Treatment of artificial and real co-contaminated soil by an enhanced electrokinetic-Fenton process with a soil flushing method

Abstract

The electrokinetic process with Fenton oxidation is a useful method to remediate soils co-contaminated with hydrophobic organics and heavy metals. In this study, an enhanced electrokinetic-Fenton process with a soil flushing method was investigated for the homogeneous and simultaneous removal of total petroleum hydrocarbons (TPHs) and zinc from contaminated soil. In addition, we investigated the removal mechanisms of different types of organic contaminants in real co-contaminated soil with TPHs, polycyclic aromatic hydrocarbons (PAHs), and zinc. In the artificially spiked soil, TPHs were homogeneously treated, and the removal of TPHs and zinc significantly improved using 10 % hydrogen peroxide (H2O2) with 20 mM sodium dodecyl sulfate (SDS) in the anode and 20 mM SDS and 20 mM NaOH in the cathode. In the real co-contaminated soil, the remediation efficiencies of TPHs and zinc decreased because of the natural soil properties. However, we found satisfactory simultaneous treatability of TPHs and PAHs using 20 % H2O2 with 20 mM SDS in the anode and 20 mM SDS and 20 mM NaOH in the cathode. Furthermore, the removal of individual PAHs was different depending on the individual PAH.