Solute Transport and Biodegradation Characteristics for Models of Enhanced Subsurface Bioremediation
The analysis reveals that there are two important processes which control solute transport and biodegradation, namely, solute mixing that is enhanced by the retarded substrate velocity and localized nonlinear biodegradation that is limited to the mixing zone. The balanced interaction between these two processes causes the solute concentration fronts to travel downstream in unison (front coherence) and promotes the formation of traveling waves. If the acceptor is not consumed during microbial decay, the long-term biodegradation rate is a function only of the stoichiometric ratio of acceptor to substrate consumption, initial and input solute concentrations, and the depth-averaged groundwater flow velocity and retardation factor of the substrate. The microbial kinetic parameters, initial biomass concentration, dispersion parameters, and the spatial variation of the flow velocity and the retardation factor do not significantly affect the long-term biodegradation rate; these factors, however, control the biodegradation rate at a short elapsed time after acceptor injection. The theoretical analysis is also extended to study the effect of acceptor consumption during microbial decay and the minimum time required for these long-term characteristics to appear.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign