Speciation of cobalt, zinc and mercury in marine environment

Abstract

Speciation of cobalt, zinc and mercury has been investigated using solid and liquid ion exchangers. Batch equilibration method and column chromatography have been used to speciate the metal ions. Cobalt species is found to be present mainly as a monopositive ion with an appreciable concentration of cobalt

sulphate complexes. The uptake from anion exchanger is found to be less. In case of zinc, the metal ion is found to exist partly in the cationic, anionic and hydrolysed forms which exist in labile equilibrium. Mercury has been found to exist mainly as anionic chloro complexes alongwith hydrolysed or organically bound complexes. In all the cases, there is a good agreement with the data obtained using simulated and actual sea water, indicating that the general speciation of the metal ion is governed by the anions like chloride, sulphate and carbonate/hydroxide present in sea water.