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

In this paper, spherical Fe3O4/bacterial cellulose (BC) nanocomposites as adsorbents for heavy metal ions were biosynthesized from Gluconacetobacter xylinum by agitation fermentation. A pH controlling embedding method as a new approach was applied to biosynthesize spherical Fe3O4/BC nanocomposites. Scanning electron microscopy (SEM) images indicated that the Fe3O4 nanoparticles were enwrapped homogeneously in the spherical BC. The spherical Fe3O4/BC nanocomposites with 33 wt% ferrous loading had 41 emu/g of the saturated magnetization (σs) and 27 Oe of the related coercivity. The adsorption and elution capacities of the spheres for Pb2+, Mn2+, and Cr3+ were evaluated. The results indicated that the spherical Fe3O4/BC nanocomposites had high adsorption capacities and were recyclable after the elution of heavy metal ions. Compared with conventional preparation procedure for cellulose spheres, spherical Fe3O4/BC nanocomposites can be readily prepared without sophisticated steps and have high adsorption and elution capacities.