Mitigation of Salinity Hazard from Low Permeable Soil by Electrochemical Treatment: A Laboratory Based Investigation

Abstract

Soil salinization has become a serious problem and an environmental issue of worldwide significance, affecting the ecosystem biodiversity, human health and civil engineering infrastructures. This research investigated the efficiency of the electrochemical treatment (ECT) for remediation and mitigation of salinity hazard. The salinity of soil samples, including magnesium (Mg²⁺), sulfate ($\text{SO}_{4}^{2\text{-}}$) and chloride (Cl⁻) contents, was investigated using different duration time of 72 and 120 h. The originality of this research is to investigate the effect of the processing time on the migration and removal of harmful salt ions. During the treatment time, Mg²⁺ ions were transferred toward the cathode, whereas $\text{SO}_{4}^{2\text{-}}$ and Cl⁻ ions were transported toward the anode by electro-migration. The optimal removal efficiency for Mg²⁺ was 90 and 93% after 72 and 120 h respectively, while the extraction rate of $\text{SO}_{4}^{2\text{-}}$ ions was 5 and 15%. The removal of magnesium was substantially higher than that of sulfate and chloride ions, owing to the combined action of electro-osmosis and electro-migration mechanisms. On the other hand, increasing in the processing time allowed better transfer of ions species, enhancing thereby salts extraction. This study demonstrated that the harmful effect of salinity can be readily mitigated by ECT treatment. Therefore, ECT treatment could be successfully used for mitigation of salinity hazard and restoration of salt affected soils for environment protection and civil engineering constructions management.