Development and Application of a Mathematical Model for the Assessment of the Treatability of Radionuclides Polluted Soils by Microwave Heating Stabilisation: Preliminary Results

Abstract

Radionuclides polluted soils represent a major concern for environment and their remediation or stabilization are a key factor for human health. In recent years, treatments by MW heating have attracted great attention in environmental field, since it represents a novel and optimal approach for removal or stabilisation of organic pollutants and/or heavy metals. Therefore, in situ MW heating could represent an optimal choice for radionuclides polluted soils stabilisation. A huge effort has been made by several scientists in order to demonstrate MW applicability by means of lab-scale experiments, but very limited results were shown by pilot or full-scale activities, making unclear the limits and therefore the real applicability of in situ MW interventations. This lack makes essential the development of specific tools to plan full-scale MW treatments, in particular when large polluted soils volumes are involved. In this work a mathematical model was developed and applied to understand the effects of a long period MW radiation on the variability of several physical soil parameters. For simulating, a treatment time of 1 month, a maximum investigated distance from the microwave source (antenna) of 4 m and a power of 4 kw for the microwave generation at 2.45 GHz were applied. Preliminary results showed that in situ MW remediation of radionuclides polluted sandy soil is applicable for a limited distance of about 50 cm from the antenna and for a remediation time of 30 days. Powers higher than 4 kW or remediation time longer than 1 month should be investigated in order to successfully treat radionuclides polluted soils.