Eriochrome Black T (EBT), a widely utilized azo dye in many industrial operations, is regarded as harmful to man and the environment due to its toxicity and persistence in aquatic biodiversity. Consequently, to minimize its environmental impact, EBT must be efficiently eliminated from the aquatic ecosystem. This review examines a wide spectrum of adsorbents, including natural materials (clays and biomass), synthetic resins, advanced nanostructured systems (carbon nanotubes, nanometals, and nanofibers), and engineered materials such as activated carbons, biochars, hydrogels, covalent organic frameworks, layered double hydroxides, metal–organic frameworks, and composite adsorbents, with emphasis on recent advances in the removal of Eriochrome Black T from aqueous media. The adsorption mechanisms, performance trends, key operational parameters, and regeneration behaviour of these materials are critically analyzed, highlighting the broad variability in reported adsorption capacities across different material classes. The adsorption of EBT was significantly enhanced under acidic conditions, indicating a strong dependence on lower pH media. Improved removal of EBT was associated with higher adsorbent amounts, longer interaction times, greater initial dye levels, and elevated temperatures, all of which contributed to increased adsorption efficiency. The kinetic data for EBT uptake were best explained by the pseudo-second-order model, while the equilibrium adsorption was effectively characterized using both the Freundlich and Langmuir isotherm models. The study highlights the advantages and disadvantages of each material for high-performance adsorbent design. This work aims to provide critical surveys of state-of-the-art developments and an outlook on future scholarly exploration towards efficient and sustainable EBT removal technologies.
Amaku et al. (Sat,) studied this question.