ANAEROBIC DIGESTION TREATMENT METHOD AND APPARATUS OF ORGANIC WASTE LIQUID

摘要

PPROBLEM TO BE SOLVED: To provide an anaerobic digestion treatment apparatus of an organic waste liquid which can reduce the amount of organic substances even under a high organic loading without the need of increasing a heating energy or the amount of a flocculant to be used and which enables methane gas to be recovered in an increased amount. PSOLUTION: An organic waste liquid is introduced into a high-temperature digestion tank 1 and subjected to anaerobic digestion treatment at 45-95C. The digested sludge is introduced into a medium-temperature digestion tank 2 and subjected to anaerobic digestion treatment at 25-40C. Part of this digested sludge is removed and concentrated with a solid-liquid separator 3. The concentrated sludge is returned to the medium-temperature digestion tank 2. Part of the digested sludge sent from the medium-temperature digestion tank 2 is modified with a modification device 6 and returned to the high-temperature anaerobic digestion tank 1. Part of digestion sludge from the high-temperature digestion tank 1 is fractionated with a sludge fractionation device 10, sludge having a high ratio of an organic suspension is returned to the high-temperature anaerobic digestion tank 1, and sludge having a low ratio of the organic suspension is discharged outside a system. PCOPYRIGHT: (C)2008,JPO&INPIT