Adsorption of antimony onto iron oxyhydroxides: adsorption behavior and surface structure.

•Antimony adsorption depended on the Sb species, pH, and the type of iron oxides.•Sb(V) adsorption favored at acidic pH, Sb(III) adsorption optimized in wider pH.•Antimony was adsorbed onto the iron oxides by the inner-sphere surface complex.•Bidentate mononuclear (2E) was the dominant form of Sb incorporated into HFO.•XAFS and XPS indicated Sb(III) adsorbed was slowly oxidized to Sb(V).