The
transitional phase (from 2 to 4g VS/l/day) was
typified by signs of a healthy reactor. Methane
production increased steadily to 0.48 l/g VS added
(ABR with two chambers), 0.52 l/g VS added (ABR
with three chambers), 0.59 l/g VS added (ABR with
four chambers), and 0.62 l/g VS added (ABR with
five chambers), whereas methane and CO2 contents
of the gas remained uniform at approximately 65
and 30%, respectively, in all the reactors. The pH
varied from 6.8 to 7.2 throughout the study in all the
reactors. P