Abstract
The effects of substrate composition on the characteristics of substrate removal and biofilm formation in methanogenic phase of anaerobic two phase digestion were investigated by using laboratory-scale anaerobic fluidized bed reactors with packed media of activated carbon. Three kinds of substrates were used. The first one was composed of acetic acid and the second and third ones were composed of acetic acid, propionic acid and butyric acid. A small amount of yeast extract and glucose were added to the second and third ones, respectively. In the experiments in which yeast extract or glucose was added to the mixed acid substrates, the substrate removal efficiencies were higher than in the experiment using acetic acid substrate. The biofilm formation was accelerated by using the mixed substrate to which yeast extract was added.
