REMEDIACIÓN ELECTROCINÉTICA DE UN SUELO REAL CONTAMINADO CON PLOMO ASISTIDA CON LA ADICIÓN DE UN AGENTE COMPLEJANTE

• Autor(a) principal: Villen-Guzman,Maria
• Data de Publicação: 2020
• Outros Autores: Cerrillo-Gonzalez,Maria del Mar, Paz-Garcia,Juan M., Vereda-Alonso,Carlos, Gomez-Lahoz,Cesar, Rodriguez-Maroto,Jose M.
• Tipo de documento: Artigo
• Idioma: spa
• Título da fonte: Química Nova (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422020000801078
• topic: electrokinetic; soil remediation; lead; complexing agent; sacrificial anode

The use of ethylenediaminetetraacetic acid disodium salt (Na2EDTA) as a chelating agent presents ideal characteristics to be used for the removal of lead from a contaminated site. Batch experiments together with a simple local equilibrium model were carried out to evaluate the role of EDTA as enhancing agent in electrokinetic remediation of a Pb-contaminated soil. According to preliminary results, Pb removal was close to 85% after 9 hours. Hence, electrokinetic experiments were designed implementing a pH control system at both electrode-compartments. From first experiments, no important Pb recovery was obtained probably due to the counteracting effect of the electroosmotic and electromigration movement of Pb-species. The use of an iron anode instead of a platinum anode involved the recovery of a high percentage of Pb (80%) at the cathode. These results were associated with the behavior of the iron as a sacrificial anode. Furthermore, the formation of Fe(EDTA)- hinders the formation of Pb(EDTA)2-, which entails the dissolution of the contaminant as Pb2+. Therefore, the Pb species are transported toward the cathode by electromigration and electroosmosis. Furthermore, the competition between the oxidation of iron and the water electrolysis entailed a lower consumption of NaOH to control pH value at the anode compartment.