Abstract
The adsorption ofCoof trace concentration in sea water on the hydroxides ofFe, Al, Mn, Si, and marine sediments and ion-exchange resins was studied. The degree of adsorption on the hydroxides increased as the pH value of sea water was raised from 6 to 9, and the adsorption on aluminium hydroxide was most remarkable. The adsorption ofCoon the hydroxides ofAl, at pH value 9, was higher in the artificial sea water than in the natural sea water.
The minimum distribution coefficient of Co was obtained at pH value 7 with both marine sediments assayed in this work, although the cation exchanger showed a slight decrease of adsorption accompanied with the increase of pH value of sea water from 5 to 9. From the values of distribution coefficients ofCoon the sediments and ion exchanger of the varied concentrations in sea water, it was presumed that one of the sediments functioned as a single sort of adsorbent similar to the cation exchanger, but in the case of another sediment, there accompanied some other kind of adsorption in addition to cation exchange. The adsorption ofCoto the sediments and cation exchanger was reduced as the concentration of glycine and glycollic acid in sea water was increased. As to the other kind of amino acids, aspartic acid showed the distinguished effect of hindrance to the adsorption in comparison with alanine, leucine and glutamic acid, which showed the adsorption of the similar degree to glycine.
On the other hand, lysine showed the promotive effect on the adsorption unlike the other amino acids assayed in this work. It was observed that interfering effect of amino acids on the adsorption ofCowas dominated by the chelate formation constant of amino acids withCo2+.
