Study of electrochemical remediation of clay spiked with C12-C18 alkanes

Abstract

To date, the management of polluted soils and sediments is challenging because they can be characterized by heterogeneous conditions, miscellaneous contaminants (organic and inorganic ones), fine grains and low-hydraulic permeability. In these cases, the current treatment methods are poorly effective. ElectroChemical Remediation Technologies (ECRTs) are considered some of the main appealing strategies for the remediation of such complex sites. The ECRTs are based on the application of a relatively low cell potential value, between two or more electrodes, inducing an electric field (E) through the polluted media, which prompts the remediation of the contaminated site. This work was focused on the study of the electrochemical remediation of kaolin artificially spiked with a miscellaneous of five alkanes (C12H26, C13H28, C14H30, C16H34, C18H38), namely C12-C18. Kaolin was selected as a model reproducible, low-buffering, and low-permeability clay and the mixture C12-C18 as a hazardous model of petrol hydrocarbon compounds. The effect of several operative conditions, including the E intensity, type of technology, presence of supporting electrolyte, was investigated. It was found that adopted low E values can simultaneously mobilize and degrade in situ the C12-C18 mixture and that the shorten the chain compound, the easier the remediation efficiency, R.