Abstract
Experiments of sorption of Mn, Co, Ni, Cu and Zn on manganese oxides, hydratedferric oxide, Na-montmorillonite and treated red clay are carried out in connection withthe mechanisms by which transition metals are removed from seawater in marine environments.
The order of sorption affinities of transition metals for Na-montmorillonite, treated redclay and hydrated ferric oxide is Mn<Co<Ni<Zn<Cu, although their distribution coefficientsfor hydrated ferric oxide are about two orders of magnitude larger than those for Na-montmorilloniteand treated red clay. The distribution coefficients of manganese and cobalt formanganese dioxides are much larger than those for hydrated ferric oxide, and the order ofsorption affinities for manganese dioxdes is Ni<Zn<Co<Mn≤Cu.
From the distribution coefficients of transition metals for manganese and iron oxides, andsilicate minerals, it is inferred that manganese oxides play a more important rolethan ironoxides and silicate minerals in removing transition metals from seawater and interstitialwater in deep-sea environments.
