Highly efficient adsorptive removal of the carcinogen aflatoxin B1 using the parasitic plant Cuscuta corymbosa Ruiz & Pavon

Abstract

The ever-growing consumption of herbs around the globe has motivated the researchers to acquire practical knowledge about other potential applications in human and animal health. In this research, an unmodified adsorbent prepared from the holoparasitic herb C. corymbosa was utilized for the removal of the carcinogen aflatoxin B1 (AFB1) from aqueous solutions. The adsorbent was characterized by Fourier transform near-infrared/mid-infrared spectrophotometry (FT-NIR/MIR), environmental scanning electron microscopy (ESEM), energy-dispersive X-ray fluorescence spectroscopy (EDX), X-ray diffraction (XRD), and point of zero charge (pHpzc). Adsorption experiments were carried out in batch systems, and the experimental data was used for isothermal (Langmuir and Freundlich) and kinetic (linear and non-linear forms of the pseudo-first and pseudo-second order) models. In general, the unmodified adsorbent removed AFB1 independent of the solution pH, showing a theoretical adsorption capacity of 555.76 mg AFB1/g at 303 K, significantly higher than that reported for other plant-based adsorbents and comparable with the efficiency of various inorganic adsorbents. Non-electrostatic attractions such as hydrogen bonding and dispersion forces along with complexation mechanisms were the primary interactions responsible for the adsorption of the pollutant. Our results clearly show that C. corymbosa could be a promising material for practical adsorption applications in the drinking water industry.