A MESOPHILIC DIGESTION OF BREWERY WASTE-WATER IN AN UNHEATED ANAEROBIC FILTER

An anaerobic filter (5.8 m(3)) operated at ambient temperature was use d to treat brewery wastewater: The hydraulic retention rime was mainta ined at a constant value (10 h) throughout the trial. The start-up per iod, to achieve fully stabilized conditions was 6 months. At an applie d loaning rate of about 8 kg COD/m(3)d, the mean COD removal was 96% a nd the mean gas production was 7.1 m(3)/d. The methane content of the biogas was higher than is normally found. During the steady state regi me it was 80-95%. The results show that, when the ambient temperature is high, an anaerobic filter can operate in the mesophilic range and b e used to treat brewery wastewater successfully. (C) 1998 Elsevier Sci ence Ltd. All rights reserved.