Biosynthesis of spherical Fe3O4/bacterial cellulose nanocomposites as adsorbents for heavy metal ions

► Spherical Fe3O4/BC nanocomposites were biosynthesized via Gluconacetobacter xylinum fermentation. ► The nanocomposites had high adsorption capacity of heavy metal ions. ► The nanocomposites can be used repeatedly after the elution of heavy metal ions.