Semi-Analytical Modeling of Contaminant Migration and Degradation from Multiple Pollution Sources under Rate-Limited Sorption

Previous studies on contaminant transport models have primarily focused on boundary sources, limiting their applicability to scenarios with multiple internal pollution sources. This study develops a semi-analytical model for multispecies contaminant transport that incorporates advection, dispersion, rate-limited sorption, and first-order degradation, accommodating arbitrary time-dependent pollutant sources. By addressing rate-limited sorption, the model avoids underestimating degradable pollutant concentrations in non-equilibrium scenarios. The model is derived using the Laplace transform, finite cosine Fourier transform, generalized integral transform, and inverse transformations. Results highlight the sensitivity of contaminant and degradation product concentrations to time-dependent source variations. The model's key contribution lies in its ability to simulate dispersion from multiple internal sources under rate-limited sorption conditions, providing more accurate predictions of pollution plume dynamics and offering a robust alternative to boundary-source models for preliminary pollution management.