Travel-time based model of bioremediation using circulation wells

Vertical circulation wells can efficiently provide microorganisms with subs trates needed for enhanced bioremediation. We present a travel-time based a pproach for modeling bioreactive transport in a now field caused by a serie s of circulation wells. Mixing within the aquifer is due to the differences in sorption behavior of the reactants, Neglecting local dispersion, transp ort simplifies to a single one-dimensional problem with constant coefficien ts for each well. Recirculation is characterized by the discharge densities over travel time. We apply the model to the stimulation of cometabolic dec hlorination of trichloroethene (TCE) by alternate injection of oxygen and t oluene into the circulation wells. Mixing within the wells can be minimized by interposing sufficiently long breaks between the oxygen and toluene pul ses. In our simulation, the proposed injection scheme stimulates biomass gr owth without risking biofouling of the aquifer.