Mercury(II) Adsorption on the Maikop Series Rocks and Mud Volcano Clays

The acid–base properties of the surface of Maikop series clays and mud volcano clays, as well as their adsorption properties with respect to mercury(II) ions, were studied. It is shown that pH_PZC for the former is 7.1 on average; for the latter, 9.0. The pH_PZC value for mud volcano clays is consistent with the pH values in the waters of mud volcanoes of the Kerch–Taman region. When the mass ratio of the sorbent and solution is 1 : 900, adsorption equilibrium occurs after 4 days with active stirring. Experimental data on mercury adsorption from NaCl–NaHCO₃ solution on natural sorbents are best described by the Redlich–Peterson and Toth equations. The process of mercury adsorption on clays of the Maikop series is more intense than that on mud volcano clays.