carriedout to maintain the influent pH higher than 6.
Besides, in order to avoid hydraulic changes inside the
support which couldbe detrimental for a proper
development of the biofilm, the HRT was fixed at 2.5
days, the OLR applied being increased by adding higher
amounts of the milk analysis effluent to the volume of
the wastewaters constitutedby the other discharges from
the laboratory. In this way, the influent COD was
increased from 2.7 (day 144) to 7.6 g/l (day 200),
corresponding to an OLR increase from 1.1 to 3.1 kg
COD/m3
d. At the end of this period COD removal
efficiencies around90% were obtained, with no significant VFA accumulation andTA higher than 2 g/l.