The percentage of COD and BOD removal increased from 93% to
97% and 98% to 99%, respectively, with the increase of OLR, and both
reached the maximum level at OLR of 3.1 kg COD/m3 day and
0.29 kg BOD/m3 day, respectively. This result shows similar trend
with the typical plot of the Monod equation in which the specific
growth rate of the microorganisms rises as the substrate concentration is increased and until it approaches a maximum
point (Leslie Grady et al., 1999). In addition, the result suggests that
increasing OLR does not adversely affect the performance of SBR;
conversely, increasing OLR stimulates the activity of microorganism
and enhances the growth of aerobic culture by providing more
organic substance.