SOIL TREATMENT APPARATUS OF SEWAGE

摘要

PROBLEM TO BE SOLVED: To prevent reduced treatment capacity by providing the apparatus with a perforated sewage pipe which drains part of the sewage flowing therein and percolates and infiltrates the sewage into soil and a sludge removal pipe which removes the residual sludge contg. the hardly decomposable org. matter and BOD sludge converted matter in the perforated sludge pipe to the outside. SOLUTION: A plastic filter medium 32 is arranged in the sewage pipe 31 and the sewage pipe 31 is bored with holes to drain part of the sewage passing through the pipe and to receive the sewage with the filter medium 21. The sewage is subjected to a purification treatment by the biological membranes of the aerobic microorganisms formed by the filter medium 32. The filter medium 32 is circumferentially enclosed by a nonwoven fabric and percolates and infiltrates the drained sewage into the soil 39. The sludge removal pipe 35 is arranged in the sewage pipe 31. The sludge removal pipe 35 is connected to the sewage pipe 31 by a connecting pipe 36. One end of a sludge return pipe 37 is connected to the sludge removal pipe 35 and a biochemical pretreatment vessel 10 is connected to the other end of the sludge return pipe 37. The residual sludge is removed from the sludge removal pipe 35 and is returned to the biochemical pretreatment vessel 10. As a result, the degradation in the purification capacity may be prevented.