1992 年 28 巻 p. 93-103
Influence of sulfate reduction on filamentous bulking in the activated sludge process was examined in two types of laboratory units. One is the conventional system and the other is the anaerobic-oxic system. When the units were operated with acetate, sulfate reduction occur in the oxic tank and filamentous bulking due to Type 021N occurred. However, in the high mineral conditions, Type 021N could not grow predominantly. When the units were cultivated with acetate and peptone, sulfate reduction occurs in the anaerobic tank and/or settling tank. Sulfate reducing bacteria did not utilize acetate. They utilized organic acids or amino acids similar to lactate produced from peptone and decomposed biomass. Sulfate reduction could be a cause for filamentous bulking due to Type 021N which could utilize sulfide as energy source.