Electrokinetic Desalination of Compound Building Materials by Applying Electric Field

Abstract

Damaging of building materials is directly connected to the salt crystallization. The present research is based on removal of NaCl from compound building materials, where a direct current (DC) electric field was applied to the mortar plus bricks system. The main objective of this work is to investigate the electrokinetic desalination methodology that can provide sufficient removal of salts. pH neutralization in the surrounding of mortar plus bricks system is crucial to obtain sufficient desalination. For this purpose, the electrodes across the brick were inserted in kaolin clay mixed with buffer agents to suppress the pH changes. Most of the experiments were performed with kaolin clay and sponge. The concentration of chloride ions and sodium ions in all the segments and clay poultice was measured using argentometric titration method and flame photometer, whereas the pH variations in the entire system was measured by using pH indicator papers. The electrokinetic desalination was found to be an efficient method as 86 % removal of chloride and 80 % removal of sodium was achieved.