Author: A.Iryani, R. Rahayu , L.J. Kusumawardani, L. Efiyanti, Y. Syahputri, F. Nuraeni, D. Kartina, D.M. Salam, A.N. Laksmita, C.R. Kholibrina, Aswandi, and Yuniawati

DOI: http://doi.org/10.31788/RJC.2026.1919513

This study was conducted to synthesize and characterize activated carbon from corn stalk and husk waste usinganacid activator. The synthesis was carried out through carbonization at 400 °C for 3 hours, followed by activationusing HCl with five variations of activated carbon weight combinations: BJ100, KJ100, BJ30KJ70, BJ70KJ30, andBJ50KJ50. Characterization was performed using FTIR and SEM-EDS. The results of the FTIR spectra revealeddifferences in functional groups between the various combinations, which identified the diversity of chemical composition on the activated carbon surface. Morphological analysis using SEM revealed that each combinationhadsuccessfully formed pores, albeit with varying numbers and sizes. Optimization tests were conducted by comparingthe reduction of iron (Fe) level under varying pH conditions, concentrations, and contact times. The concentrationof 10 mg/L is the optimum concentration to reduce the Fe metal concentration. The optimum pH is at pH3 for BJ100 and BJ30KJ70, and at pH 4 for KJ100. The ideal contact duration for activated carbon to adsorb Fe is 30 minutes. BJ100 and KJ100 followed the Freundlich model, while the activated carbon combination BJ30KJ70 has a maximal adsorption capacity of 0.5996 mg/g and adhered to the Langmuir model. These results demonstrate that activatedcarbon derived from corn stalks and corn husks can effectively reduce the concentration of Fe metal.

Keywords: Carbonization, Freundlich, HCl, Langmuir, Reduction