title: Equilibrium approaches to organic contaminant transport modeling in a multi-phase groundwater system.
abstract: Mathematical models were developed in this study based on equilibrium sorption approaches to simulate transport and retardation of organic contaminants such as polycyclic aromatic hydrocarbons in a multi-phase groundwater system. In a model development, the Langmuir or Freundlich sorption isotherms were incorporated into a retardation factor to account for nonlinear sorption of contaminants and colloids on solid matrix. Numerical solutions of model equations were obtained using a fully implicit finite difference method. Simulation results showed that the contaminant retardation factor varied temporally and spatially in a multi-phase system (dissolved phase, solid phase, and two mobile colloidal phases). Simulation also indicated that colloidal concentration and mobility would be key factors in controlling the contaminant transport in a multi-phase system. Sensitivity analysis demonstrated that the models were sensitive to changes of nonlinear isotherm coefficients and equilibrium distribution coefficients.
authors.affiliation: School of Biological Resources and Materials Engineering, Seoul National University, Seoul 151-742, Korea.
authors.forename: S B
authors.initials: SB
authors.lastname: Kim
mesh_terms: D003102:Colloids; D008962:Models, Theoretical; D009930:Organic Chemicals; D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants / Q000032:analysis*; D014872:Water Movements; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D003102:Colloids; D009930:Organic Chemicals; D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants; D014873:Water Pollutants