Cadmium biosorption potential and kinetic behavior of endophytic Fusarium verticillioides and its green synthesized silver nanoparticles (GSNPs)

Silver nanoparticles (GSNPs) were synthesized from extracellular metabolites of endophytic isolates of Fusarium verticillioides (KT587649) to evaluate their efficiency as new biosorbent agents for the exclusion of cadmium Cd (II) from aquatic systems. The GSNPs were characterized through X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results show that the most efficient Cd (II) removal rate by both biosorbents was at pH 7.0. The optimal contact times were 30 and 40 min by F. verticillioides and GSNPs, respectively. Langmuir adsorption isotherms revealed that the highest calculated adsorption capacities of F. verticillioides and GSNPs for Cd (II) were 185±0.25 mg/g and 176±0.18 mg/g, respectively. The harmonized adsorption isotherms (between the Freundlich isotherm and Langmuir models) indicated a high correlation coefficient (r2 > 0.97). The kinetics of the biosorption process fitted well with the pseudo-second-order kinetic model. This study has thus confirmed the biosorbent capacity of F. verticillioides and its GSNPs for the exclusion of Cd (II) from any contaminated aquatic system and shows it is an eco-friendly method with great feasibility and potential to convey economic and other benefits in wastewater treatment technologies