Highly-efficient adsorptive removal of tetracycline using magnetic sugarcane bagasse biochar modified by lanthanum

As one of the agricultural wastes, sugarcane bagasse was easily pyrolyzed under low temperature to obtain bagasse biochar. Lanthanum-modified Fe3O4 particles were immobilized on the bagasse biochar to prepare La-modified magnetic biochar. The magnetic biochar was characterized by scanning electron microscope and X-ray photoelectron spectroscopy. It was found that the sizes of these biochar flakes were predominantly within 50 µm. At the same time, La species and magnetic particles are well combined with the biochar substrate. The magnetic biochar with a presumed molar ratio of La/Fe3O4 at 1:100 demonstrated a higher adsorption capability, which was enhanced by 69.8% compared to the raw bagasse biochar. The experimental points were quite close to curves simulated by both Langmuir and Freundlich isotherm models. From Langmuir model, the R2 values were 0.984, 0.980 and 0.983 at 288, 298 and 308 K, respectively. The maximum adsorption capacity (qmax) for tetracycline reached 122.5 mg/g at 298 K and qmax increased with a rise in the reaction temperature, indicating the adsorption process was endothermic. © 2019 Technoscience Publications. All rights reserved.