Aflatoxin B1 detoxification by magnetic carbon nanostructures prepared from maize straw

Abstract

Magnetic carbon nanocomposites were prepared from maize wastes and were characterized by surface area analyzer, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric/differential thermal analysis (TG/DTA), and electron dispersive X-ray (EDX). The presence of iron oxide on the adsorbent surface was confirmed from SEM, XRD, and FT-IR analysis. Freundlich and Langmuir isotherms were used for the determination of adsorption parameters. The effect of pH on adsorption process was evaluated, and a decline in percent adsorption was noted at high pH. The equilibrium time at pH 7 and 3 was 96 and 180 min, respectively, and nearly 90% removal of aflatoxin B1 was achieved for both adsorbent. Pseudo-first-order and pseudo-second-order kinetic equations were used to analyze the kinetic data. Best fit was obtained with pseudo-first-order kinetics equation. The thermodynamics parameters were also determined, ΔS° was positive (64.438 kJ mol⁻¹ deg⁻¹) while ΔH° (−16.24 kJ mol⁻¹) and ΔG° were negative (−1.949, −2.593, −3.238, and –3.882 kJ mol⁻¹ corresponding to 30, 40, 50, and 60°C, respectively).

Keywords:

• Aflatoxins
• Adsorption
• Equilibrium time
• Maize straw