| 摘要 |
<p>This invention provides a method and apparatus for biologically treating wastewater containing fats and oils which can purify waste water containing fats and oils with high efficiency and can efficiently recover energy from an organic component in the waste water, and, in addition, can realize stabilization of methane fermentation treatment, improved treatment efficiency, a size reduction in a methane fermentation tank, an improvement in the separation efficiency of fats and oils from the waste water containing fats and oils, a reduction in amount of the occurrence of sludge and the like. Waste water containing fats and oils is subjected to coagulation treatment in a coagulation reaction tank (2) and is then subjected to pressure floatation treatment in an oil-and water separation tank (a pressure floatation tank) (3). The water subjected to the pressure floatation treatment is biologically treated in an acid production tank (4), a high-load anaerobic treatment tank (5), and an aerobic treatment tank (6) and is then subjected to solid-liquid separation in a sedimentation tank (7). The pressure floated sludge is subjected to methane fermentation treatment in a methane fermentation tank (8) and is then dehydrated with a sludge dehydrater (9). Excess anaerobic sludge and/or excess aerobic sludge in the step of biological treatment is introduced into the methane fermentation tank (8). Alternatively, excess anaerobic sludge in the step of biological treatment, excess aerobic sludge, and excess digestion sludge in the methane fermentation tank (8) is introduced into the coagulation reaction tank (2).</p> |
