Capability of walnut (juglans regia L.) shells as a natural biosorbent of aflatoxin B₁ in a batch experiment model

Abstract

In the present study, the efficacy of low-cost biosorbent obtained from walnut shells for the removal of AFB1 was examined. The characterization of the biosorbent was investigated using SEM, EDS, FTIR, XRD, and pHpzc. Maximum removal (90.5 %) was achieved using 100 mg/mL of biosorbent, pH 7.0 at 45 °C for 45 min with 100 ng/mL of AFB1. The biosorbent’s adsorption capacity was found to be 178.9 mg/g as calculated using the Langmuir isotherm and assumption of monolayer AFB1 adsorption with homogenously dispersed adsorption positions on the biosorbent exterior. The kinetic data indicated the fast AFB1 uptake on biosorbent and followed the pseudo-second-order model. The thermodynamic factors revealed that the adsorption process is viable, spontaneous and endothermic. Furthermore, slight decrease in AFB1 adsorption was observed after repeating the adsorption–desorption process for 5 times. In conclusion, the obtained biosorbent is an economically, eco-friendly and promising material for the removal of AFB1.