For CN/Cu = 3 (Fig. 11), it can be seen that the adsorption density
increased with the increase in the ionic strength.When the “spectator”
cation was Ca2+ ions, added as CaCl2, the adsorption density was relatively
higher than in the presence of Na+ and K+ ions, added as NaCl
and KCl, respectively. At similar experimental conditions (pH 10.5 and
CN/Cu = 3), Raman findings demonstrated that increases in the ionic
strength from 0 to about 4 mol•kg−1 (addition of Na+ ions) have no