Korea Institute of Geoscience and Mineral Resources, Groundwater & Ecohydrology Research Center, Daejeon, South Korea

Speech Title: Generalized semi-analytical solutions to multi-species transport equation coupled with sequential first order reaction network with distinct retardation coefficients using GITT

Abstract: This paper presents a semi-analytical procedure for solving coupled the multispecies reactive solute transport using generalized integral transformation techniques (GITT), with a sequential first-order reaction network with distinct retardation coefficients. This proposed approach includes spatially or temporally varying flow velocities and dispersion coefficients, general initial conditions, and arbitrary temporal variable inlet concentration as well as distinct retardation values for all reactive species. This proposed approach sequentially calculates the concentration distributions of each species by employing the generalized integral transformation techniques, where spatially or temporally variable transport coefficient often encountered in a real field can be managed.

Specifically, traditional Laplace or Fourier transform methods cannot manage even single species transport problems with such arbitral spatial or temporal varying transport coefficients.

Since the proposed solutions for each species concentration distributions have separable forms in space and time, the solution for daughter species can be obtained using only the GITT by directly substituting solutions for the parent species into the transport equation of daughter species.

The proposed solutions were compared with previously published analytical solutions or numerical solutions of the numerical code of 2DFATMIC in some verification examples. In these examples, the proposed solutions were well matched with previous analytical solutions and numerical solutions obtained by 2DFATMIC.Although the approach outlined in this study was one-dimensional in nature, extension to multidimensional solution necessary to properly represent the case of prevailing anisotropic conditions or preferential flow conditions is straightforward.