CHLOROPHENOL DEGRADATION UNDER OXIC AND ANOXIC CONDITIONS

The degradation of 2,4,6,-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP) was evaluated in oxic fluidized-bed reactors. The pseudo-steady-state reactor operation at a hydraulic retention time of 5 hours and feed concentrations of 54 mg/l of 2,4,6-TCP and 64 mg/l of 2,3,4,6-TeCP resulted in stable and effective removal performances on these compounds. GC/MS results indicated over 99 % removal of both 2,4,6-TCP and 2,3,4,6-TeCP. However, PCP degradation at 74 mg/l feed concentration was neglible under these conditions. Further, a denitrifying biofilm was developed which was able to use 4-chlorophenol (4-CP) as the sole electron donor in denitrification reactions. No anoxic biofilm able to degrade 2,4-dichlorophenol (2,4-DCP) or PCP degradation in the presence of potassium nitrate could be developed.