Journal of Hazardous Materials 177 (2010) 1–11 Contents lists available at ScienceDirect Journal of Hazardous Materials journal homepage: www.elsevier.com/locate/jhazmat Review Decontamination of soils containing PAHs by electroremediation: A review M. Pazos ∗ , E. Rosales, T. Alcántara, J. Gómez, M.A. Sanromán Department of Chemical Engineering, University of Vigo, E-36310 Vigo, Spain article info Article history: Received 17 September 2009 Received in revised form 28 October 2009 Accepted 8 November 2009 Available online 13 November 2009 Keywords: Electroremediation PAHs Decontamination Soil Review abstract During the last years, the anthropogenic sources have contributed to organic compound penetration into the environment. One large group of persistent and toxic contaminants is the hydrophobic organic contaminants. Among them, polycyclic aromatic hydrocarbons (PAHs) have been recognized as a repre- sentative group of these pollutants with low solubility. In this paper, it is showed the electroremediation of soil contaminated with PAHs as an alternative, to organic compound removal. This technique, mainly used for heavy metal extraction, applies the electric current to promote the movement of contaminants. Nowadays the application of this technique alone or combined with other techniques as for example Fen- ton or bioremediation is taking fine results to PAHs removal. Although the PAHs soil decontamination by means of the electric field is in an initial stage, many researchers have demonstrated the treatment effectiveness. This paper describes the foremost principles to carry out the electroremediation of soils contaminated with PAHs, just like the different alternatives to improve the electroremediation of PAHs and also the new methodologies of PAHs removal by using hybrid technologies. © 2009 Elsevier B.V. All rights reserved. Contents 1. Introduction .......................................................................................................................................... 1 2. PAHs soil contamination ............................................................................................................................. 3 3. Electroremediation to PAHs soil decontamination .................................................................................................. 4 3.1. Electroremediation principles ................................................................................................................ 4 3.2. Electroremediation with solubilising agents ................................................................................................. 4 3.2.1. Co-solvents ......................................................................................................................... 4 3.2.2. Surfactants .......................................................................................................................... 6 3.2.3. Cyclodextrins ....................................................................................................................... 7 3.3. Hybrid technologies .......................................................................................................................... 8 3.3.1. Electro-Fenton ...................................................................................................................... 8 3.3.2. New approaches .................................................................................................................... 9 4. Conclusions .......................................................................................................................................... 9 Acknowledgements .................................................................................................................................. 9 References ........................................................................................................................................... 9 1. Introduction During the last years, the anthropogenic sources have con- tributed to organic compound penetration into the environment. One large group of persistent and toxic contaminants is the hydrophobic organic contaminants (HOCs), and, obviously, the main characteristic that differentiates these pollutants from other ∗ Corresponding author. Tel.: +34 986 812304; fax: +34 986 812380. E-mail address: mcurras@uvigo.es (M. Pazos). contaminants is their hydrophobicity, they are repelled from water [1]. In addition, these substances tend to exist as pockets at the soil subsurface location to which they have migrated [2]. From a technical point of view, it is particularly difficult to treat or remove contaminants possessing low water solubility and high octanol–water partition coefficients characteristics [3]. Further- more, some environmental factors as soil type and structure, pH, temperature and the association with co-pollutants such as other hydrocarbons and/or heavy metals, can prolong their time in the environment [4]. New technologies are being developed to mobilize or solubilise these contaminants in order to improve 0304-3894/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.jhazmat.2009.11.055