Electroremediation of sodium bentonite contaminated with phenanthrene and its modeling with a Nernst-Planck equation

abstractin this study, the removal of pahs from a clay-based soil, using electrokinetic remediation, was explored. the experiments used phenanthrene-spiked bentonite as a simplified model representative of a vertisol soil polluted by hydrocarbons. experiments were performed using a 1-d cell where 80 cm3 of phenanthrene-spiked bentonite was subjected to electrokinetic remediation using a constant current density. the results obtained from these experiments were compared with those predicted by a mathematical model based on a nernst-plank equation for the description of electromigration, electroosmosis and diffusion. although significant electro-osmotic flow was observed, comparison between the experimental and predicted results indicated that the removal of phenanthrene was experimentally faster than predicted by the model. the greatest differences were found in the soil regions closer to the anode. to account for this behavior a first-order reaction in the aqueous phase in the regions closer to the anode was postulated and introduced into the model as the observed sink for phenanthrene. under these conditions, much better agreement was observed between the experimental and model results. graphical abstract open image in new window