Research Article α and γ Alumina Spheres for Azo Dye (Allura Red) Removal from Aqueous Media Jonatan Torres-Pérez , 1 Nahum Medellín-Castillo , 2 and Simón Yobanny Reyes-López 3 1 Laboratorio de Transferencia y Degradación de Contaminantes, Instituto de Ciencias Biomédicas, Departamento de Ciencias Químico Biológicas, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente del Pronaf y Estocolmo s/n, Zona Pronaf, Ciudad Juárez, Chihuahua C.P. 32310, Mexico 2 Centro de Investigación y Estudios de Posgrado, Facultad de Ingeniería, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava No. 8, San Luis Potosí SLP 78210, Mexico 3 Laboratorio de Materiales Híbridos Nanoestructurados, Instituto de Ciencias Biomédicas, Departamento de Ciencias Químico Biológicas, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente del Pronaf y Estocolmo s/n, Zona Pronaf, Ciudad Juárez, Chihuahua C.P. 32310, Mexico Correspondence should be addressed to Jonatan Torres-Pérez; jonatan.torres@uacj.mx Received 16 March 2022; Revised 8 April 2022; Accepted 13 April 2022; Published 4 May 2022 Academic Editor: Anjani Ravi Kiran Gollakota Copyright © 2022 Jonatan Torres-Pérez et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Allura red or Red 40 (R40) is a dye widely used in the food, textile, and pharmaceutical industries; it is considered dangerous because it is soluble in water, and it has high toxicity and resistance to natural degradation. Several advanced wastewater treatments have been shown to be effective for R40 removal but some of them present disadvantages such as by-products obtention, high energy consumption, and high cost of the reactants used in the removal process. In the present work, α- Alumina (Alu) and γ-Alu spheres were synthesized by the encapsulation method. The prepared spheres were characterized by FT-IR, XRD, SEM/EDS, and S BET , and it was determined the presence of only inorganic bonds from ceramic material, and the amorphous alumina was observed in spheres with a smooth and uniform surface and with pores. R40 adsorption kinetics and isotherms were performed, as well as material regeneration for consequent sorption cycles. Sorption tests for R40 removal were carried out under different conditions of initial concentration, pH value, and the presence of interfering ions. The maximal sorption capacity of the synthetized α- and γ-Alu spheres were situated between 0.1765 and 18.9865 mg/g. Different kinetic and isothermal equations were applied and finally, the experimental data was described by Elovich and Freundlich models. The γ-Alu spheres after five heat treatment regeneration cycles showed stable behavior and potential re-use in new sorption processes with R40 removal >97.7% at pH 3 and >85.6% at C 0 =10 mg/L. The obtained results showed that the γ-Alu spheres are novel, alternative, and sustainable synthesized materials for the advanced treatment of wastewater by adsorption process for the removal of Allura red azo dye in aqueous media. 1. Introduction Azo dyes are the largest group of synthetic organic dyes, and most of the colored molecules are used in the textile and food industry. Large amounts of dyes are disposed into the sewer system, so the elimination from wastewater presents a greater challenge than the treatment of other organic and inorganic compounds that are degraded by conventional treatments. Azo dyes are the most used synthetic organic compounds to give color to a great variety of commercial products and these kinds of dyes have the particularity to contain one or more azo groups (N=N). One of the most popular azo dyes used around the world is Allura Red (R40) and it has been proved in previous studies that it is carcinogenic and mutagenic [1]. Therefore, there is an urgency to develop effective methods for the advanced Hindawi Adsorption Science & Technology Volume 2022, Article ID 3786561, 14 pages https://doi.org/10.1155/2022/3786561