Listed on the US Environmental Protection Agency Contaminant Candidate List 2, Mycobacterium avium is an
opportunistic human pathogen found in municipal drinking water systems. Its survival
and presence in drinking water has been attributed to its resistance to chemical
disinfection by single applications of chlorine, chloramines, ozone, and chlorine dioxide.
However, current disinfection strategies exist that employ the use of a primary and
secondary disinfectant. Inactivation kinetics of M. avium with monochloramine has
demonstrated the presence of an adaptive response triggered by pre-exposure to
relatively low concentrations of monochloramine (<1 mg/L). Subsequent inactivation by
monochloramine at higher concentrations (>5 mg/L) proceeds at a slower rate compared
to that without the pre-exposure. With some utilities using both free
chlorine and monochloramine, the objective of this study was to elucidate any synergistic
and/or adaptive responses exhibited by M. avium to sequential treatment. In addition,
while free chlorine inactivation kinetics has been reported in the literature, a comprehensive
study on the effects of water quality parameters is still needed. Despite the fact that M.
avium is often found within biofilms, this study focused on the inactivation kinetics of M.
avium as suspended cells in order to provide the baseline kinetics for future work with
biofilms. The experimental results presented here are for single-step free chlorine and
sequential free chlorine/monochloramine as a function of pH, temperature, and
disinfectant concentration. Includes 5 references, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 140 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 6 |
| Published : | 11/01/2005 |
