SCUM CRUSHING TYPE ANAEROBIC BIOREACTOR

PURPOSE:To make treatment of scum easy by providing a sludge return path which communicates with both the bottom part of a scum stripper and an anaerobic reaction cylinder and crushing scum by shock at a time when scum falls to the aperture of the scum stripper. CONSTITUTION:Inflow water 2 fed near to the lower end of an anaerobic reaction cylinder 1 is made to an upward flow and raised in a sludge bed 20. When slow agitation is performed by an agitator 4, raw water is brought into contact with anaerobic sludge and decomposing reaction is promoted. The gas being a reaction product is stuck on one part of anaerobic sludge as gas foams according to progress of decomposing reaction and gas sticking sludge 21a is formed and raised to form a sludge ppt. part. Large parts of gas sticking sludge 21a are separated from gas foams and settled as anaerobic sludge to maintain sludge and blanket of the sludge bed 20. Scum 30 falls through a falling port 31 and is crushed. Thereby scum can be crushed and energy consumption can be reduced.