STABILITY OF ANAEROBIC FILTERS PACKED WITH DIFFERENT SUPPORT MATERIALS

Two anaerobic filters were subjected to shock treatments in similar co nditions, by suddenly lowering the temperature of the reactors by 10 d egrees C in one case and by suddenly stopping the addition of alkali t o the feed in a second experiment. In both cases the reactor packed wi th polyurethane sponge showed no variations in the different analysed parameters with respect to the values of the steady-state of reference , while the filter packed with rocks was more affected by the temperat ure shock than by the decrease of the pH of the feed.