X‐Ray Absorption Fine Structure Spectroscopy Study of Arsenate Adsorption on Schwertmannite

We studied arsenate adsorption on schwertmannite by means of XAFS. Our results show that arsenate is bound to one or two iron octahedra and individual iron octahedra in schwertmannite become more regular after the adsorption. At the same time there is an increase of disorder in polymeric chains of iron octahedra. This suggests that the release of local strain is related to the overall stability of arsenate‐adsorbed schwertmannite.