TWO-PHASE ANAEROBIC DIGESTION FOR BIOGAS PRODUCTION FROM DAIRY EFFLUENT---CSTR AND ABR IN SERIES

摘要

Anaerobic digestion of low-strength dairy waste water has been used for the production of biogas. A two-phase pilot scale process had been established within 90 d using a 1 m3 continuous stirred tank reactor (CSTR) and a 200 l anaerobic baffled reactor (ABR) in series. The system was fed at constant retention time of 1.6 d and with changing feed strengths resulting in various organic loading rates between 1.25-4.50 g/(l d). The average COD removal was 82 % with a biogas yield of 0.26 l/gCOD. The combination of CSTR and ABR overcame the disadvantages of both reactor types. By further optimization the chosen system is able to replace conventional waste water treatment system used nowadays.