Effects of Electrolytes on the Electrokinetic Properties of Pumice Suspensions

Abstract

Zeta potential values of particles and their sign are very important in many applications. In this study, the zeta potential values of pumice were obtained in the presence of various monovalent (LiCl, NaCl, KCl, NaClO₄, and NaNO₃), divalent (MgCl₂, CaCl₂, SrCl₂, BaCl₂, CuCl₂, MnCl₂, NiCl₂, Na₂CO₃, and Na₂SO₄) and trivalent (AlCl₃ and Na₃PO₄) salts. The zeta potential measurements were performed as a function of pumice concentration, pH, ionic species and electrolyte concentration by electrophoresis technique. The pH profiles of pumice/water systems at different pH values were obtained to determine the stability of suspension pH. The results showed that the zeta potential values of pumice in water did not change significantly with pumice concentration, while they changed mostly with pH. The isoelectric point of pumice was at pH 2.70. It was found that monovalent cations and mono-, di-, and tri-valent anions were indifferent electrolytes for pumice particles, on the other hand, di- and tri-valent cations were potential determining cations for them.

Keywords:

• Electrokinetic properties
• electrolyte solutions
• pumice
• zeta potential

The authors would like to thank to the Management Unit of Scientific Research Projects of Akdeniz University for the support of this work. The authors are grateful to Prof. Dr. Ertuğrul ARPAÇ for his permission to use Zetasizer and FTIR spectrometer instruments.