Chlorination in drinking water systems has been instrumental in decreasing waterborne
diseases. However, free chlorine can interact with organics in the water to form
regulated disinfection byproducts (DBPs). Therefore, many water utilities are switching
to chloramines to reduce the levels of DBPs. Chloraminated systems can suffer from
nitrification when free ammonia is converted to nitrite and then nitrate. Nitrification
episodes in chloraminated drinking water distribution systems are thought to be caused
by autotrophic nitrifiers. An observation has been that there is an increase in
heterotrophic bacterial abundance during nitrification, and the study hypothesis is that
heterotrophs may also be contributing to nitrification since it is known that these bacteria
are capable of nitrification in many environments.
In a reactor that simulates premise plumbing, nitrification was found to be
affected minimally by chlorite treatment, suggesting a possible contribution to the
nitrification process by organisms other than autotrophic bacteria. A heterotrophic
nitrifying bacteria was isolated from the effluent of this reactor.
The isolation of organisms such as the one in this study can provide a positive
control for the design of a molecular method to track heterotrophic nitrification and thus
possibly predict nitrification events in the DWDS. Likely gene targets for tracking
heterotrophic nitrification include the heterotrophic ammonia monooxygenase (AMO)
gene and the heterotrophic hydroxylamine oxidoreductase (HAO). Includes 25 references.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 770 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 7 |
| Published : | 11/01/2008 |
