AWWA WQTC69239

This powerpoint presentation begins by providing the problem description that includes the following: distribution system nitrification, chloramines - ammonia, growth rate and inactivation rate, and ammonia-oxidizing bacteria (AOB); current research focus is on inactivation rate - rate constant, and mixed cultures - biofilms; and, the goal is prevention and control. Batch disinfection models are presented, along with viability measurements, previous and current research, LIVE/DEAD® BacLight™, Propidium Monoazide (PMA), Quantitative Real-Time PCR (qPCR), control experiments, modeling (delayed Chick-Watson), and kinetic summary. Presentation conclusions indicate the following: successful PMA-qPCR application for N. europaea and monochloramine; Lag phase (b) most likely a result of stationary phase growth, no clustering evident - microscopic cell counts, and similar in all three methods (~500 mg-min/L); rate constant (k) PMA-qPCR slower but comparable to LIVE/DEAD, and LIVE/DEAD methods significantly different; future research should include buffer choice and growth state. Includes 3 references, figures.