding a high dose of orthophosphate were also effective for decreasing copper release but presented significant long‐term drawbacks, and their benefits were reversed if the treatments were discontinued. Temporary GAC treatment may be a holistically attractive option to reduce copper corrosion problems in new construction in certain waters with high levels of NOM.