Influence of inherent iron and oxygen concentrations on selenite sorption process using bentonite

Materials interacting with inorganic selenium from the perspective of electrochemical sensing

“…For natural clays, it was suggested that Fe, which is often a component of clays, is the main oxyanion-binding moiety and its redox state is strongly dependent on pH and oxygen content. Anoxic conditions have been found slightly more sufficient for selenium sorption on bentonite 200 . Another way to enhance binding of selenite on natural clays is to use high pH solution (above pH of 8) and the addition of Ca 2+ ions which co-precipitated with SeO3 .…”