DEGRADATION OF 4-CHLOROPHENOL IN DENITRIFYING FLUIDIZED-BED PROCESS

Chlorophenol degradation.by dissimilatory nitrate reduction was studie d in an anoxic fluidized-bed reactor. 4-Chlorophenol (4-CP) served as a carbon source for denitrification although both 4-CP and nitrate rem ovals remained incomplete (23-82 and 9-60%, respectively) at 5 h hydra ulic retention time. Under varying experimental conditions, 1.9-2.5 mg 4-CP was degraded and dechlorinated per 1 mg NO3-N reduced. This is h igher than the theoretical 4-CP/NO3-N ratio of 1.8 and the difference is likely due to aerobic degradation in the presence of trace concentr ations of oxygen. The mass balance based on inorganic chloride release and disappearance of the parent compound gave further evidence of chl orophenol degradation in the system.