Adsorbents for The Removal of Tartrazine Dye From Aqueous Solutions: A Review

This article summarizes the up-to-date published literature regarding the removal of tartrazine (TZ) dye from aqueous solutions by the adsorption method. Adsorption is one of the physicochemical processes employed for dye removal because of its simplicity in operational design and economic requirements when compared to other techniques, such as chemical and biological methods. Based on their chemical composition, the adsorbents were classified into four groups: 1) Polymers, resins and nanoparticles; 2) activated carbon, substances of natural origin; 3) clays/modified clay and sand; 4) agricultural waste/by-products and others. Activated carbon, polymers and nanoparticles obtained from diverse bio-sorbents emerged as the dominant adsorbents for tartrazine (TZ) removal due to their notable adsorption capacities (reaching up to 584 mg/g), high surface areas (reaching up to 425 m(2)/g) and varied pore diameters spanning from 35.4 to 150 nm. These materials exhibit superior efficacy in TZ removal, demonstrating effective adsorption within contact times ranging from 5 to 1440 minutes. Adsorbents from plant and animal origins such as hen feather, alligator weed and spirulina biomass exhibit high dye removal capacity. Clay/modified clay and sand materials have attracted the attention of researchers due to their abundance and low cost. Agricultural wastes were utilized as adsorbents as they showed good results in removing TZ and represent, thus, a potential to manage waste materials successfully.