METHOD AND SYSTEM OF SLUDGE CONCENTRATION

PROBLEM TO BE SOLVED: To provide a sludge concentration method for achieving a sufficient sludge concentration effect and facilitating the discharge of concentrated sludge while the sludge is continuously concentrated at a high speed with structure of a device to be simplified and downsized, and to provide a sludge concentration system.SOLUTION: The sludge concentration method and the sludge concentration system include: a solid/liquid separation step for horizontally or almost horizontally irrigating a crude sludge under atmospheric or reduced pressure to separate the sludge into a separated sludge and a supernatant liquor as solid/liquid separation; and in the downstream of the solid/liquid separation step, a flotation thickening step for combining the separated sludge with a bubbling gas under reduced pressure and vertically or almost vertically floating the separated sludge to thicken the same for obtaining a floated sludge.