Ultrasound-assisted synthesis of a new material based on MgCoAl-LDH: Characterization and optimization of sorption for progressive treatment of water

This study had two goals: the first one was the synthesis and detailed characterization of the new layered double hydroxide based on Mg, Co, and Al; the second one was defining the optimal conditions for application of material for removal of the anthraquinone dye RB19 from water. The structure and characteristic functional groups of material were examined by the XRD and FTIR methods. BET surface area of the synthesized material, named MgCoAl-CO3-LDH, was 47.67 m(2)g(-1), while the BJH adsorption average pore diameter was 14.65 nm. SEM micrographs and EDX analysis showed that the morphology and structure of MgCoAl-CO3-LDH remained unchanged after removing RB19. The optimal parameters for removal of RB19 were pH 4, sorbent dose 0.3 g dm(-3), stirring speed 220 rpm and temperature 10 degrees C. The mechanism of RB19 removal, sorption capacity and nature of sorption process were defined by kinetic, isotherm and thermodynamic analysis. The surface of MgCoAl-CO3-LDH was heterogeneous; the results indicated that the main sorption mechanisms were the physisorption, electrostatic attraction and chemical bonding. The maximum sorption capacity for dye was 367.93 mg g(-1) at 20 degrees C. Delta G(0) values indicated that sorption was thermodynamically favorable and spontaneous. The Delta H-0 value indicated the exothermic nature of sorption. The highly efficient and environmentallyfriently sorbent MgCoAl-CO3-LDH was successfully applied for removal of RB19 from real waters, which indicated a possible wider use of this sorbent for similar anthraquinone dyes removal from contaminated waters. (C) 2022 The Author(s). Published by Elsevier B.V.