Descrição
An up-flow fixed bed reactor (UFBR) was established
to investigate the biodegradation of fluorobenzene
(FB) under a number of operating conditions, which
included variation in the concentration of FB in the feed
stream (up to 180 mg l−1) and temporary suspension of
feeding. Degradation of FB was followed for a period of
8 months under a continuous flow regime. During the operation
of the UFBR, FB was never detected in the reactor
effluent, being biodegraded by the microbial biofilm or
adsorbed to the granular activated carbon (GAC). Biodegradation
of FB was observed from the beginning of the
reactor operation, and overall, it accounted for 50% of the
total amount fed to the bioreactor. High organic loads of FB
(210–260 mg d−1 dm−3) were found to affect the biological
removal efficiency, possibly due to an inhibitory effect
caused by the higher FB concentrations fed to the bioreactor
(149–179 mg l−1). When FB feeding was suspended for
1 month, biodegradation continued, indicating that the
adsorbed FB became bioavailable. Biofilm bacterial dynamics
were followed throughout the UFBR operation by
denaturing gradient gel electrophoresis and plate-counting
techniques, showing that a quite stable community was
found in the bioreactor, and this was mainly attributed to the
high selective pressure exerted by the presence of FB.
; Jorge, R. Ferreira 
