Abstract
The effects of influent substrate concentration and high loading rate on characteristics of substrate removal in methanogenic phase of anaerobic two phase digestion were investigated by using anaerobic fluidized bed reactors. Two kinds of substrates were used. The first one was composed of acetic acid and the second one was composed of acetic acid, propionic acid, butyric acid and glucose. Whichever substrate was used, influent substrate concentration affected the retaining characteristics of biomass. In case of using acetic acid substrate, effluent substrate concentration increased as influent substrate concentration increased. Two kinds of substrates were used at loading rate of 30kg-COD·m-3·d-1. The one was mixed acid containing glucose, and the other was acetic acid. In both cases, substrate removal efficiencies of the reactors were high. However, the effluent quality of the reactor to which acetic acid was added were unstable.
