Matsumoto et al. (2003) investigated the co-digestion of
swine manure and kitchen garbage, using a continuously
stirred tank reactor (CSTR) at an OLR of 2.47 kg-
VS m3 day1 and HRT of 30 days (far longer than in this
study); specific biogas of 900 L kg1-VS was obtained.
Throughout the experiments, increasing the OLR and
shortening the HRT led to decreased biogas production,
while the developed two-phase anaerobic digestion system
indicated a high-performance at a high OLR and a short
HRT, compared with the conventional ones. The acidification
reactor also served as a buffer tank because the
source materials were fed once a day. Therefore, the twophase
anaerobic digestion system is suitable for practical
use, considering that the discharge and compositions of
the swine manure and garbage fluctuate daily.