A comprehensive review of the adsorption of Eriochrome Black T (EBT) from aqueous solutions

This study presents a comprehensive review of adsorption-based techniques for the removal of Eriochrome Black T (EBT) dye from aqueous solutions. The objective was to consolidate recent findings on adsorption isotherms, kinetics, mechanisms, thermodynamics, and regeneration, to evaluate the efficiency and sustainability of various adsorbents. The review was motivated by the persistence and toxicity of EBT, which threaten aquatic ecosystems and human health, thereby making its removal essential for environmental protection. A systematic analysis of over 50 studies revealed that EBT uptake is predominantly described by the Langmuir isotherm and pseudo-second-order kinetics, with mechanisms involving electrostatic attraction, hydrogen bonding, and π–π interactions. Thermodynamic data generally indicate spontaneous and exothermic adsorption, while several adsorbents maintain over 80 % capacity after five regeneration cycles. However, challenges remain, including high production costs of advanced adsorbents, reduced efficiency after repeated regeneration, and limited validation under real wastewater conditions. These findings demonstrate adsorption as a cost-effective and scalable method for EBT removal. Future research should focus on the development of low-cost sustainable materials, improving regeneration efficiency, pilot- and industrial-scale applications, comprehensive life cycle and techno-economic analyses, treatment of real wastewater beyond laboratory-prepared solutions, and the integration of regulatory and policy frameworks to enable practical and sustainable implementation. • The adsorption of EBT from aqueous solutions was comprehensively reviewed. • EBT adsorptive uptake follows the Langmuir isotherm and pseudo-second-order kinetics. • The mechanisms involve electrostatic attraction, hydrogen bonding, and π–π interactions. • The thermodynamics of EBT uptake is predominantly spontaneous and exothermic. • Most adsorbents retain over 80 % capacity after five regeneration cycles.