HR: 0830h
AN: H11G-0923    [PDF]
TI: Numerical Investigation of the Influence of Aquifer Heterogeneity, Reaction Kinetics, and Treatment Solution Strength on Permanganate Remediation Efficiency
AU: * Henderson, T H
EM: thenderson@eos.ubc.ca
AF: Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, BC V6T 1Z4 Canada
AU: Mayer, K U
EM: umayer@eos.ubc.ca
AF: Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, BC V6T 1Z4 Canada
AU: Parker, B L
EM: blparker@sciborg.uwaterloo.ca)
AF: Department of Earth Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON N2L 3G1 Canada
AU: Al, T A
EM: tal@unb.ca
AF: Department of Geology, University of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3 Canada
AU: Cherry, J A
EM: cherryja@uwaterloo.ca
AF: Department of Earth Sciences, University of Waterloo, 200 University Ave. W., Waterloo, ON N2L 3G1 Canada
AB: Numerical models have been developed simulating the chemical oxidation of the chlorinated solvent tetrachloroethylene using potassium permanganate. The remediation methodology modeled is the passive injection method in which the oxidant is injected to targeted locations above accumulations of dense non-aqueous phase liquids (DNAPLs) using a driven well point. Downward movement and spreading of the oxidant is caused by the initial injection pressure and by the density contrast with the groundwater. The coupled fluid flow, chemical transport, and chemical reaction equations are solved using a combination of the global implicit method and a Picard iterative scheme. The former is applied to the solution of the chemical transport and reaction equations, while the groundwater flow and chemical transport/reaction equations are solved sequentially until convergence is achieved. A partial equilibrium approach is used to model the geochemical reactions resulting from the oxidant injection. Reaction rate expressions for DNAPL dissolution and permanganate oxidation were developed based on the results of previously completed column experiments. Two and three-dimensional simulations were performed to assess the sensitivity of DNAPL destruction efficiency to oxidant concentration, reaction kinetics, and media heterogeneity. Random spatially correlated hydraulic conductivity fields were generated based on the statistical parameters of the Borden aquifer. Model results indicate that remediation efficiency was affected by solution strength, which controls the ability of the oxidant to reach the contaminant. The simulations also indicate that destruction efficiencies were insensitive to the reaction kinetics, suggesting that the DNAPL dissolution and oxidation reactions were transport controlled.
DE: 1010 Chemical evolution
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2003 Fall Meeting