Amongst totally different desalination applied sciences to deal with freshwater demand, membrane distillation (MD) is promising in that it could possibly successfully deal with hypersaline feed or reverse osmosis reject and additional enhance freshwater restoration whereas concurrently decreasing the quantity of liquid discharge. Nonetheless, wetting of membrane pores by surfactant compromises separation effectivity since MD depends on sustaining a secure air hole within the membrane pore. The kinetics of surfactant-induced wetting for a hydrophobic membrane utilized in MD know-how have been proven to rely solely on bulk surfactant focus and vapour flux. On this examine, we look at the decoupled impact of salt focus and bulk surfactant focus and its relation to surfactant-induced wetting. Even at low surfactant focus (0.1 mM sodium dodecyl sulphate), the focus of salt (sodium chloride) can considerably have an effect on wetting dynamics. Specifically, excessive salt concentrations (above 1.2 M or 70 g/L NaCl) can notably speed up wetting, and thereby render MD unsuitable for such feeds. However, surfactant concentrations properly above essential micelle focus (CMC) are examined with low salt focus, and outcomes reveal that hydrophobic PVDF membranes carry out fairly stably with none vital loss in salt elimination effectivity. A mathematical framework that captures ionic power and surfactant exercise can also be proposed to foretell totally different membrane wetting regimes. These findings level to the necessity for coupling bulk surfactant focus with salt focus to foretell surfactant-induced wetting extra precisely. These outcomes additionally open an avenue for another mechanism that enhances the present understanding of surfactant-induced wetting.
