AWWA ACE68865

This powerpoint presentation poses the following question, "Why does nitrification improve leaching of Zn and Fe into the water?" A study in galvanized pipe is presented, and tests with galvanized pipe confirmed hypothesis that lower Zn leaching during nitrification result from lower pH and lower DO. A study of pure wire is compared to galvanized pipe-zinc leaching. Presentation conclusions indicate the following: nitrification can cause dramatically lower levels of Zn release from galvanized pipe leaching to the water; nitrification causes lower DO and lower pH, which reduces Zn and Fe leaching in the water; no benefit in terms of weight loss, scale buildup. Includes tables, figures.