The effect of different types of Permeable Reactive Barrier (PRB) on current density variation of electrokinetic remediation of contaminated soils

The use of an electrokinetic process for remediation of contaminated soil with low permeability has received attention in the last few decades due to the limitations of the typical methods. In this method, by applying an external electric field, pollutants move toward the electrodes with different mechanisms of electroosmosis, electromigration, and electrophoresis. Also, this process can control the direction of movement of pollutants and purify various pollutants. To improve the performance of the electrokinetic process, Permeable Reactive Barriers (PRBs) can be used but it causes changes in the electric current density. In this research, the effect of two types of PRB consisting of zero-valent iron (ZVI) and a mixture of Aluminum and ZVI (AZVI) on electric current density during the electrokinetic remediation of contaminated clay was investigated. The variation of current density was measured daily, and the results show that the experiments with PRB have a smaller than the experiments without PRB, because ZVI has more pore solution and less resistance of particles. ZVI particles have high electrical conductivity and when it is combined with aluminum, the current density decreases with remediation time. Therefore, the suitable selection of PRB due to the effect on the current density and efficiency of the electrokinetic remediation process is very important.

Keywords:

Zero valent iron , electrokinetic , contaminated clay , a combination of iron and aluminum , current density