METHOD AND APPARATUS FOR TREATING ORGANIC WASTEWATER

摘要

PROBLEM TO BE SOLVED: To economically reduce the generation amt. of excessive sludge at a time of the purification of org. wastewater by biological treatment. SOLUTION: In a treatment method of org. wastewater wherein org. wastewater 4 is biologically treated in a biological treatment tank 5 and the treated liquid 6 is subjected to solid-liquid separation treatment to discharge separated water as treated water 8 while returning separated sludge 9 to the biological treatment tank 5, a part or whole of the sludge from the biological treatment tank 5 is supplied to a heating container 13 to be heated for a stagnation time of 30 sea-20 min at 80-250 deg.C and the sludge in a pressurized state is discharged out of the heating container 13 to be crushed before returned to the biological treatment tank 5.