Magnetic rice husk-based biochar for removal of aflatoxin B1 from peanut oil

Aflatoxin B1 (AFB1) contamination in peanut oil can lead to serious food safety problems. Thus, the development of AFB1 decontamination technology is an urgent and necessary matter. Herein, a renewable and effective biomass-derived adsorbent, namely magnetic rice husk-based biochar (MRHB), was prepared and successfully used for the removal of AFB1 from peanut oil. The adsorption conditions, adsorption mechanism, reusability and cytotoxicity of MRHB were systematically studied. The results revealed that the adsorption characteristic of MRHB followed the pseudo-second-order kinetic and the Langmuir isotherm models, and was a spontaneous and endothermic process. Due to the synergism of carbon and silica active sites, the maximum adsorption capacity of MRHB was as high as 951.1 μg/g, and over 95% of AFB1 could be removed from peanut oil. Additionally, MRHB showed negligible cytotoxicity and negative effects on the nutritional quality of the oil. Thus, this low cost, high-efficiency, and high-safety MRHB with magnetic separation capacity is a promising adsorbent that can be used for the removal of AFB1 from oils.