TREATMENT OF SEPARATED SOLUTION FROM DIGESTION TANK

摘要

PURPOSE:To reduce the concn. of the org. substance of return water, by returning the separated solution separated from digested sludge in a digestion tank to a gravitational concn. tank along with the withdrawn sludge from a first sedimentation basin. CONSTITUTION:The separated solution of a digestion tank 15 is charged in a gravitational concn. tank along with the withdrawn sludge 8 from a first sedimentation basin 6. The high concn. separated solution of the digestion tank 15 is diluted to concn. receiving no sedimentation interference by the withdrawn sludge 11 from the first sedimentation basin 4 being the inflow sludge of the gravitational concn. tank 12 and excessive sludge 10. Flocs of sludge are formed so as to be grown on the solids contained in the separated solution as nuclei to promote the solid-liquid separation of the gravitational concn. tank 12. Therefore, the generation amount of digestion gas is increased to promote digestion.