| 摘要 |
<p>PURPOSE:To dry and incinerate formed sludge with the saved consumption of energy, by supplying dehydrated cake to a hermetically sealable vessel connected to the ejection side of an aeration blower, and supplying outflow air from said vessel to the step of biotreatment. CONSTITUTION:Sewage 1 is circulated through a primary precipitation basin 2, biotreated in the aeration tank 3 of the step of treatment with activated sludge and then separated into a liquid and solid matter in a final precipitation basin 4 to obtain treated water 5. After crude sludge 6 and excess sludge 7 are concentrated in a sludge-thickening step 8, dehydrativity is improved by the addition of a dehydrating agent, heat treatment, etc. Said sludge is then dehydrated to water content of 50-60% in a mechanical dehydration step 9 to obtain dehydrated cake 10. Said dehydrated cake 10 is supplied to an aerative drying part 15 and aeratively dried with air 13 ejected from an aeration blower 11, while outflow air 16 from the aerative drying part 15 is supplied to the aeration tank 3. The dehydrated cake 10 is dried with the thermal energy of the ejected air 13 to form dried matter 17 having water content of a few %.</p> |
