Application of the electrokinetic-Fenton process for the remediation of kaolinite contaminated with phenanthrene

Abstract

This study explored the feasibility of applying the electrokinetic-Fenton process (EK-Fenton process) for the remediation of contaminant sorbed onto soil possessing low-permeability. The relationship of H 2O 2 stability and phenanthrene treatment, and the variation in the monitoring values were also investigated during the EK-Fenton process when catalyzed by heterogeneous minerals. Phenanthrene was chosen to represent hydrophobic organic contaminants (HOCs), which are widespread in the environment, and kaolinite was used as the low-permeability soil. In these experiments, the H 2O 2 concentrations in pore water, the electrical potential distributions and the electrical currents were measured or monitored to assess the electrochemical effect in relation to injections of H 2O 2 from the anode. The results suggested that intermediate anions (HO 2 −, O 2 −) with Fenton-like reaction affected significantly the variations in the electrical current during the EK-Fenton process. The addition of 0.01 N H 2SO 4 to the anode reservoir improved the H 2O 2 stability and the treatment of phenanthrene in the entire soil specimen. Therefore, use of H 2O 2 and dilute acid, as an anode purging solution is a possible method for treating HOCs in low-permeability subsurface environments.