Electrodialysis for desalination of brackish groundwater in coastal areas of Korea

Abstract

Electrodialysis (ED) with ion-exchange membranes was applied for desalination of salted groundwaters from three places in coastal areas in Korea. The ED system produced high quality of permeate. However, substantial resistance built-up was identified in one particular groundwater sample. Possible causes of the fouling were sought for better understanding of brackish water desalination. Several model samples with different ion composition, that is, Na₂SO₄, MgSO₄, CaSO₄ at the same conductivity condition, that is, 1,200 μs/cm were tested to understand effects of monovalent and divalent ions on water quality and increases in resistance of the ED system. In addition, organic matter concentrations were compared in the sampled groundwaters. The ED performance of the three model solutions showed similar tendency in operation time and current curve and did not explain the discrepancy of ED performance of the groundwater. Dissolved organic carbon concentration results implied that organic matter in the groundwater played an important role in ED operation.

Keywords:

• Electrodialysis
• Groundwater
• Brackish water
• Ion removal
• Desalination

Acknowledgment

This study was supported by Konkuk University in 2011.

Notes

Presented at The Fifth Desalination Workshop (IDW 2012), 28–31 October, 2012, Jeju, Korea