Effects of electrokinetic treatments on the properties of a salt affected soil

Samudra Jayasekera, John Mewett and Steve Hall

This paper presents experimental results of a study undertaken to investigate the effects of electrokinetic treatments on selected chemical and physical properties of a salt contaminated (saline) soil. The study was conducted as a laboratory scale pilot project using locally available saline soil samples. The soil was subjected to an electric gradient by passing a direct current between inserted electrodes. After certain electrokinetic treatment periods, the properties of the soil were evaluated. The experimental data reveals that electrokinetic techniques could offer a low cost, rapid solution to treat saline soils. The removal efficiency of sodium ions was found to be greater than 90% within a relatively short time period of 14 to 30 days, using low current and voltage systems. After 14 to 30 days, the degree of salinity and sodicity decreased to a very low or negligible level. The unconfined compression strength of the soil increased by between 30% to 100% in 30 days of electrokinetic treatment indicating the improvements in the physical properties, especially in the stress-strain characteristics of the soil. The liquid limit (LL) and plastic limit (PL) increased at the cathode.