Influence of anolyte and catholyte composition on TPHs removal from low permeability soil by electrokinetic reclamation

Removal of TPHs from polluted soil by electrokientic reclamation was done by using different electrolytes (anolyte and catholyte). The initial concentration of TPHs in soil was 23,000 ppm and removal efficiencies reached almost 90% for a combination of 0.04 M NaOH and 0.1 M Na2SO4 in the anode and cathode chambers, respectively. Electroosmotic flow and TPHs desorption were measured under galvanostatic conditions (1.95 mA cm−2 and electric field <10 V cm−1). The study is supported on the electrokinetic transport model for low permeability soils. Electrolytes (anolyte and catholyte) were maintained at constant ionic composition to keep constant boundary conditions, thus launch a pseudostationary state for fluid and charge transport throughout the soil. It was also observed that electrolyte concentration favored TPHs desorption as well as their transport throughout the soil by electroosmotic flow from anode to cathode. Both, electrolytes concentration and wetting solution helped to maintain a constant pH profile during electroreclamation, thus a sustained fluid flow from anode to cathode.