Immobilization of dopamine on Aspergillus niger microspheres (AM/PDA) and its effect on the U(VI) adsorption capacity in aqueous solutions

In this study, a new surface-modified biobased composite was obtained by modifying the surface of fungal mycelium microspheres (FHMs) with polydopamine (PDA). A. niger mycelium/PDA microspheres (AM/PDA microspheres) were used as a highly efficient adsorbent for the removal of U(VI) ions. This study examined the effects of the initial pH, ionic strength, and electrolyte ions on the U(VI) adsorption capacity of the AM/PDA microspheres. The results confirmed that U(VI) was successfully adsorbed on the AM/PDA microspheres. We compared their adsorption capacity with that of other adsorbents, and the adsorption rate and adsorption capacity of the AM/PDA microspheres were found to be higher than those of the other adsorbents. Equilibrium was achieved after 300 min, and the AM/PDA microspheres had a maximum adsorption capacity of 250.70 mg/g. We aimed not only to investigate the factors that affect the adsorption process but also to provide a new mycelial-based composite adsorbent for U(VI)-contaminated water.