Chloramine decay studies were conducted to evaluate the impact of various water quality
parameters on the decay characteristics of the San Francisco Public Utility Commission
(SFPUC) water, to predict disinfectant levels within the distribution system, and the potential for
nitrification. The results of the studies show that overall, SFPUC water is very stable, meaning
that decay rates are slow compared to other surface water supplies. The studies indicated that for
SFPUC waters, pH had the most significant effect on chloramine decay; chloramine decay was
slower at higher pH values (between pH 8.8 and 9.0), which are currently maintained for
corrosion control.
The use of booster chlorination was also evaluated as a possible means of maintaining or
increasing the total chlorine residual within the distribution system. Although chlorine added to
chloraminated test water combined with the free ammonia-N that was liberated as a result of
chloramine decay, the ability to properly feed sodium hypochlorite is a critical factor in
determining whether or not to implement this practice. An evaluation of free ammonia-N data
from a similar water system supported the conclusion that boosting the chloramine residual with
sodium hypochlorite is not a practical alternative for the SFPUC system.
Includes 7 references, table, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 190 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 8 |
