SYNTHESIS, PHYSICAL-CHEMICAL AND ADSORPTION PROPERTIES OF Fe/Al-BENTONITES

Fe/Al bentonites were synthesized by modifying bentonite clay with iron and aluminum polyoxocomplexes at different iron and aluminum molar ratios. The chemical composition was determined, and the structure and physicochemical properties of the materials were studied using a set of methods (scanning electron microscopy with an energy-dispersive microanalysis system, X-ray phase analysis, low-temperature nitrogen adsorption). Modification of bentonite clay with Fe/Al complexes resulted in an increase in the iron and aluminum content, an increase in the interplanar distance and specific surface area, and a change in the morphology of bentonite clay particles. The iron and aluminum content in the obtained materials was 7.57-14.74% and 10.84-13.45%, respectively. The specific surface area of the materials was 108-137 m2/g. The Fe/Al bentonite particles were presented as loose microaggregates of various shapes and sizes with a greater number of pores compared to bentonite clay. The adsorption properties of the materials were tested in the adsorption of anthraquinone dye Acid Bright Blue, which is widely used in the textile industry and is found in industrial wastewater. The results showed that the adsorption capacity of the modified materials for the dye exceeded the adsorption capacity of bentonite clay by 8-13 times, which is due to the increase in the number of adsorption centers (Fe/Al)-OH and the specific surface. The adsorption of the dye on the modified materials was 10.5-11.3 mg/g at pH 6.0 and increased to 21.8-28.3 mg/g at pH 4.0. The obtained materials can be used in the purification of textile industry wastewater from anthraquinone dyes. For citation: Badmaeva S.V., Khankhasaeva S.Ts., Ukhinova M.V. Synthesis, physical-chemical and adsorption properties of Fe/Al-bentonites. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 10. P. 87-94. DOI: 10.6060/ivkkt.20256810.7209.