Microwave-Induced Desalination via Direct Contact Membrane Distillation

Document Type

Article

Publication Date

1-2-2018

Abstract

Membrane distillation (MD) is emerging as an important desalination technology that can operate at relatively low temperatures and can handle high salt concentrations. In this Article, we present microwave-induced membrane distillation (MIMD) where microwave radiation is used to heat the saline water for MD. Pure water vapor flux from MIMD was compared to that generated by conventional heating, and the enhancement reached as high as 52%. Because of the higher dielectric constants, flux enhancement was more significant at high salinity, and the mass transfer coefficient at 150000 ppm was found to be nearly 99% higher than what was observed under conventional heating. Performance enhancement in MIMD was attributed to nonthermal effects such as the generation of nanobubbles, localized superheating, and breaking down of the hydrogen-bonded salt-water clusters. These effects were investigated using FTIR, ion mobility measurements, and dynamic light scattering. In addition, microwave heating consumed nearly 20% less energy to heat water to the same temperature. The combination of energy savings and higher flux represents a significant advancement over the state of the art for MD.

Identifier

85040039312 (Scopus)

Publication Title

ACS Sustainable Chemistry and Engineering

External Full Text Location

https://doi.org/10.1021/acssuschemeng.7b02950

e-ISSN

21680485

First Page

626

Last Page

632

Issue

1

Volume

6

Grant

CBET-1603314

Fund Ref

National Science Foundation

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