Soil remediation by an advanced oxidative method assisted with ultrasonic energy

A new process for the remediation of soil contaminated with hydrocarbons is proposed. The innovation consists on coupling an advanced oxidative method, using a Fenton-type catalyst, with the application of ultrasonic energy. The use of ultrasonic energy not only assists the desorption of the contaminants from the soil, but also promotes the formation of (OH)-O-center dot radicals, which are the oxidant agents involved in the oxidation process. Different Fenton-like catalysts were employed in the present study; however, the highest removal of toluene and xylenes were obtained with iron sulfate and copper sulfate, respectively. Also, hydrogen peroxide was tested at different concentrations, and it was found that increasing its concentration enhanced the removal of all the contaminants. Finally, it was demonstrated that applying ultrasonic energy to the reacting system process noticeably enhanced the global efficiency of the process due to a synergistic effect in conjunction with the hydrogen peroxide concentration and type of catalyst. (c) 2006 Elsevier B.V. All rights reserved.