Chlorine dioxide (ClO<sub>2</sub>) may be considered by utilities as an alternative disinfectant to ozone and
chlorine to comply with disinfection requirements set by the Surface Water Treatment Rule and
to control disinfection byproduct (DBP) formation. However, very little is known regarding the formation of biodegradable
organic matter (BOM) by ClO<sub>2</sub> and its effect on the distribution system.
Pilot-scale testing was conducted to determine the potential for ClO<sub>2</sub> preoxidation to produce
BOM while treating blends of California State Project water and Colorado River water.
Preoxidation was followed by conventional treatment (coagulation, flocculation, sedimentation)
and parallel filtration processes (chlorinated and biologically active). The addition of ClO<sub>2</sub>
increased the formation of formaldehyde, carboxylic acids, and assimilable organic carbon
(AOC). Carboxylic acid and AOC levels following ClO<sub>2</sub> were generally lower when compared
to previously conducted work with ozone, whereas formaldehyde levels were higher.
Biofiltration reduced the level of BOM. Annular reactors (ARs) were placed downstream of
filtration to simulate water flow through a distribution system (with a detention time of 6 h).
Biomass measurements in the AR following ClO<sub>2</sub> and biological filtration were similar to
measurements taken in the AR following conventional chlorine treatment. Includes 16 references, table, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 11/15/2004 |
