多段型UASBによる高濃度脂質・固形物含有パームオイル圧搾廃液 (POME) の高速処理と保持汚泥の変遷

抄録

A multi-staged UASB reactor was applied to Palm Oil Mill Effluent (POME) which contains high strength of particulate organics and lipid. Two sets of laboratory-scale reactor were operated for 15 months in parallel at different temperature; 55°C and 35°C. The thermophilic reactor accommodated a COD loading rate of 25kg COD·m^-3-d^-1 with COD removal of 73.9±9.6, while the mesophilic reactor achieved 10kg COD·m^-3·d^-1 with COD removal of 84.9±5.4. Throughout the whole duration the methane conversion (defined by methane COD recovered per COD removed) was higher by 14% by the thermophilic reactor than by the mesophilic reactor. Both reactors performed satisfactory lipid removals of above 80%. The extent of accumulation of un-degraded orgnic solids in the mesophilic reactor was more significant rather than in the thermophilic reactor. Both reactors eventually exhibited stable reactor performance over 7 months at each maximum organic loading rate, showing no sign of process failure throughout the period.