Treatment of air pollution control residues with iron rich waste sulfuric acid: Does it work for antimony (Sb)?

► Fe-rich, sulfuric acid waste was efficient to immobilize Sb in APC residues. ► Sb was strongly sorbed to green rust formed in the stabilization process. ► Sb in porewater of stabilized APC residues occurred mainly as Sb(V). ► Leaching of Sb from untreated APC residues was strongly pH dependent. ► Antimony in water extracts of APC residues occurred exclusively as Sb(V).