| 摘要 |
<p>PURPOSE:To improve treatment efficiency and to provide high resistance to fluctuations in load in a treating method combining anaerobic and aerobic biological treatments, by using multiple stages of anaerobic filter beds and a contact oxidation tank, and returning the excess sludge in the contact oxidation tank to a contact digesting tank. CONSTITUTION:The waste water from a grit chamber flows from an inflow part 3, past an inflow pipe 5, into the lower part of a contact digesting tank A, where the water passes in the form of upward current in an arrow direction from the lower stages to the upper stages of anaerobic filter beds 6, 6-. During this time, the water contacts the anaerobic living membranes formed in the beds 6 and is thereby purified. The purified waste water flows through a pipe 9 into an aerobic contact oxidation tank B. The water is circulated in the tank B by the circulating flow of the air supplied from an air supply pipe 12 and contacts cyclically with the aerobic living membranes formed in aerobic filter beds 11, whereby the waste water is purified. The purified water is discharged through a pipe 13. The excess sludge formed in the tank B is returned from the bottom end of the tank B through a sludge return pipe 14 fully into the tank A. This sludge is digested and decomposed together with the org. materials in the inflow waste water and settles as digested sludge. The digested sludge is discharged through a discharge pipe 8.</p> |
