Activated mangrove biochar for sustainable carbon sequestration

Growing concerns over climate instability have intensified the search for sustainable approaches to mitigate atmospheric CO2 accumulation. This study examines the transformation of mangrove litter (Avicennia marina sp.) into biochar and evaluates how acid activation influences its physicochemical and adsorption characteristics. Biochar was produced through pyrolysis at 400 °C for two hours, followed by treatment with 0.1 M HCl to eliminate mineral residues. Characterization using FTIR, SEM–EDX, and BET analyses revealed that acid activation increased surface area and pore volume while reducing oxygen and metallic impurities. These improvements enhanced microporosity and exposed more active functional groups, leading to greater CO2 adsorption potential. The neutral pH and structural stability of the activated biochar indicate its suitability for application in mangrove sediments, where it may contribute to both carbon stabilization and habitat restoration. Overall, acid-activated mangrove biochar represents a promising material for long-term carbon sequestration and coastal ecosystem resilience.