Adsorption of heavy metal cations on hydrated oxides and oxides of iron and aluminum with different crystallinities

Abstract

The adsorption of Cu2+, Zn2+, and Mg2+on the hydrated oxides and oxides of iron and aluminum with different crystallinities was investigated. The effects of pH, ionic strength of the bulk solution, competing metal cations, metal cation concentration on the adsorption were evaluated. The adsorption of Cu2+, Zn2+, and Mg2+on the hydrated oxides and oxides of iron and aluminum increased with increasing pH of the bulk solution, and the adsorption sequence was in the order Cu2+>Zn2+>Mg2+. The ionic strength of the bulk solution did not affect the adsorption of Cu2+and Zn2+. Competitive adsorption of Zn2+and Mg2+was observed in the presence of Cu2+. The X-ray amorphous hydrated oxides and oxides of iron and aluminum with a low crystallinity showed a larger adsorption capability for heavy metal cations than those with a high crystallinity. © Taylor & Francis Group, LLC.