Locally accessible <i>Ficus vasta</i> and <i>Ficus sycomorus</i> leaves for adsorption of Cr(VI) from aqueous solution

Hexavalent chromium (Cr(VI) is a toxic and persistent pollutant with serious environmental and health impacts. This study evaluated the biosorption potential of locally available Ficus vasta and Ficus sycomorus leaves for Cr(VI) removal via batch adsorption experiments. Cr(VI) concentrations were quantified using flame atomic absorption spectrophotometry. Under optimal conditions – 60 min contact time, 5 mg L −1 initial concentration, 20 g L −1 adsorbent dose and 180 r min −1 agitation – removal efficiencies reached 88.89% for F. vasta at pH 2 and 91.97% for F. sycomorus at pH 3. SEM revealed irregular, porous surfaces, while Brunauer–Emmett–Teller analysis confirmed type II isotherms and surface areas of 16.485 and 16.743 m 2 g −1 . FTIR identified hydroxyl, carboxyl and carbonyl groups involved in Cr(VI) binding. Adsorption data fit the Langmuir and the Freundlich models, indicating mono-layer coverage with surface heterogeneity. Kinetic analysis aligned with the pseudo-second-order model, suggesting chemisorption. These results highlight Ficus leaves as efficient, low-cost biosorbents for Cr(VI) remediation.