Functionalized magnetic mesoporous palm shell activated carbon for enhanced removal of azo dyes

A novel adsorbent magnesium and silica coated magnetized palm shell activated carbon (MMPAC) was synthesized via hydrothermal process. MMPAC exhibited high adsorption capacity of 369.54 mg L-1 for methylene blue, 528.98 mg L-1 for methyl orange and 257.25 mg L-1 for congo red. MMPAC removed single, double and multiple dyes effectively and the experimental results matched Langmuir isotherm and pseudo second order kinetic models. MMPAC was regenerated and recycled four times using simple technique with no significant drop observed in the adsorption capacity. Thermodynamic parameters revealed that the adsorption is endothermic and spontaneous at room temperature. Pseudo second order kinetic model parameters and intraparticles diffusion of dyes implied that the dominating adsorption mechanism was physical in nature.