Quick start-up and quick steady-state techniques for UAFFB reactor

Start-up periods of anaerobic reactors need 2 to 3 month to an year (or even more), presumably because of use of non-acclimated anaerobic seed and its slow growth rate. Aerobes commonly excrete glue-like substance such as slime, which aid in attachment of aerobic biofilm to the filter media. The anaerobes do not produce slime and are continuously washed out of reactor. However they attach themselves to slime matrix produced by others (aerobes). The present studies emphasized on initial creation of slime layer on the surfaces of fixed bed media followed by introduction of acclimated anaerobic biomass in bulk, which was expected to get attached to the slime layer, produce biofilm and in turn reduce start-up time. The results are very encouraging and 'Start-up Technique' finalized during these studies is found to be very effective in reducing the start-up period of laboratory scale UAFFB reactor to as low as 15 days even at high organic loading of 5.95 kg COD/day/cum of reactor. The 'Steady-state Technique' is found to be useful in creating the steady-state condition in minimum period of 15 days on increasing the organic loading rate to 7.66 kg COD/day/cum of reactor.