RESULTS AND DISCUSSION
The reactor during this study was monitored on a
daily basis for four parameters, i.e., temperature, pH,
DO, and mixed liquor suspended solids (MLSS). The
first three parameters have a profound effect on biological
growth and efficiency of biological treatment
system11 and the fourth parameter, i.e., MLSS was
used to determine the kinetic coefficients. The values
of these parameters are presented in Fig. 2.
The temperature of the reactor remained in a
range of 16–24 °C. All the processes of growth are
dependent on chemical reactions, and the temperature
influences the rate of these chemical reactions. Thus
the rate of microbial growth as well as total amount of
growth can be affected by temperature.
The pH of the reactor during the study remained
between 7.0 and 8.0 for most of the research period.
Extremes of pH are fatal for most bacteria. The
bacteria grow best when the pH is slightly on the
acidic side. The optimum range for bacterial growth
generally lies between 6.5 and 7.513. Activated sludge
and aerated lagoons could be successfully operated
when the pH was between 9 and 10.511.
DO of the reactor remained between 3 mg/l and
4.2 mg/l for most of the study period. This value
was ideal for the biological treatment systems working
under aerobic conditions. The values of DO for the
present study were above the minimum level of 2 mg/l
which has been widely reported in the literature11.
The treatment efficiency of the reactor in terms
of BOD5 and COD removal was studied at different
detention times. It was noted that the process efficiency
improved with increase in detention times.
Thus the results indicate that the BOD and COD of
the effluent at 5 days detention time were 66 mg