Adsorption of Gentian violet dye onto mesoporous aluminosilica monoliths: nanoarchitectonics and application to industrial wastewater

Abstract

ABSTRACT This research demonstrates the ability of cubic Ia3d aluminosilica (CAS) adsorbent prepared using a simple and repeatable one-pot synthesis technique to remove the cationic dye, such as Gentian violet (GV) from aqueous solutions. The prepared CAS adsorbent nanoarchitectonics appeared with 573 m2 g−1 as a BET surface area. The adsorption behaviour of GV on CAS adsorbent was investigated using the thermodynamics, kinetics, and isotherm models. According to the results, the CAS adsorbent indicated a high ability to absorb GV from an aqueous solution, and their kinetic behaviour follows a pseudo-second-order kinetic. In addition, the equilibrium study revealed that the GV adsorption by the CAS adsorbent followed the Langmuir model. Additionally, the outcomes obtained revealed adsorption of GV onto CAS adsorbent was dominated by electrostatic attraction forces, hydrogen bonding, ion-exchange, and pore filling, The maximum adsorption efficiency of GV onto CAS adsorbent was instituted to be 1.36 mmol g−1 (i.e. 554.85 mg g−1). The enthalpy (ΔHo), entropy (ΔGo), and Gibbs free energy (ΔSo) parameters revealed that the extraction of GV dye using CAS adsorbent was endothermic and spontaneous. The synthesised CAS adsorbent shows significant recyclability and characteristics of re-generability up to five adsorption-desorption cycles. As a proof of concept, the performance of the prepared adsorbent was evaluated for laboratory-scale purification of wastewater samples.