METHOD FOR PREVENTING AND REMOVING FILIFORM BULKING USING BACTERIOLYTIC ENZYME FOR FILAMENTOUS BACTERIA

摘要

PURPOSE:To achieve a rapid effect to prevent filiform bulking of active sludge without inhibiting propagation of useful microorganism and without giving undesirable influence on the environment by adding subtilisin having a bacteriolytic action on filamentous bacteria to an active sludge tank. CONSTITUTION:Subtilisin having a bacteriolytic action on filamentous bacteria is added to an active sludge tank. The subtilisin is added by 10ppm to 10000ppm, preferably 100ppm to 1000ppm to the active sludge. The subtilisin is directly added to the active sludge tank or while mixed with return sludge or waste water flowing into the tank. By adding subtilisin to an active sludge tank in which the bulking is produced, filamentous bacteria are subjected to selective and rapid bacteriolysis action and bulking can be effectively avoided.