where Co (mg L1) is the initial concentration of the solute in
aqueous solution, Ct (mg L1) is the solute concentration in aqueous
phase at time t, V (L) is the solution volume and m (g) is the
mass of the adsorbent. For experiments studying the effect of pH
on adsorption, 50 mL of MO solution with initial concentration
of 500 mg L1 was used. The pH was adjusted by addition of
0.1 M HCl or NaOH solution and the contact time was set at 5 h.