| 摘要 |
PROBLEM TO BE SOLVED: To provide a deaeration method and an anaerobic digestion method for pressure flotation concentrated froth capable of completely removing the air bubbles and dissolved gaseous components included in the concentrated froth, and an apparatus for these. SOLUTION: The deaeration method for the froth comprises subjecting the froth discharged from a pressure flotation concentration facility to vacuum deaeration, in which the vacuum deaeration is performed by reducing a vacuum degree down to a range of from -33.3 to -93.3 kPa and the carbon dioxide dissolved in the froth can be reduced down to≤0.59/L. The method for anaerobically digesting the excess sludge produced in a water treatment facility by an activated sludge process is formed as the anaerobic digestion method comprising subjecting the excess sludge to the pressure flotation concentration, subjecting the resultant froth to a vacuum deaeration treatment, discharging the air bubbles and dissolved gaseous components contained in the froth to the outside of the system and subjecting the deaerated sludge to the anearobic digestion treatment. COPYRIGHT: (C)2004,JPO
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