Enhanced Membrane Distillation Water Flux through Electromagnetism

Abstract Enhancing the efficiency of membrane distillation (MD) is crucial for implementing this desalination technology on a large scale for freshwater production. Herein, an interesting opportunity of enhancing membrane distillation performance by applying an external electromagnetic field to the feed stream is demonstrated. It has been proven that electromagnetic fields can affect water evaporation rate, which is primarily related to the effect of the electromagnetic field on the hydrogen bonds of water clusters. However, as of yet, the enhancement in MD performance through the assistance of electromagnetic fields has not been previously recognized. Herein, it is demonstrated that the permeate flux of membrane distillation can be increased by up to 10% through exposing the saline feed water to an external electromagnetic field (EMF). It was found that the presence of divalent ions in the feed solution during the application of EMF resulted in a higher increase in permeate flux than when only NaCl was present. The electromagnetic treatment is non-destructive to current MD and thus can be easily adapted to large-scale water desalination processes.