JPS6456192A - Septic tank - Google Patents

Abstract

PURPOSE:To decrease the flow transfer of solid matter into a 2nd chamber of a cleaning tank provided with an anaerobic treatment chamber consisting of the 1st chamber and 2nd chamber and an aerobic treatment chamber by providing partition walls between the 1st chamber and the 2nd chamber and between the 2nd chamber and the aerobic treatment chamber and providing a flow transfer pipe to the 1st chamber. CONSTITUTION:The sewage flowing from an inflow port 4 into the 1st chamber a1 receives anaerobic decomposition during the passage through a 1st anaerobic filter bed 5 and the solid matter in the sewage sticks to the filter media and similarly receives the anaerobic decomposition. After the coarse solid matter of this sewage is settled in the 1st chamber a1, the sewage is transferred from the 1st flow transfer pipe 10 to the upper part of the 2nd anaerobic filter bed 9 of the 2nd chamber a2 where the sewage passes from above to below and again receives the anaerobic decomposition. The sewage is transferred to the aerobic treatment chamber a3 where the sewage is subjected aerobic decomposition and is cleaned. Namely, the solid matter in the sewage is settled in the bottom of the 1st chamber a1, but since the 1st chamber a1 and the 2nd chamber a2 is completely partitioned by the partition wall 1, the flow transfer of the sewage is executed only by the 1st flow transfer pipe 10 and the flow transfer of the solid matter to the 2nd chamber a2 is extremely little.