3.4. Initial COD and BOD concentration
The effect of initial COD and BOD concentration of the
wastewater solution on the percentage COD and BOD
reduction by CAC and MAC is shown in Fig. 5. The percentage
COD and BOD reduction with MAC and CAC
was found to increase with increase in the initial COD
and BOD concentration, and after reaching to saturation
levels, it was decreasing. The rate of adsorption increased
because of the increasing driving force. But at 1100 mg/l
of initial COD concentration and 500 mg/l of initial BOD
concentration, the curves reached saturation point. It was
expected due to the saturation of adsorbent sites and hence
the ratios of the initial number of adsorbate molecules to
the available adsorption sites of the adsorbent diminish
accordingly.