| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a sewage treatment method which enables a reduction in the amount of generated surplus sludge with no deterioration in water quality of treated water. <P>SOLUTION: The sewage treatment method comprises the process of biologically treating sewage, a process for performing solid-liquid separation of the biologically treated sewage to obtain treated water and return sludge, the process of obtaining drawn-out sludge from a part of the return sludge, the first solubilization process of solubilizing the drawn-out sludge by alkali treatment, the second solubilization process of biologically decomposing the alkali-treated sludge under an anaerobic, anoxic, or microaerophilic condition to solubilize it, the third solubilization process of further solubilizing the biologically treated sludge to convert it into low-molecular material, and the process of returning the low-molecular sludge to the biological system. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
