Biofilters seeded with mixed-culture nitrifiers from Lake Austin, Texas, and fed nutrient and
Lake Austin water biodegraded the four trihalomethanes (THMs) commonly found in treated
drinking water - bromoform, chloroform, dibromochloromethane, and dichlorobromomethane.
THMs were degraded by cometabolism, and degradation increased with increased THM
bromine substitution and increased total ammonia-nitrogen biodegradation. Overall, these
experiments resulted in sustained THM removals ranging from 10 to 60% for varying operating
conditions. Three operational issues were also studied: THM product toxicity, nutrient
limitations, and monochloramine inhibition of ammonia and THM degradation. The cometabolism
stability index represents a simple and useful parameter for evaluating the likelihood of
product toxicity problems in biofilter operation. Nutrient limitations (e.g., iron and copper)
may exist for natural water sources, and supplemental nutrients may be needed to achieve
maximum THM degradation rates. Influent monochloramine concentrations of 1 mg/L (or
less) as Cl<;sub>;2<;/sub>; appear to be a good target for stable operation of developed biofilm. Includes 34 references, tables, figures.
| Edition : | Vol. 98 - No. 12 |
| File Size : | 1
file
, 370 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 13 |
| Published : | 12/01/2006 |
