The impact of electrokinetic treatment on a loamy-sand soil properties

Over the years, electrokinetic treatment has been successfully applied in the remediation of inorganic and organic contaminants. In this technology, an electric field is utilised to promote the movement of contaminants towards the electrode chambers. However, other native compounds that are present in the soil can also be mobilised. Although this effect can have a great influence on soil properties, there has only been limited research evaluating the soil functionality after electrokinetic treatment.In this work, we carried out the electrokinetic treatment of soil spiked with diesel fuel (20,000 ppm). The use of citric acid as a processing fluid was evaluated for enhancement of the electro-osmotic flow. In addition, biostimulation was also tested to facilitate the biodegradation. The efficiency of the treatment at two voltages (1 V cm−1 and 2 V cm−1) was determined based on diesel fuel removal and the impact of the technology on physico-chemical and biological parameters. More powerful electric fields generated the best pollutant removal; however, the soil properties were drastically changed. It is suggested that after electrokinetic treatment, some amendments should be performed to return the soil to its initial condition.

► We remove 20,000 ppm diesel-fuel from soil by using electrokinetic treatment (15 d).
► We studied the impact of the technology on physical-chemical soil parameters.
► We studied the impact of the technology on biological soil parameters.
► We found that the presence of citric acid in the soil increased microbial activity.