SORPTION OF COBALT(II) BY AMORPHOUS FERRIC HYDROXIDE

Sorption of Co(II) ions by amorphous ferric hydroxide was investigated as a function of pH and concentration of Co2+ ions in the supernatant solution. The study was carried out when Co2+ ions were added in the course of formation of the precipitate, and when Co2+ ions were added after the formation of the precipitate. The effect of foreign ions pre sent in solution on the sorption of Co2+ ions was also investigated. I t was found that sorption increases with increasing pH. For each pH so rption isotherm of Co2+ ions by Fe(II) hydroxide fitted the Langmuir e quation. The sorption of Co2+ ions is considered as a counter ion exch ange, the reason of which being a specific adsoption of OH- ions.