A nine month pilot study simulated raw and settled water ozonation and conventional treatment.
The ozone module set-up included six, six-inch diameter plexiglass columns, each roughly 90
inches tall, and was capable of achieving very high ozonation CTs to simulate Cryptosporidium
inactivation. Monochloramine, ammonia, and pH adjustment were evaluated for bromate control
at various ozone doses, temperatures, and disinfection CTs.
Treatability studies were performed on the Trinity River, near Houston, Texas. The Trinity
River currently supplies many utilities in the state of Texas. Although raw water bromide levels
are only moderate (0.10-0.20 mg/L), ozone doses needed for Cryptosporidium inactivation could
easily produce bromate levels above the 10 ug/L MCL. Ozone disinfection CT goals for the
project for Cryptosporidium inactivation were established based on previous and separate work
conducted by American Water Works Association Research Foundation.
For the chloramine evaluations, monochloramine was formed by adding chlorine and ammonia
at a 5:1 ratio. Total chlorine residual of 2 mg/L prior to raw or settled water ozonation provided
better control than either ammonia addition or pH adjustment prior to ozonation. For example, a
total chlorine residual of 2 mg/L consistently produced bromate levels less than 5 ug/L for a
range of disinfection CTs and water temperatures.
Complete study results for bromate as well as other ozonation byproducts, such as aldehydes, are
presented. Includes 11 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 400 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 14 |
| Published : | 06/16/2002 |
