| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To efficiently treat oil and fat-containing waste water in a wide concentration range without deteriorating the quality of treated water and to reduce the amount of the surplus sludge to be generated upon the purification of oil and fat-containing waste water by a sludge predation system. <P>SOLUTION: In the biological treatment method for organic waste water where oil and fat-containing waste water is introduced into a first biological treatment tank 3 and is subjected to biological treatment with non-coagulable bacteria, and the non-coagulable bacteria-containing treated water from the first biological treatment tank 3 is introduced into a second biological treatment tank 4, and is subjected to activated sludge treatment, the oil and fat-containing waste water and/or a reaction liquid in the first biological treatment tank 3 is subjected to emulsification treatment. By emulsifying and dispersing oil and fat insoluble in water by the emulsification treatment, the contact area with the bacteria is increased, thus organic substance including the oil an fat in the oil and fat-containing waste water can be converted into dispersible bacteria without beforehand separating the oil and fat from the oil and fat-containing waste water. Then, the dispersible bacteria are preyed upon by fixable protozoa, so as to be removed in the second biological treatment tank 4. In this way, the reduction in the quantity of surplus sludge is made possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
