The adsorption of MB at low initial concentration (50–80 mg/L)
reached equilibrium in less than 30 min, while at high initial MB
concentration (110–360 mg/L), the time necessary to reach equilibrium was 120 min. However, the experimental data were measured
at 180 min to be sure that full equilibrium was attained. Data on
the adsorption kinetics of MB by various adsorbents have shown
different ranges of adsorption rates. For example, the equilibrium
times reported for the adsorption of MB were 150 and 90 min for the
adsorption of MB on fallen phoenix tree’s leaves [29] and marine
seaweed (C. racemosa var. cylindracea) [27], respectively.