The in situ chemical oxidation (ISCO) is a technology that requires injecting an oxidant into the ground, in order to treat organic pollutants (present in the soil matrix, or possibly in the groundwater). A specific oxidant is chosen evaluating laboratory tests where the reactivity between the organic pollutants (targets) and the oxidant is assessed; concerning the area to be remediated, pre-treatment investigations are generally limited to the determination of pollutants distribution into the site, the characterization of the latter being realized through geological, topographical and hydrodynamic studies. Both an appropriate distribution of the oxidant in the subsurface, which must cover the entire impacted area, and the total amount of oxidant to be used are essential factors, deciding of the effectiveness of the approach to the field. In the traditional application scheme, the recourse to ISCO is usually limited to soils having medium to high permeability, and where the chemical oxidant demand is limited. Typically, the ISCO technology is applied to fields of prevalently sandy or gravelly character; however, if the matrix is characterized by a chemical oxidant demand much greater than that of polluting targets, the ISCO remediation does not appear to be feasible. The possibility of assisting the ISCO technology using an electrokinetic treatment, aiming at mobilizing the oxidant in soils with low permeability, through phenomena such as electromigration and electroosmotic flow, will be discussed. Besides, laboratory tests have shown that the application of an electric field can lead to a reduction of the aforementioned chemical oxidation demand of the soil, as well as of the concentration of halogenated pollutants (a phenomenon merely mentioned in the literature, and to whom the name of “in situ electro oxidation”, ISEO, was given). To deal with soils having a high chemical oxidation demand, a preliminary ISEO treatment may then allow the subsequent application of ISCO.
RECLAMATION OF SOILS CONTAMINATED BY CHLORINATED ORGANICS: RESULTS FROM ELECTROOXIDATION TESTS
ROSESTOLATO, Davide;FERRO, Sergio;DE BATTISTI, Achille;
2011
Abstract
The in situ chemical oxidation (ISCO) is a technology that requires injecting an oxidant into the ground, in order to treat organic pollutants (present in the soil matrix, or possibly in the groundwater). A specific oxidant is chosen evaluating laboratory tests where the reactivity between the organic pollutants (targets) and the oxidant is assessed; concerning the area to be remediated, pre-treatment investigations are generally limited to the determination of pollutants distribution into the site, the characterization of the latter being realized through geological, topographical and hydrodynamic studies. Both an appropriate distribution of the oxidant in the subsurface, which must cover the entire impacted area, and the total amount of oxidant to be used are essential factors, deciding of the effectiveness of the approach to the field. In the traditional application scheme, the recourse to ISCO is usually limited to soils having medium to high permeability, and where the chemical oxidant demand is limited. Typically, the ISCO technology is applied to fields of prevalently sandy or gravelly character; however, if the matrix is characterized by a chemical oxidant demand much greater than that of polluting targets, the ISCO remediation does not appear to be feasible. The possibility of assisting the ISCO technology using an electrokinetic treatment, aiming at mobilizing the oxidant in soils with low permeability, through phenomena such as electromigration and electroosmotic flow, will be discussed. Besides, laboratory tests have shown that the application of an electric field can lead to a reduction of the aforementioned chemical oxidation demand of the soil, as well as of the concentration of halogenated pollutants (a phenomenon merely mentioned in the literature, and to whom the name of “in situ electro oxidation”, ISEO, was given). To deal with soils having a high chemical oxidation demand, a preliminary ISEO treatment may then allow the subsequent application of ISCO.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
