Synthesis and Characterization of Fe_xO_y/Activated Biochar Composite from Patchouli Biomass as Potential Adsorbent for Polluted Water Remediation

Biochar is a porous material which can be produced by biomass waste pyrolysis and modified using metal oxide to improve its adsorption performance. Activated biochar (AB) was synthesized from patchouli biomass waste to study the effect of calcination tempera-ture on its potency as a drug pollutant adsorbent. Research processes included the bio-mass pyrolysis with CoCl₂ activator, AB impregnation with FeCl₃, FeCl₃/AB calcination at various temperatures, product characterizations (X-ray diffraction, FTIR spectrometry), and paracetamol adsorption test at various concentrations. The paracetamol concentra-tions were analyzed using UV–Vis spectrophotometry. The adsorption data was treated using Langmuir, Freundlich, and Dubinin–Radushkevich (DR) models. The diffracto-grams indicated the α-Fe₂O₃, γ-Fe₂O₃, FeFe₂O₄, and carbon turbostratic structures. The Fe_xO_y crystallinity increased by increasing temperature. The FTIR spectra significantly indicated the functional group changing at 600 °C. In the adsorption test, the Fe_xO_y/AB-800 compo-site gave the highest adsorption capacity of 53.087 mg/g (Langmuir) with a correlation co-efficient of 0.964 (very high correlation), and the physical adsorption mechanism based on adsorption energy of 530.330 J/mol (DR) and 1/n value of 0.62 (Freundlich) provided the favorable adsorption based on both the RL of 0.457 (Langmuir) and the n constant of 1.579 (Freundlich). Thus, the Fe_xO_y/AB-800 composite has potential as an adsorbent of organic pollutants such as paracetamol.