Adsorption of Organic Dye onto Mesoporous Aluminosilica Monoliths: Equilibrium, Kinetic and Thermodynamic Studies

Abstract

In the present study, high order aluminosilica monolith (HOASM) composite with high alumina content (Si/Al=1.5) was fabricated through a reproducible, simple, and one-pot synthesis strategy. Achieved was a realistic control over the cubic Ia3d geometry of aluminosilica monoliths using microemulsion phases of copolymer P123 as soft templates. The geometrical and textural pore structures of the HOASM composite were characterized with various tools of EDX, FESEM, HRTEM, XRD and N2 isotherms. The quantity of aluminum species present in the walls of the silica pore structure has a substantial impact on the acidity of nanoadsorbent. The HOASM nanoadsorbent was used as a removal of Crystal violet (CV) from wastewater. A major contributing factor to the improvement of the coverage of the HOASM composite adsorbent surfaces were the multi-directional pores (3D) and the mesostructural geometries of the aluminosilica adsorbent. The performance factors like temperature, adsorbent dose, concentration, pH, and contact period, were all examined to evaluate the CV dye adsorption. It was found that, at a pH of 8, the greatest CV dye adsorption on HOASM composite was achieved. The optimal concentration for CV adsorption was 1.5 mmol/g, and the adsorption isotherm matched the Langmuir model, though the adsorption kinetics were matched to a pseudo-second-order model. Thermodynamic experiments have shown that the CV dye adsorption on the HOASM composite is endothermic and spontaneous.