Synthesis of iron oxide nanoparticles embedded biochar adsorbent for wastewater dye removal

Abstract

This study presents the synthesis of a novel magnetic biochar composite (MBC) for efficient removal of dye from aqueous solutions. Vegetable peels were washed several times using a distilled water to remove dirt and impurities which is present in the peels. Then the washed peels are dried in an open-air surface for about 1 week. The peels, after drying, were ground into a fine powder using a pulverizer and then sieved to obtain a uniform particles size. Once sieved the biomass was prepared then it undergoes pyrolysis at 550 °C for 20 minutes using a muffle furnace. Subsequently,9.5 grams of ferrous sulphate and 10.5 grams of ferric chloride is mixed with 200 mL of distilled water and stirred at 450 RPM for 1 hour. To facilitate the deposition of iron oxide nanoparticles a freshly prepared NaOH solution was added dropwise to achieve a pH 11. The resulting mixture was stirred for an additional hour, allowed to stand at room temperature for 30 minutes, filtered, washed with distilled water and then dried at 100 °C. Then the prepared biochar adsorbent and iron oxide nanoparticles are mix together for 1 hour for embedding them. Characterization was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) and Ultra violet visible spectroscopy (UV-Vis) confirming the successful incorporation of iron nanoparticles onto the biochar surface. Adsorption studies revealed that product effectively removed over 78% of dyes from aqueous solutions. The composite exhibited superparamagnetic properties, enabling easy separation from the solution using a small bar magnet. These results indicate that the adsorbent embedded nanoparticles is a promising, sustainable adsorbent for wastewater treatment applications.