Stochastic analysis of oxygen- and nitrate-based biodegradation of hydrocarbons in aquifers

摘要: A Lagrangian stochastic framework was used to analyze field-scale aerobic biodegradation in a heterogeneous aquifer, using Monod-kinetics based reactions between the contaminant, oxygen and microbes. Subsurface heterogeneity represented by closed-form travel time distributions, derived from spatially correlated random hydraulic conductivity field with log-normal distribution. The solution coupled nonlinear, one-dimensional transport equations obtained operator-splitting technique. presence of nitrate, considering nitrate as second electron acceptor, produced significantly different results under intrinsic conditions for scales sorption. In general, acceptor can substantially lower peak contaminant concentration increase maximum remediation various There exists critical value retardation coefficients both microbes that produce complete degradation mass, this depends on availability acceptor(s) is independent heterogeneity. Maximum were sensitive half-saturation constants. Enhanced showed be increased approximately 15% when or 50%, but further may if injection occurred at more effective location. proposed methodology capable analyzing multiple acceptors simple computationally attractive manner, producing useful design parameters. key contributions arising analysis, its limitations potential approaches overcoming these are also discussed.