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

•Adsorbent AM/PDA microspheres for U(VI) adsorption.•PDA immobilization on A. niger mycelium as a biomaterial is a new strategy.•The U(VI) adsorption process was rapid, and equilibrium was established within 300 min.•PDA was used to enhance the surface activity of the AM microspheres.•The U(VI) removal efficiency of the AM/PDA microspheres from simulated real wastewater was evaluated.