Adsorption characteristics of magnetic nanoparticles coated mixed fungal biomass for toxic Cr(VI) ions in aquatic environment

In this research, the adsorptive removal of Cr(VI) ions from the aquatic environment have been studied using newly synthesized magnetic nanoparticles coated mixed fungal biomass (MNP-FB). Two fungal biomass such as Aspergillus fumigatus and Aspergillus niger were isolated, screened, and utilized as a precursor for making an adsorbent. Molecular characterization of isolated fungal species was recognized using 18S rRNA sequencing. The characterization studies of the MNP-FB were evaluated using Fourier Transform Infrared Spectrophotometer (FTIR) and Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses. Optimization studies were studied to check the effect of different operating variables such as pH (2.0-9.0), equilibrium time (10-90 min), MNP-FB dosage (0.1-1.0 g/L), temperature (30-60 °C) and concentration of Cr(VI) ions (50-500 mg/L). Additionally, Freundlich isotherm model fits well for the adsorption of Cr(VI) ion using MNP-FB. The adsorption kinetics was interpreted well by Pseudo-first order model. The thermodynamic study concluded that Cr(VI) ions removal by MNP-FB was exothermic and appreciative at low temperatures. The monolayer adsorption efficiency of MNP-FB for Cr(VI) ions was measured as 249.9 mg/g. The current results reveal that MNP-FB has considered being a proficient and economically suitable material for the Cr(VI) ions removal from the water environment.