| 摘要 |
PROBLEM TO BE SOLVED: To provide a sludge treatment system capable of being used as an improvement facility useful for existing treatment equipment, and a sludge treatment method capable of suppressing rise in fuel cost.SOLUTION: A method comprises: a dehydration step STP1 of raw sludge A; a methane fermentation step STP3 of subjecting slurry sludge C obtained by adding water to dehydration sludge B to methane fermentation, thereby obtaining digestive sludge D; a step STP4 of separating the digestive sludge D into first digestive sludge D1 and second digestive sludge D2; a decompression and deaeration step STP5 for the first digestive sludge D1; a step STP6 of forming a vacuum state with high-temperature vapor F; a step STP7 of returning concentrated digestive sludge with the high-temperature vapor to the methane fermentation step STP3; and a dehydration and separation step STP8 of separating the second digestive sludge D2 into digestive dehydration sludge G and sludge separation liquid H. Alternatively, a method comprises: a decompression and deaeration step STP5 for the digestive sludge derived from the methane fermentation; a step of branching mixed phase fluid E obtained in the vacuum state with high-temperature vapor; a step of returning branched first mixed phase fluid to the methane fermentation step; and a step of returning second mixed phase fluid to the dehydration and separation step.SELECTED DRAWING: Figure 1 |
