Optimization Of Mercury Remediation From A Contaminated Industrial Park Soil Via Thermo Desorption: An Experimental Approach

Extended Abstract Environmental contamination caused by mercury - due to its mobility and long residence time in the soil and atmosphere [1] - is an emerging problem worldwide [2]. To treat and remove the contaminant from the soil, different techniques have been implemented, both in laboratory, pilot and full-scale applications. One of the most promising approach for mercury removal is thermal desorption, a treatment technology that utilizes heat to increase the volatility of contaminants which are subsequently removed from the solid matrix and treated in an off-gas treatment system [3]. In this work we analysed and treated a soil from an industrial area with high levels of mercury contamination, mostly in the forms of elemental mercury (24-67%) and insoluble inorganic mercury (32-73%). To understand the most effective remediation strategy, a series of tests have been performed on a different number of soil samples. The soil was collected via core drilling up to a depth of 5 metres, and each 1 metre layer was characterized in terms of total mercury contamination, dry residue, humidity, sieve fraction (less than 2 cm and more than 2 mm), and a mercury speciation was performed. After a first characterization, the layer with the highest mercury contamination was identified and 10 kg of material was selected for the subsequent analysis. A composite sample was obtained via mixing of the whole layers cored, including the high polluted stratum, and 30 kg of material was collected for analysis. A series of laboratory tests were performed on the samples from both the most