AWWA WQTC69364

This powerpoint presentation begins by presenting study objectives that include the following: to investigate how low-level intrusions,from different sources, impact thechlorine and chloramine residuals,and the potential for microorganismsurvival; and,if water is intruded through a leakafter a low-pressure event, determine if microbialsurvival may be enhanced if thematrix exerts a disinfectant demand. Batch disinfection kinetics studieswere conducted in continuously-mixed500 mL glass reactors(maintained at 10ºC). Study conclusions indicate the following:understanding matrix characteristics is important fordetermining the significance of a low-level intrusion, thehigher the total organic carbon (TOC), the greater the potential to impactdisinfection residuals;free chlorine residuals are more sensitive to wastewaterintrusion than chloramine residuals, 0.1% intrusion ofsewage caused up to 50% decrease (instantaneous) inchlorine residuals but did not impact chloramine residuals; maintenance of a disinfectant residual provides aprotective barrier against low-level intrusions, and microbialrisk assessments are required to determine the extent ofthe barrier; and,low-level intrusion events are likely to go undetected byonline water quality monitors. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

10

File Size:

1 file , 1.1 MB