Separation and Purification Technology, Vol.156, 480-488, 2015
Effective decontamination of low dielectric hydrocarbon-polluted soils using microwave heating: Experimental investigation and modelling for in situ treatment
This work aims to obtain essential data for the in situ application of microwave (MW) heating for hydrocarbon-polluted soil remediation. For this purpose, lab-scale experiments were performed and a dedicated computer code was developed and applied to simulate the phenomena induced by a MW treatment. MW process was modelled by means of the mono-dimensional transient equations of energy taking into account the interaction between the electromagnetic field and soil and conductivity phenomena. The model was validated by comparison with results from lab-scale experiments. Main results indicate that, after a MW irradiation of 6 days, the electric field was reduced by about one third of its initial value at a distance of 60 cm and, as a consequence, soil temperatures equal to and lower than 180 degrees C were observed. Overall, the thermal effect of the MW treatment was observed to affect a maximum distance of about 120 cm, and this allows the achievement of the contaminant removal in the range 50-99% for a maximum distance of 80 cm from MW source. Results are of scientific and practical interest and can be used to guide the design of in situ MW treatments. The proposed model provides good prediction of the experimental data and it can be applied to investigate further operating conditions (soil types, incident electric field applied, remediation time). It represents a powerful and suitable tool to predict the effectiveness of the MW techniques. (C) 2015 Elsevier B.V. All rights reserved.