Haffert, Laura; Haeckel, Matthias (2018): TRACTION - a transport reaction model specifically designed to account for non-ideal transport and reaction effects [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.894719,

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Supplement to: Haffert, L; Haeckel, M (2019): Quantification of non-ideal effects on diagenetic processes along extreme salinity gradients at the Mercator mud volcano in the Gulf of Cadiz. Geochimica et Cosmochimica Acta, 244, 366-382, https://doi.org/10.1016/j.gca.2018.09.038

Presented is an example of the transport-reaction code (TRACTION) applied to the simulation of pore water species in the seawater mixing zone at Mercator Mud volcano in the Gulf of Cadiz. TRACTION was specifically designed to account for non-ideal transport effects in the presence of thermodynamic (e.g. salinity or temperature) gradients. The model relies on the most fundamental concept of solute diffusion, which states that the chemical potential gradient (Maxwell's model) rather than the concentration gradient (Fick's law) is the driving force for diffusion. In turn, this requires accounting for species interactions by applying Pitzer's method to derive species chemical potentials and Onsager coefficients instead of using the classical diffusion coefficients. Electrical imbalances arising from varying diffusive fluxes in multicomponent systems, like seawater, are avoided by applying an electrostatic gradient as an additional transport contribution.