The effect of impregnation ratio and surface modification on the characteristics and performance of activated carbon derived from Ficus carica leaves for Cr(VI) removal

Hexavalent chromium (Cr(VI)) is a water-soluble, highly toxic form of chromium compound that is recognized as a carcinogen and can lead to various health issues. This research investigates the use of activated carbon (AC) derived from Ficus carica leaves for the removal of Cr(VI) from water. The effect of the impregnation ratio on the characterization and performance of activated carbons for removing Cr(VI) was investigated. The physicochemical and textural properties of the produced activated carbons (ACs) were characterized using various analyses, including XRD, SEM, TGA, FTIR, iodine number, and pH of zero charge. It was found that the AC-100 impregnated at a ratio (AC/H₃PO₄) of 100% indicated highly efficient removal of Cr(VI). The prepared ACs have been modified with ethylenediamine (EDA) to enhance their performance. Results show that the adsorption capacity of the modified ACs showed a significant enhancement in comparison to the raw ACs. The maximum adsorption capacities for Cr(VI) removal for the raw AC-100 and its modified form were found to be 155.22 and 203.25 mg/g, respectively, as determined by the Langmuir isotherm. The results of this study confirm that EDA can be used to enhance the effectiveness of activated carbon (AC) derived from Ficus carica leaves in removing Cr(VI) from water.