ACTIVATED SLUDGE MATERIAL, REDUCTION METHOD OF EXCESS SLUDGE AMOUNT IN BIOREACTOR, AND MAINTENANCE METHOD OF BIOREACTOR

摘要

Excess sludge production in a bioreactor of a wastewater treatment plant in which excess sludge is being produced is reduced by adding an activated sludge material having a chitinase specific activity of at least 150 Units/g-MLSS and a pectinase specific activity of at least 120 Units/g-MLSS to the bioreactor. After the addition of the activated sludge material, the bioreactor is controlled by adding the activated sludge material when any one of the chitinase activity, the pectinase activity, and the protease specific of the sludge in the bioreactor drops below the lower limits of 50 Units/L, 40 Units/L, and 0.3 Units/L, respectively.