Multicomponent mass transport modeling of water desalination by reverse osmosis including ion pair formation

Reverse Osmosis (RO) is one of the main membrane technologies currently used for desalination seawater and brackish water to produce freshwater. However, mechanism transport separation ions in RO membranes not yet fully understood. Besides acid–base reactions (i.e., including H+-ion), at high concentrations, salt can associate form ion pairs. In this study, we investigate how include formation these pairs extended Donnan steric partitioning pore model. We study a source where three be formed (NaCl, MgCl+, MgCl2) also self-dissociation carbonate system. The model assumes infinitely fast reactions, which means that participating are locally chemical equilibrium with another. A square stoichiometric reaction matrix composed active species, moieties, formulated. As final constraint equation, use charge balance. predicts profiles concentration, flux, rates across all species calculates retention per group ions. Ion pair has an influence on fluxes individual therefore influences