Development of an eco-friendly and low-cost adsorbent from Red-Angico (Anadenanthera macrocarpa (Benth.) Brenan) residues: Application for the removal of methylene blue

• Published in: Next materials Vol. 6; p. 100331
• Main Authors: Rodrigues, Tereza Longaray, Guterres, Fernanda Pedroso, da Silva, Elenara Oliveira, de Araújo, Emanuelle Burato, da Rosa, Gabriela Silveira, de Almeida, André Ricardo Felkl
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2025
• Subjects: Adsorption; Biomass; Effluent; Impregnation; Impregnation; Biomass; Adsorption; Effluent
• ISSN: 2949-8228; 2949-8228
• DOI: 10.1016/j.nxmate.2024.100331

The present paper aimed to develop an eco-friendly and low-cost adsorbent material from Red-angico residues by its chemical activation and evaluation on cationic dye adsorption. It was carried out the characterization of materials produced in natura, NaOH-impregnated and H3PO4-impregnated, as well as adsorption studies of methylene blue. It was possible to observe that the materials produced presented characteristics which play an important role as adsorbent material. Impregnation resulted in a reduction in particle size, changes in porosity and bulk density, and decreased moisture content. The NaOH-impregnated material showed reduced ash content and increased volatile matter, which enhanced its adsorption properties. For the H3PO4-impregnated material, volatile matted decreased, and fixed carbon increased. Thermogravimetric analysis revealed that both treatments led to the degradation of lignocellulosic compounds, with H3PO4 causing more intense degradation. Regarding the kinetic study, it was observed that pseudo-second order model showed the best fit of experimental data, and equilibrium was reached in less than 40 min, been mainly controlled by convective adsorption mechanism. About the isotherm study it was observed an increase on maximum adsorption capacity of 17.79–55.34 mg.g−1 after the impregnation with sodium hydroxide. Therefore, it was possible to observe that the procedures employed allowed the reuse of Red-Angico residues which has led to obtaining of interesting adsorbent materials.