4. Conclusions
The application of micro-aeration during pre-stage
showed an equivocal result on hydrolysis/acidiWcation
enhancement. Flushing for short duration of Wve days with
lesser volume of water (29.3 l/kg TS) was found beneWcial to
partly remove the organic matter from waste bed in preparation
for methane phase. Hydrolysis yield of 140 g/kg
TS which is equivalent to 30% of C from the waste bed
was removed in leachate form and acidiWcation yield of
180 gVFA/kg TS were obtained. The importance of leachate
percolation during methane phase was recognized to
enhance biogas production. Nevertheless, micro-aeration
during pre-stage may have a positive eVect in methanogenesis
since an active methane phase was reached early compared
to other reactors without micro-aeration. This might
have resulted in better hydrolysis/acidiWcation during the
start-up of methanization period providing substrate for
methanogens. Thus, micro-aeration exhibits an equivocal
eVect in terms of enhancing anaerobic digestion process
and this needs further investigation. The actual methane
yield of waste (260 l CH4/kg VS) was compared with the
result of BMP test (300 l CH4/kg VS), it revealed that 75%
process eYciency can be obtained in this process.