Granular activated carbon (GAC) was used as supporting medium for bact
eria in anaerobic process. The effectiveness of using GAC was examined
with laboratory-scale experiments. Synthetic wastewater containing ph
enol was converted to methane more successfully in fluidized bed using
GAC. Fluctuation in influent concentration of phenol was intentionall
y made to examine the dynamic response of the process. Temporary incre
ase of influent phenol from 400 mg/l to 1000 mg/l, 2000 mg/l, and even
to 4000 mg/l for 4 days did not affect the effluent phenol as much as
methane production because adsorption and desorption capacity by GAC
functioned as stabilizer of the fluctuation. The adsorbed phenol was t
hen gradually degraded into methane. Higher biomass concentration and
lower adsorbed phenol were observed in the top part of the fluidized b
ed than in the bottom part. (C) 1997 IAWQ. Published by Elsevier Scien
ce Ltd.