Phenol biodegradation and its effect on the nitrification process

摘要

Phenol biodegradation under aerobic conditions and its effect on the nitrification process were studied, first in batch assays and then in an activated sludge reactor. In batch assays, phenol was completely biodegraded at concentrations ranging from 100 to 2500mg l~(-1). Phenol was inhibitory to the nitrification process, showing more inhibition at higher initial phenol concentrations. At initial phenol concentrations above 1000mg l~(-1), the level of nitrification decreased. In the activated sludge reactor, the applied ammonium loading rate was maintained at 140mg N-NH_4~+ l~(-1)d~(-1) (350mg N-NH_4~+ l~(-1)) during the operation time. However, the applied organic loading rate was increased stepwise from 30 to 2700mg COD l~(-1)d~(-1) by increasing the phenol concentration from 35 up to 2800mg l~(-1). High phenol removal efficiencies, above 99.9%, were maintained at all the applied organic loading rates. Ammonium removal was also very high during the operation period, around 99.8%, indicating that there was no inhibition of nitrification by phenol.