Removal of nitrates from spiked clay soils by coupling electrokinetic and permeable reactive barrier technologies

BACKGROUNDThis work aims to describe the removal of a model anion (nitrate) from clay soils using electrokinetically assisted soil flushing coupled with permeable reactive barriers consisting of beds of anion exchange resin and to assess the influence of the electric field on the efficiency of this technology. RESULTSExperiments have been carried out at bench scale with spiked soil using electric fields ranging from 1.0 to 2.0 V cm(-1). Results show that removal of nitrates with this remediation technology is very efficient. About 90% of the nitrates contained in the soil can be removed in less than 1 week of operation with energy consumptions below 75 kWh m(-3). An electric field of 1.2 V cm(-1) was used because no improvements were found operating at higher voltages. CONCLUSIONSThe proposed technology for the removal of nitrates is very effective, making it very promising for the removal of anionic pollutants from soils. The main path of change observed is the direction from anode to cathode. Dispersion in the axial direction is very small. (c) 2014 Society of Chemical Industry