Synthesis and characterization of metal oxide dopped beaded sugarcane bagasse fly ash for direct red 28 dye removal

The direct red 28 (DR28) dye discharging into the water body creates toxicity to aquatic organisms because of its aromatic structure with difficult degradation and accumulation in the organisms, so DR28 dye-contaminated wastewater is required to be treat before release. This study aimed to synthesize and characterize sugarcane bagasse fly ash beads (SBFB), sugarcane bagasse fly ash beads doped with titanium dioxide (SBFBT), aluminum oxide (SBFBA), zinc oxide (SBFBZ), and magnesium oxide (SBFBM) for removing DR28 dye, and their DR28 dye removal efficiencies were studied by batch experiments, effect of ionic strength, adsorption isotherms, kinetics, thermodynamic studies, and desorption experiments. SBFBM had higher surface area and pore volume than others. They were rough surfaces with irregular structures and consisted of carbon, oxygen, silica, calcium, chloride, sodium, Si-OH, C = O, T - O - T (T = Al or Si), C - O - C, and Si - H. They could remove DR28 dye by more than 82%, whereas SBFBM demonstrated the highest DR28 dye removal efficiency at 98.31%. The ionic strength had little effect on their DR28 dye adsorptions. They corresponded to Freundlich model except for SBFB, and they corresponded to pseudo-second-order kinetic model. They were favorable DR28 dye adsorption with increasing temperatures, and they could reuse more than 5 cycles. (c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

This study synthesized and characterized sugarcane bagasse fly ash beads with various dopants for the removal of DR28 dye. Among them, SBFBM doped with magnesium oxide demonstrated the highest removal efficiency at 98.31%. The adsorption of the beads followed the Freundlich model and pseudo-second-order kinetic model. Increasing temperatures favored the adsorption, and the beads could be reused for multiple cycles.