Biosorption of Dye on Biochar from Contaminated Wastewater: Synthesis Property and Mechanism Relationships

Comparative analyses of pure and modified biochars demonstrate that chemical activation, heteroatom doping, metal impregnation, and composite creation significantly improve adsorption capacity, selectivity, and regeneration stability. Kinetic, isotherm, and thermodynamic behaviors are assessed to clarify structure–performance correlations. Critical discussions are presented on key problems associated with experimental inconsistency, regeneration efficiency, and scale-up in realistic wastewater circumstances. The review closes by delineating mechanism-guided design concepts and research goals necessary for the translation of biochar-based adsorption systems into scalable and sustainable industrial wastewater treatment applications.