DUAL-DOMAIN MASS TRANSFER

Solute transport in fractured media or extremely heterogeneous porous media may be conceptualized as a dual-domain system

Most of the transport is by advection through the fractures or zones of high hydraulic conductivity in the non-fractured matrix, transport is primarily by diffusion through the low hydraulic conductivity zones

As the dual-domain mass transfer rate (exchange between the mobile and immobile domains) increases, the dual-domain model is more similar a single-domain model with effective porosity near the total porosity of the entire medium

As the dual-domain mass transfer rate approaches zero, the model approaches a single-domain model with effective porosity near the porosity of the mobile domain

Read the MT3D manual for more specifics