| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the efficiency of sludge volume reduction in anaerobic digestion treatment in which digested sludge is subjected to solid-liquid separation, and the separated sludge is returned to an anaerobic digestion tank. SOLUTION: The digested sludge from the anaerobic digestion tank 1 is subjected to solid-liquid separation in a precipitation tank 2, and the separated liquid is subjected to solid-liquid separation by a centrifugal separator 3. Part of the concentrated sludge of the precipitation tank 2 is discharged outside a system as excess sludge, and the rest is returned to the digestion tank 1. The separated liquid of the centrifugal separator 3 is discharged outside the system as treated water, part of the concentrated sludge, after being reformed by an ozone treatment tank 5, is returned to the digestion tank 1, and the rest is returned to the digestion tank 1. By doing the solid-liquid separation of the digested sludge in two stages, the solid content leaked into the separated liquid is reduced to hold the sludge in the digestion tank 1 so that the volume of the sludge can be reduced.</p> |
