Solution pH affects the properties of both adsor-bate and
adsorbent and is therefore a very important parameter affecting
adsorption process in aqueous solutions. The effect of pH is
attributed to the electrostatic interaction between the adsorbate
molecule and the adsorbent surface. The effect of initial solution
pH on adsorption of 2,4-D by CCAC was studied in the pH range
3–11 and the result is illustrated in Fig. 7. The Figure depicts the
decrease in adsorption capacity of 2,4-D with increase in initial pH
of the solution.