Adsorptive characterization of a pure magadiite and an organic modified magadiite on removal of methylene blue from related aqueous solution

Abstract

Organic modified magadiite (MAG-CTAB-KH550) was used as an adsorbent to study its adsorption capacity on methylene blue (MB) in this research. MAG-CTAB-KH550 was synthesized via ion-exchange method in the presence of pristine magadiite (MAG), cetyltrimethylammonium-Bromide (CTAB) and γ-aminopropyltriethoxysilane (KH550) in aqueous solution. The formation of MAG-CTAB-KH550 was characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses. The effect(s) of adsorbent dosage, adsorption time and the pH value of the solution were investigated to characterize the performance and mechanism by MAG for removing the MB from aqueous solutions. It was found that the maximum adsorption capacity of MAG-CTAB-KH550 on MB was 96.60 mg/g and it was 22.9% higher than adsorption capacity of MAG while the adsorption parameters were set to the maximum adsorption time at 60 min as initial concentration of MB with 100 mg/L, sorbents mass with 1 g/L, pH with 12, and temperature with 298 K. In this research study, the adsorption capacity was increased slowly at pH < 4.0, quickly at pH range 4–9, reached at a peak, and then balanced at pH > 9 while the economical amount of sorbents was 1 g/L and the maximum adsorption capacity was reached at 60 min. The behavior of adsorption kinetics was followed by the pseudo-second-order kinetic adsorption model; moreover, the adsorption isotherms were followed the Langmuir predominantly for MAG and MAG-CTAB-KH550 on MB. In addition, the results also showed that the MAG-CTAB-KH550 was performed better adsorption capacity and removal rate on MB than pure MAG.