| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an anaerobic treatment tank capable of obtaining clean treated water and simple in structure, and an organic wastewater treatment apparatus using the anaerobic treatment tank. SOLUTION: Organic wastewater flows in the lower part of the anaerobic treatment tank A and treated water is discharged from the upper part of the treatment tank A. In order to subject organic wastewater to digestion treatment, an lower bed 6a comprising anaerobic contact filter media, which are arranged laterally at a constant interval in a form of a plurality of lumps or aggregates having an expanse in a lateral direction and arranged over a plurality of stages so as to be partially overlapped up and down at a constant interval, and an upper layer 6c comprising a filter medium having a large specific surface area and having specific gravity lower than that of a treated liquid are provided in the treatment tank A. Further, an intermediate layer 6b filled with an arbitrary contact filter medium may be provided. The sludge formed in an aerobic treatment tank B is returned to the anaerobic treatment tank A and the sludge after digestion treatment is discharged to the aerobic treatment tank B. The upper space of the aerobic treatment tank B may be equipped with exhaust ducts 21 and 22 so as to be connected to a deodorizing apparatus 30 directly or through the upper space of the anaerobic treatment tank A.</p> |
