A Framework to Design and Optimize Surfactant-Enhanced Aquifer Remediation

摘要

Surfactant enhanced aquifer remediation has become anacceptable remediation technology to remove groundwatercontaminants such as petroleum hydrocarbons andchlorocarbons. There have been several recent fielddemonstrations of surfactant remediation where surfactants areused to significantly increase the solubility of the nonaqueousphase liquid (NAPLs) in water. The success of these tests wasdue to a unified approach using site characterization coupledwith a laboratory screening followed by 3D modeling of theprocess for design and optimization purposes.Here we present the design aspects of the subsurfacesurfactant flood with the emphasis on the flow and transportmodeling. The University of Texas numerical model UTCHEMwas used for this purpose. UTCHEM is a three-dimensional,multiphase, multicomponent chemical compositional simulatorcapable of modeling NAPL migration and groundwater flow andtransport in aquifers. Simulations are performed to determinetest design variables. These include wellfield configuration andrates, duration of injection and composition of surfactantsolution, and hydraulic control achievement using hydrauliccontrol wells.We illustrate an approach to design and optimizesurfactant-enhanced aquifer remediation processes in asystematic and efficient manner. To make the approach efficient, a framework that can distribute multiple numericalsimulations on a cluster of processors has been successfullyimplemented. This framework integrates a chemical-enhancednumerical model, UTCHEM, an experimental designmethodology, and a Monte Carlo algorithm with a robust globaloptimization search engine to identify the optimal combinationunder conditions of uncertainty.