Impact of electrokinetic remediation on the environmental health of saline soils.

The Sebkha of Oran, Algeria, spans thousands of hectares and is increasingly affected by the expansion of saline soil, which poses significant risks to humans, plants, and animals. This type of soil is unsuitable for agriculture or construction, making its remediation critical for improving eco-environmental quality. This study investigates the effectiveness of the in situ electrokinetic technique for removing salts from the natural soil of the Sebkha of Oran. Under a constant voltage gradient of 2 V/cm, the removal efficiencies of sodium and calcium after 168 h were 65.77% and 12.67%, respectively. In addition to ion removal, this study examines the broader impact of electrokinetic remediation on soil environmental health by evaluating alterations in key physicochemical parameters, including pH, electrical conductivity, moisture content, and mineral composition. The treatment induced significant physicochemical changes, notably a sharp decrease in pH to 2.2 near the anode and 4.51 near the cathode, indicating strong acidification, while the pH remained neutral in the intermediate zones. Electrical conductivity decreased from 20 dS/m at the anode to 1.28 dS/m at the cathode. Soil moisture content decreased across the profile to 58-86% of its initial level, except at the cathode, where it increased to 118%. XRD analysis revealed the dissolution of gypsum and the formation of new mineral phases. The results clearly demonstrate that electrokinetic remediation effectively reduces salt concentrations in saline soils. However, the novelty of this study lies in revealing that the pronounced acidification near the anode presents potential risks to soil health and long-term environmental stability. Therefore, it is essential to implement remediation strategies that balance effective ion removal with the protection of soil integrity to ensure sustainable land management. Using experimental data, mathematical models were developed to characterize the mobility and diffusion of sodium and calcium ions in the soil, based on their physicochemical properties. These models showed excellent agreement with the observed data, yielding high determination coefficients (R² = 0.993 for sodium and R² = 1.000 for calcium). The models also allowed for accurate estimation of effective diffusion coefficients, which are determined by the physicochemical characteristics of the soil.