In this project, we modified the biochar adsorbent using iron oxide nanoparticles coated with humic acid to remove methylene blue, a cationic dye. The prepared adsorbent was characterized using various analytical techniques, including Fourier-transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller surface area measurement (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA). The magnetic properties were determined using a vibrating sample magnetometer (VSM). Surface adsorption experiments were conducted to investigate the factors influencing the surface adsorption of methylene blue by the prepared biochar adsorbent in aqueous environments. Various parameters such as solution pH, contact time, adsorbent dosage, and initial dye concentration, were examined. The results of surface adsorption analysis at different concentration revealed that the adsorption behavior on the adsorbent could be accurately described by the Langmuir isotherm and the elovich kinetic equation. The isotherm parameters for surface adsorption were also determined.
