SIMULATING BIOREMEDIATION OF URANIUM-CONTAMINATED AQUIFERS ; UNCERTAINTY ASSESSMENT OF MODEL PARAMETERS

A time-dependent one-dimensional reactive transport model is developed with oxidation of organic carbon by microorganisms using O2,NO3, Mn, Fe and SO4.Presentation of the equations of a set of coupled mass balance accounting for advection, hydrodynamic dispersion , kinetic formulation of the biological or chemical transformation. Solving by finite difference method. Numerical solution procedure and computing of speciation -sorption and precipitation -dissolution of the species under equilibrium conditions, reactive transport equations., biotic-abiotic and redox reaction rate expressions. Model uncertainty assessment HDMR is presentedwith application of the fate and transport of uranium in the subsurface. Values of reaction parameters used in simulation , second-order rate coefficients for redox reactions are given. Discussions on simulated concentration profiles of terminal electron acceptors and reduced species after one year of biostimulation. Simulated concentration profiles of uranium after 1 year of biostimulation. Statistical analysis of numerical experiments to assess the dynamics of uranium in a saturated aquifer during bioremediation.