Temporal moment analysis of contaminant extraction: effects of flow heterogeneity and spatially variable source concentrations

The first and second temporal moments associated with the solute breakthrough curve resulting from contaminant extraction from a source region in a heterogeneous aquifer are investigated. A stochastic Lagrangian methodology is used to analyse the effects of flow heterogeneity, spatial variability in the initial concentrations within the source, and sorption kinetics characterized by uniform parameters. The results, obtained by first-order approximations of the variable parameters, indicate relatively small effects of spatial variability, except for the effect on the second moment at large desorption rates.