Removal of Methylene Blue and Congo Red Dyes Using Sustainable and Eco‐Friendly Bioadsorbents: A Review

ABSTRACT The continuous increasing discharge of synthetic dyes into aquatic systems seems to be an important environmental and health risk due to their high toxicity and resistance to biodegradation. Among these dyes, methylene blue (MB) and Congo red (CR) are widely used in textile and industrial applications, necessitating sustainable and efficient removal technology. Bioadsorption is considered a low‐cost, renewable, eco‐friendly and effective alternative treatment method. This review critically studies the adsorption efficiency of various bioadsorbents, which is based on the removal of MB and CR dyes, emphasizing key process parameters such as pH, initial dye concentration, temperature and contact time. The comparative analysis communicates that bioadsorbents such as activated and modified biomass pose high removal efficiencies. The review also highlights running trends of bioadsorbent modification, hybrid systems and implementation challenges for industrial applications. By optimizing adsorption conditions and developing or mounting advanced bioadsorbents, bioadsorption can become a sustainable solution for dye‐contaminated wastewater treatment.