| 摘要 |
In order to sanitise wet sludge, originating from a sewage treatment plant, perfectly without supply of external heat, the fresh sludge having a dry matter content of at least 4% by volume is first passed into a wet sludge aeration tank (2). In the latter, the sludge situated therein is aerated with an oxygen-containing gas or pure oxygen in such a manner that, as a consequence of the biological conversion process, temperatures in the region of 45 to 80 DEG C occur in the sludge and an aerobic partial stabilisation takes place. The sludge thus pretreated is withdrawn, after sanitation is completed, from the wet sludge aeration tank (2) via the line (7) and is passed at a temperature of at least 40 DEG C into a digestion tank (8). In the latter, with methane gas formation, an anaerobic complete stabilisation proceeds, after the completion of which, the sludge treated in this manner is dewatered to a dry matter content of at least 6% by volume by take-off of turbid water via the take-off line (10), and the sludge is taken off from the digestion tank (8) via the line (11). <IMAGE>
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