SVI is one of the important parameters to assess the stability of
sludge in any aerobic suspended growth system. An SVI of 150 mg/L
is often considered to be the dividing line between good (SVI < 150)
and poor (SVI gt; 150) settling sludge (Leslie Grady et al., 1999). In
this study, the sludge exhibited good settling properties with
average SVI of 65 as shown in Table 4. Besides, the effluent COD and
BOD are relatively stable ranging from 724 to 1290 mg/l and
31e124 mg/L, respectively. Generally, the digested effluents have
successfully met the discharge limit, with certain occasions where
the treated effluents failed to meet the discharge limit. Therefore,
further improvements on the performance of the SBR are essential
to produce a consistent treated effluent quality which meets the
discharge limit in any condition.