Enhanced Adsorption Efficiency through Biochar Modification: A Comprehensive Review

Abstract

This comprehensive review focuses on modified biochar and its applications as highly efficient adsorbent for the removal of contaminants from aqueous solutions. Biochar possesses favorable properties like numerous functional groups, large surface area, and charged surfaces, making it an appealing and environmentally friendly sorbent. However, designing biochar for precise pollutant removal necessitates evaluating variables like pyrolysis temperature, nature of biomass, biochar dosage, solution pH, composition, residence time, and physicochemical characteristics. Addressing these factors can amplify the adsorbent capacity of biochar. Various mechanisms, including pore filling, electron donor–acceptor (EDA) interactions, precipitation, electrostatic interactions, hydrophobic attractions, and ion exchange, contribute to pollutants’ adsorption. The current modification methods are often expensive and may lead to secondary pollution. Hence, the present review emphasizes methods of preparing environmentally friendly and financially affordable modified biochars for industrial and practical applications while minimizing adverse effects and maximizing positive outcomes for a sustainable future.