Characterization of Rice Husk-Based Adsorbent for Iodine and Methylene Blue Solutions Cadme-Arévalo, María Lorena Campisi Cadme, Raisha Lorena Arreaga Cadme, Thais Sarah Villamar-Torres, Ronald Oswaldo Fernández González, Javier Benavente Herrera, José Geijo López, Alda Aransiola, Sesan Abiodun Maddela, Naga Raju Rice husk Adsorbent microstructure Dye removal This study focused on the comprehensive characterization of the adsorbent obtained from rice husk, which was selected for its high adsorption capacity in iodine solution (IS) and methylene blue solution (MBS). This was achieved with adsorbents prepared by a combined treatment involving calcium carbonate prior to carbonization and activation with phosphoric acid. Characterization was performed using advanced techniques, such as scanning electron microscopy (SEM), atomic force microscopy (AFM), laser light diffraction and energy-dispersive X-ray spectroscopy (EDS), which allowed for the evaluation of the adsorbent’s microstructure and composition. The results revealed a complex structure of the adsorbents with interconnected pores, which facilitates efficient adsorption in IS and MBS and the standard indicators to evaluate adsorption capacity. The novelty of this study lies in the application of advanced characterization techniques to optimize the adsorbent properties and understand how preparation conditions affect the adsorbent’s microstructure. The characterized adsorbent materials in this study presented great potential for applications in water treatment and industrial processes, offering an economical and environmentally sustainable solution. Promoting the use of rice husks in the production of adsorbents contributes to the circular economy, reducing production costs and environmental pollution. The results suggested that these materials are effective in the removal of pollutants, which make them relevant for practical applications in water and soil bioremediation. 2025-10-06T11:25:00Z 2025-10-06T11:25:00Z 2025-08-28 journal article Cadme Arévalo, M.L.; Campisi Cadme, R.L.; Arreaga Cadme, T.S.; Villamar-Torres, R.O.; Fernández González, J.; Benavente Herrera, J.; Geijo López, A.; Aransiola, S.A.; Maddela, N.R. Characterization of Rice Husk-Based Adsorbent for Iodine and Methylene Blue Solutions. Processes 2025, 13, 2748. https://doi.org/10.3390/pr13092748 https://hdl.handle.net/10481/106839 10.3390/pr13092748 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional MDPI