多段型高温UASBリアクターによる焼酎蒸留粕液画分の高速メタン発酵処理

抄録

A long-term continuous flow experiment was conducted to investigate the process performance of a thermophilic multi-staged UASB (MS-UASB) reactor for treatment of liquid fraction of an alcohol (Shouchu) distillery wastewater. A demonstration scale MS-UASB reactor having a working volume of 2.5m³ was operated at 55°C for a period of over 400 days.
Even though Shouchu distillery wastewater is a typical seasonal campaign wastewater, the process shows superior capability in re-starting up. The reactor steadily allowed a significant high COD loading rate of 60kg COD·Em^-3·Ed^-1, which is equivalent to the influent strength of 10, 000-20, 000mg COD·EL^-1 at an HRT of only 4-8h, keeping COD removal of above 80%. Methane gas concentration in the biogas was about 70-80% over the experimental period. A linear relationship (R²=0.99, 0.97) was found between removed COD and methane production (as a COD conversion value) in Phase 1 and Phase 2. The methane conversion ratio during continuous run with barley-made (Phase1) and sweet potatomade (Phase2) Shouchu wastewater were 95% and 91%, respectively.