MAGNETIC-BIOCHAR NANOSORBENT BASED ON OIL PALM EMPTY FRUIT BUNCHES (OPEFB) FOR CHROMIUM (VI) IONS REMOVAL Dwi Catur Cahyaningsih, Dara Chairunnisa, Mutmainna, Shanny Fridarima, Lailatul Ghonimah, Nila Tanyela Berguis*
Universitas Pertamina
Abstract
Magnetic biochar nanosorbent as a bio-adsorbent for remediation of chromium metal waste has been successfully synthesized from biochar composites based on oil palm empty fruit bunches (OPEFB) modified magnetite (\(Fe_3O_4\)).The OPEFB biochar was synthesized using the pyrolysis technique at \(600^\circ C\) with a yield of \(34.8\%\). The \(Fe_3O_4\) nanoparticles on the biochar surface allow the adsorbent to be separated easily and quickly from the solution. The characteristics of the synthesized OPEFB, biochar, \(Fe_3O_4\) and magnetic biochar nanosorbent were analyzed using Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD), also adsorption test using the Freundlich and Langmuir isotherm adsorption models. The IR spectrum of the magnetic-biochar nanosorbent shows the stretching vibration of the O-H bond of the hydroxyl group, the vibration of the C=C strain on the aromatic ring, the C-H bond of the aliphatic group in aromatic substitution and the characteristic peak of Fe-O strain. The XRD diffractogram results show that the resulting magnetic-biochar crystallographic pattern has peaks at \(2\theta\) = \(30.1^\circ\), \(30.5^\circ\), and \(43.1^\circ\) with the designation of fields (220), (311), and (400). The analysis results show that the Freundlich model better at describing the adsorption process of chromium (VI) ions by magnetic-biochar nanosorbent with an \(R^2\) value of 0.7153. The analysis results show that the Freundlich model is better at describing the adsorption process of chromium (VI) ions by magnetic biochar nanosorbent with an \(R^2\) value of 0.7153, compared to the Langmuir model which has an \(R^2\) value of 0.3518.
