| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method and a device for treating organic waste water by which phosphorus can be recovered in the biological treatment of organic waste water, increase in phosphorus and in the COD in the treated water can be prevented, and the production amount of excess sludge can be decreased while the use efficiency of ozone is increased. SOLUTION: In the method and the device for treating organic waste water by activated sludge in a biological treating tank containing an adjusting tank and an anaerobic tank, a part of the activated sludge in the biological tank is supplied to a liquefying device for liquefaction and the liquefied activated sludge effluent from the liquefying device is supplied to the adjusting tank where the sludge is mixed by stirring and subjected to acid fermentation. The liquid after acid fermentation is supplied with organic waste water to the biological treating tank, and a part of the activated sludge mixture liquid in the anaerobic tank of the biological treating tank is subjected to solid liquid separation. Phosphorus in the supernatant liquid is recovered, the liquid after the phosphorus is recovered is returned with the above separated sludge to the biological treating tank.</p> |
