AWWA ACE70779

This powerpoint presentation begins by providing a brief overview of chlorination and the problems of disinfection byproduct (DBP) formation and and increased corrosion rates. Research objectives were to: investigate haloacetic acid and nitrosamine formation as a result of the interactions between disinfectant residual, pipe materials, and corrosion inhibitors; elucidate the kinetics of disinfectant residual degradation and DBP formation; and, develop empirical and mechanistic models to predict haloacetic acid and nitrosamine formation. Research methodologies are presented, including: simulated distribution system (SDS); material-specific simulated distribution system (MS-SDS); uniform formation conditions (UFC); and, pipeloops. Conclusions for disinfectant degradation kinetics indicate that: first-order kinetics with this source water; fast reaction observed for HOCl; and, corrosion inhibitor affected disinfectant degradation differently with respect to disinfectant type and metals. Conclusions for HAA9 indicate: increased with reaction time and HOCl concentration as expected; no significant impact from corrosion inhibitors; iron produced least HAA9; and, degraded by iron phosphate-associated corrosion products. Conclusions for NDMA indicate: no significant formation under chlorination; initially increased, but leveled off or decreased with reaction time in terms of different corrosion inhibitors; iron produced least NDMA; and, no degradation by iron (+ortho) was observed. Includes tables, figures.