Experimental design data for the zinc ions adsorption based on mesoporous modified chitosan using central composite design method.

In the present study, new generation of silica-based mesoporous adsorbents were introduced for the removal of heavy metals with the aim of developing new adsorption technologies in water treatment. The magnetic nanoadsorbent, prepared by modification of SBA-15 with [3-(2-Aminoethylamino) propyl] trimethoxysilane (AEAPTMS)-functionalized chitosan, was applied for the removal of Zn2+ from aqueous solution. The synthesized Fe2 O3 @SBA-15-CS-AEAPTMS nanoadsorbent was thoroughly characterized using XRD, TEM, FTIR and BET analysis. In order to determine the optimum condition of Zn2+ adsorption on Fe2 O3 @SBA-15-CS-AEAPTMS (3 ml), the experiments were performed based on central composite design in a response surface methodology method. The obtained results were further studied using adsorption kinetic, isotherm and thermodynamic relations which revealed that Zn2+ adsorption was spontaneous and endothermic with enhanced adsorption efficiency achieved for higher contents of functional groups. In addition, according to the results, the adsorption process was best conformed to Langmuir isotherm (with R2  > 0.99 and qmax  = 107.21 mg g-1 ) and pseudo second-order kinetic model (with R2  > 0.999). The values of standard entropy (DS°) and activation energy (Ea ) reduced as the initial concentration was increased and the dominant mechanism was found to be chemisorption.