Physiochemical changes during electrokinetic stabilisation of dredged mud

Electrokinetic stabilisation is a method of improving the geotechnical parameters and behaviour of a soft soil by the application of electric current between electrodes. This improvement is due to the physiochemical changes generated in the soil; however not all the changes are desirable. For instance, the reduction in pH near the anode can increase its corrosion rate. Therefore, it is important to study the physiochemical changes in the soil during electrokinetic stabilisation in order to estimate the behaviour of the soil in response to treatment. This study investigates the suitability of electrokinetic stabilisation for improving the geotechnical parameters and behaviour of dredged mud and demonstrates how the physiochemical nature of the soil changes during the process. For this purpose, two types of electrodes were used to transfer electric current through the soil and the changes in physiochemical nature of the dredged mud were investigated during and after the treatment. This entire process was conducted under closed conditions; that is, no water was allowed to flow through soil during stabilisation. Consequently, the water content of the soil was significantly reduced near the anode and this can be attributed to the changes of pH and physiochemical properties of the soil. It is concluded that this method is very well suited to dewater and consolidate dredged mud slurries.