Meriam Imane Babaghayou

In this investigation, we studied the removal of two cationic dyes, methyl green MG and malachite green Mc G, by a commercial adsorbent. This adsorbent is a F400 activated carbon with a specific surface area of 1203 m2. g-1, which is expected to be high compared with ordinary adsorbents. Adsorption tests were carried out on both dyes in batch mode. The results show that both kinetics are fast, with equilibrium reached after 20 minutes and 30 minutes respectively for Methyl Green and Malachite Green. The kinetics of both dyes are well adapted to pseudo-second order, and for the intraparticle diffusion model, two lines can be distinguished for each dye, proving the existence of two adsorption steps. The isotherm for this system reveals an L-type shape for both dyes, in line with the classification of Giles & al. so there is little competition for sorption sites between solvent and adsorbate. The adsorption isotherms for methyl green by PAC obeyed the Langmuir, Freundlich and Temkin models, while that for malachite green followed only the Langmuir isotherm, with a much higher maximum amount.