Analysis of mobilization of inorganic ions in soil by electrokinetic remediation

Abstract

Saline soil has imposed a serious threat on many expressway engineering and agricultural areas. This paper describes the performance of saline soil treatment using electrokinetic remediation technology. Comparison study involving sample soil and in situ soil is carried out. Two different electric fields, i.e., uniform and non-uniform are utilized to promote the migration of inorganic ions contained in the soil toward the electrode area. The effects of different electric field types and potential gradient ion migration rate in soil are investigated. The test result reveals that a uniform electric field of a constant potential gradient of 1 V/cm drives the Cl− through the sample soil at a rate of 1.36 cm/h. Moreover, larger potential gradients could make ions migrate faster, but more electrical energy is consumed in such a way. Compared with uniform electric field, the non-uniform process maintains the soil pH values more effectively and consumes less electrical energy. A desirable result of removing Na+ in soil is expected using electrokinetic remediation technology under four-times scaling up of soil volume.