オキシデーションディッチにおける放線菌の増殖に関する調査研究

抄録

The OD (oxidation ditch) systems occasionally produce significant amounts of foam and scum.Then in this study, some OD plants were examined and the number of actinomycetes cells was assessed. The results obtained were as follows: Scumming was considered to be due to the growth of actinomycetes in the OD tank (aeration tank), which was largest in the OD process. In case of scumming, actinomycetes was found to be transferred from the MLSS to the scum and thickened. Then the multiple of thickening ranged from 1.5 to 5.8. The values of the specific growth rate calculated by the data of the three plants, were between 0.07 and 0.11 (1/day), which were about one half as large as that of the conventional activated sludge process. By comparison between the new scum and the old scum, actinomycetes was considered to increase not in the scum, but in the MLSS.