Electrochemical desalination of solutions, containing hardness ions

Authors

DOI:

https://doi.org/10.15587/1729-4061.2014.26243

Keywords:

electrodialysis, desalination, anionic membranes, mine water, catholyte, anolyte

Abstract

Processes of the electrochemical desalination of solutions with high content of hardness ions in three-chamber electrolyzer with two anionic membranes MA-41 were studied. On the example of model solutions of magnesium sulfate, it was shown that, in this electrolyzer there is desalination of the solution, placed in the working chamber between the anionic membranes due to diffusion of sulfate anions to the anodic region and hydrolysis of magnesium ions in the working area due to diffusion of hydroxide anions from the cathode chamber to the working.

The peculiarity of the electrolyzer is using anionic membrane from the cathode side. This prevents the migration of cations, including hardness ions, to the cathode region and protects the cathode from the formation of hardness ions hydrolysis products on its surface, especially from deposits on the magnesium hydroxide cathode surface, which significantly increases the electrical resistance of the system. Electrical conductivity in the electrolyzer is maintained by the migration of hydroxide anions, generated at the cathode, from the cathode chamber to the working chamber, thus compensating for the migration of chlorides and sulfates from the working chamber to the anode region. It was shown that hydroxide anions virtually do not pass to the anode chamber since they are bound in the working chamber during the hydrolysis of magnesium ions, and with the presence of hydrocarbons during their conversion into carbonates. This promotes the mitigation of the solution in the working chamber and its purification from chlorides and sulfates. In the anode chamber during the separation of oxygen and protons on the anode there is the formation of sulfuric acid. Chlorine after oxidation at the anode is separated from the acidic medium in the form of gas and is absorbed by an alkali solution with the formation of sodium hypochlorite.

Similar processes are implemented during mine water desalination in this electrolyzer when adding magnesite to the working chamber near mine water. 

Author Biography

Ірина Миколаївна Макаренко, National Technical University of Ukraine “KPI” Peremogy av. 37, Kyiv, Ukraine, 03056

PhD, Senior Research Fellow

Department of Ecology and Plant Polymers Technology

References

  1. Honcharuk, V. V., Chebotarova, R. D., Bagryi, V. A., Bashtan, S. Y., Remez, S. V. (2005). Softening water electrolyzer with ceramic membrane. Chemistry and technology of water, 27 (5), 460–470.
  2. Xu, F., Innocent, C., Pourcelly, G. (2005). Electrodialysis with ion exchange membranes in organic media. Separation and Purification Technology, 43 (1), 17–24. doi:10.1016/j.seppur.2004.09.009
  3. Duganova, R. Y., Shushkevich, E. O., Barieva, E. R. (2003). Studing of the dynamics of the process water softener unit ECHO. Proceedings of the universities. Energy problems, 1–2, 128–135.
  4. Wiśniewski, J., Różańska, A. (2007). Donnan dialysis for hardness removal from water before electrodialytic desalination. Desalination, 212 (1-3), 251–260. doi:10.1016/j.desal.2006.11.008
  5. Pisarska, B., Dilevski, R. (2005). Analysis of the conditions for obtaining H2SO4 and NaOH solutions of sodium sulphate by electrodialysis. Journal of Applied Chemistry, 78 (8), 33–38.
  6. Shabliy, T. O., Ivanuk, V. V., Gomelia, M. D. (2011). Electrodialysis sodium chloride to produce hydrochloric acid and alkali. Journal of NTUU "KPI". Chemical engineering, ecology and resource, 1 (11), 67–71.
  7. Goltvianitska, O. V., Shabliy, T. O., Gomelia, M. D., Stavska, S. S. (2012). Removal and separation of chlorides and sulfates in ion-exchange water desalination. Eastern-European Journal of Enterprise Technologies, 1/6 (55), 40–44.
  8. Ayala-Bribiesca, E., Pourcelly, G., Bazinet, L. (2007). Nature identification and morphology characterization of anion-exchange membrane fouling during conventional electrodialysis. Journal of Colloid and Interface Science, 308 (1), 182–190. doi:10.1016/j.jcis.2006.11.012
  9. Chkhenadze, N. V., Kurtshalia, T. S. (2004). By definition, the permissible value of calcium hardness in electrodialysis mineralized water with simultaneous concentration. GEN: Georg. Eng. News, 4, 118–122.
  10. Kucheryk, G. V., Omelchuk, Y. A., Gomelia, M. D. (2011). Electrochemical chloride extraction of natural water and alkali regeneration solutions. Collected Works of Sevastopol National University of Nuclear Energy and Industry, 2 (38), 189–196.
  11. Shabliy, T. O., Gomelia, M. D., Panov, E. M. (2010). The electrochemical recycling of waste solutions generated during regeneration of cation. Ecology and industry, 2, 33–38.
  12. Shabliy, T. O. Design of the new reagents and technologies for prevention of aquatic contamination by industrial drain waste. Environmental Safety, 39.

Published

2014-08-08

How to Cite

Макаренко, І. М. (2014). Electrochemical desalination of solutions, containing hardness ions. Eastern-European Journal of Enterprise Technologies, 4(6(70), 48–53. https://doi.org/10.15587/1729-4061.2014.26243

Issue

Section

Technology organic and inorganic substances