A STUDY OF THE OPERATION OF MESOPHILIC AND THERMOPHILIC ANAEROBIC FILTERS TREATING A SYNTHETIC COFFEE WASTE

Two anaerobic filters, operated at 37-degrees-C and 55-degrees-C with a synthetic wastewater made from a coffee-bean extract, were used to s tudy the operation of mesophilic and thermophilic digesters. The data were also compared with the performances which had been achieved when the feed used was based on (instant) soluble coffee. The results showe d that the mesophilic filter gave a performance which was comparable t o that achieved with the instant-coffee feed. However, the thermophili c filter exhibited an appreciable degree of instability suggesting tha t the coffee-bean extract contained some component (or combination of components) which had an inhibitory effect on anaerobic processes in t he thermophilic temperature range.