Scaling-up the acid-enhanced electrokinetic remediation of a real contaminated soil

• Electrokinetic remediation is feasible for the remediation of this soil.
• The BCR procedure is a tool for the prediction of the recoverable metal for each soil.
• A convenient specific energy can be defined after the BCR for each metal.
• The specific energy allows predictions for the energy requirement for each scale.

Although there is a lot of experimental work published about the use of Electrokinetic Remediation for the removal of toxic metals from soils, very few have reported results for different scales. Scaling-up is a difficult task, since the behavior of each metal is different and is also site-specific. In this paper we present a convenient parameter for the comparison of the energy requirements at different scales. This parameter consists on the definition of a specific-energy for each metal, based on the amount mobilized and the maximum removal expected as determined from the BCR fractionation analysis. The tests, which were carried out with soil columns holding soil samples of 16 g and with soil samples of 2000 g, are giving similar values of this parameter. Our results indicate that this specific-energy depends on the target metal to be recovered, but for each metal is quite similar for the experimental conditions of the two scales essayed. These conditions included that the initial electrical resistivity times the column length were equal for the two scales. A simple mathematical model predicts these results, and that for equal resistivity the specific energy requirement will be proportional to the distance between electrodes.