Electro-Kinetic Enhanced Air Sparging Soil Remediation Process under Non-Ideal Conditions
Loretto Araya-Vicentelo, University Catolica del Norte, Avda Angamos 0610, Antofagasta, Chile, Mario A. Oyanader, Universidad Catolica del Norte, Avenida Angamos, Antofagasta, 0610, Chile, and Pedro E. Arce, Department of Chemical Engineering, Tennessee Tech University, Prescott Hall Room 214, Cookeville, TN 38505.
EK soil remediation has been identified as a versatile technology that can be applied to remove heavy metals as well as hydrocarbons from contaminated soils; electrokinetic remediation can be seen as a competing technique to Air Sparging which is more frequently used for organic compound clean ups. However, the main focus of this research is the identification of potential enhancements of these two technologies working together. This contribution deals with a research effort targeting the modeling aspects of a model dynamic system in which Electro-kinetic and Air Sparging techniques work together for enhancing soil cleaning. In particular, the project deals with the four phases equilibrium among soil, NAPL, water and injected air that are present in the system. The non linear nature of the transient state mass balance model requires a rigorous numerical solution of the system. The differential model equations yield the concentration profile of the contaminant in vertical directions of the target soil. The effects of different induced pressure values (at the soil surface) on the concentration profile underground are illustrated. The change in the dynamic response of the system under the stress of the pressure indicates the progressive movement of air mass thru the porous media. The results are investigated and compared with those related to the electrokinetic-based cleaning and the best strategy for coupling the respective electrohydrodynamic and equilibrium phase equations has been used to identify the main potential problems in achieving successfully clean up goals. A economical feasibility analysis of the potential advantages of the combined processes will be performed.