SEWAGE TREATING DEVICE, DEHYDRATION TREATMENT OF SLUDGE, SLUDGE DEHYDRATED CAKE AND FERTILIZER

摘要

PROBLEM TO BE SOLVED: To improve the environment of treating equipment (an initial settling tank, an aeration tank, a discharged water passage and a storage tank) of a savage treating device by effectively utilizing a drying process of mint in a sludge dehydrating method, sludge dehydrated cake and fertilizer or the like. SOLUTION: The mint (powder of Japanese mint 21 and powder of western mint 22) is dried in a drying chamber 18. Air absorbing the mint 21, 22 component volatilized in the drying is supplied to each of the initial settling tank 4, an aeration tank 6, the discharged water passage 11 and a storage tank 5 by a blower 23. In a dehydrator 17, a mixed sludge 24 formed by mixing stored sludge 16 with the powder of the mint 21, 22 is dehydrated to generate the sludge dehydrated cake 25 and separated liquid 26. The separated liquid 26 is returned to a concentrating tank 13. The sludge dehydrated cake 25 contains the powder of Japanese mint 21 and the powder of western mint 22. The fertilizer or the like 27 is produced from the sludge dehydrated cake 25.