Permeowa

Permeowa is a term used in some theoretical discussions of porous-media transport to denote a dimensionless parameter that combines permeability with sorption effects. It is intended to describe how a permeant moves through a solid matrix when adsorption and desorption at pore walls influence transport, in addition to viscous flow and diffusion through the pore network.

Permeowa is conceived as a coupling quantity in generalized transport equations. It captures how sorption capacity, pore-size distribution, and membrane morphology modify the net flux beyond what simple Darcy or Fick laws predict.

The term emerged in the early 2020s within environmental engineering, materials science, and geosciences as a shorthand for coupled transport phenomena. It is not part of formal standards and lacks a universal experimental definition; researchers treat permeowa as a modeling parameter whose interpretation may vary by context.

Estimation is typically done by fitting transport data (pressure-driven flux, concentration profiles, or sorption isotherms) to a coupled-transport model. Accurate characterization of porosity, intrinsic permeability, sorption isotherms, and diffusion coefficients is required, along with attention to anisotropy and time dependence.

If adopted, permeowa could aid material screening in applications such as activated carbons, polymer membranes with sorptive additives, and natural geological formations where sorption strongly affects flow. However, its use remains limited and context-dependent due to definitional variability and lack of standard methods.

See also: Permeability, Diffusion, Sorption, Porous media.