OPERATION OF A NOVEL ANAEROBIC BIOFILTER FOR TREATING FOOD-PROCESSINGWASTE-WATER

An anaerobic biofilter was operated with 4500 mg COD/L food-processing waste water, fed at 10 d of hydraulic retention time (HRT). In 45 d a fter seeding, established biofilms were dominated by dense layers of M ethanococcus-like and Mefhanothrix-like cells. The average COD and gre ase removal efficiencies were 85 and 53%, respectively, when the HRT w as decreased stepwise to 1.5 d. Immobilized biofilms enabled the biofi lter to be started up easily, to have stable treatment performance, an d to recover rapidly from shock loadings and process failure.