Magnetic functionalized Aloe vera-derived activated carbon/ZnO nanocomposite as efficient adsorbents for cephalexin removal from aquatic medium

Since the early 1940s, antibiotics have been extensively used for curative and preventive in humans and animals. Excessive and inappropriate use of antibiotics on the one hand and antibiotics resistance to decomposition, on the other hand, has resulted in their accumulation in the environment, which is a very worrying issue around the world. Therefore, the easy and quick removal of them with high fidelity is a basic need for the health of the global community. The present research was developed to design a new and unique adsorbent based on aloe vera-derived activated carbon (AVAC) for the removal of cephalexin from the aquatic medium. The AVAC as a suitable support was first functionalized with zinc oxide nanoparticles through post-synthesis modification and then magnetized using the in-situ precipitation Fe (II) and Fe (III) ions. The correct synthesis of nanocomposite AVAC/ZnO/Fe₃O₄ was confirmed using analysis of Fourier transforms infrared spectroscopy (FTIR), Vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Brunauer–Emmett–Teller surface area (BET), Field emission scanning electron microscope (FE-SEM). The AVAC/ZnO/Fe₃O₄ nanocomposite was incorporated as an ideal adsorbent for the removal of the antibiotic cephalexin from the aquatic medium. The removal percentage of cephalexin was 96% under the optimum condition (pH = 3, AVAC/ZnO/Fe₃O₄ dosage (1.5 g), reaction time = 60 min, and 5 mg/L of cephalexin). In addition, the system followed the pseudo-second-order (R² = 0.99) and was consistent with the Langmuir isotherm model.