摘要:
Provided is a method for treating organic waste water, which are capable of realizing compact equipment by reducing the quantity of a sludge to be treated. Organic waste water (A) is subjected to an aerobic biological treatment in biological treatment tank (3). Then, solution (B) obtained by the treatment in the biological treatment tank (3) is solid-liquid separated into treated water (C) and sludge (D) in precipitation tank (5). A part of the sludge (D) separated in the precipitation tank (5) is returned to the biological treatment tank (3) through route (6). A part (E) of the sludge separated in the precipitation tank (5) is concentrated by concentration device (8). Thereafter, the concentrated sludge (E) is solubilized by thermophilic bacteria in solubilizing tank (10).