Wetting phenomena in membrane distillation: Mechanisms, reversal, and prevention

Mohammad Rezaei; David M Warsinger; John H Lienhard V; Mikel C Duke; Takeshi Matsuura; Wolfgang M Samhaber

doi:10.1016/j.watres.2018.03.058

Wetting phenomena in membrane distillation: Mechanisms, reversal, and prevention

Water Res. 2018 Aug 1:139:329-352. doi: 10.1016/j.watres.2018.03.058. Epub 2018 Mar 30.

Authors

Mohammad Rezaei¹, David M Warsinger², John H Lienhard V³, Mikel C Duke⁴, Takeshi Matsuura⁵, Wolfgang M Samhaber⁶

Affiliations

¹ Institute of Process Engineering, Johannes Kepler University Linz, Altenberger Strasse 69, 4040 Linz, Austria. Electronic address: mohammad.rezaei@jku.at.
² Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA; Rohsenow Kendall Heat Transfer Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge MA 02139-4307, USA.
³ Rohsenow Kendall Heat Transfer Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge MA 02139-4307, USA.
⁴ Institute for Sustainability and Innovation, College of Engineering and Science, Victoria University, Melbourne, Victoria 8001, Australia.
⁵ Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
⁶ Institute of Process Engineering, Johannes Kepler University Linz, Altenberger Strasse 69, 4040 Linz, Austria.

PMID: 29660622
DOI: 10.1016/j.watres.2018.03.058

Abstract

Membrane distillation (MD) is a rapidly emerging water treatment technology; however, membrane pore wetting is a primary barrier to widespread industrial use of MD. The primary causes of membrane wetting are exceedance of liquid entry pressure and membrane fouling. Developments in membrane design and the use of pretreatment have provided significant advancement toward wetting prevention in membrane distillation, but further progress is needed. In this study, a broad review is carried out on wetting incidence in membrane distillation processes. Based on this perspective, the study describes the wetting mechanisms, wetting causes, and wetting detection methods, as well as hydrophobicity measurements of MD membranes. This review discusses current understanding and areas for future investigation on the influence of operating conditions, MD configuration, and membrane non-wettability characteristics on wetting phenomena. Additionally, the review highlights mathematical wetting models and several approaches to wetting control, such as membrane fabrication and modification, as well as techniques for membrane restoration in MD. The literature shows that inorganic scaling and organic fouling are the main causes of membrane wetting. The regeneration of wetting MD membranes is found to be challenging and the obtained results are usually not favorable. Several pretreatment processes are found to inhibit membrane wetting by removing the wetting agents from the feed solution. Various advanced membrane designs are considered to bring membrane surface non-wettability to the states of superhydrophobicity and superomniphobicity; however, these methods commonly demand complex fabrication processes or high-specialized equipment. Recharging air in the feed to maintain protective air layers on the membrane surface has proven to be very effective to prevent wetting, but such techniques are immature and in need of significant research on design, optimization, and pilot-scale studies.

Keywords: Hydrophobicity; Membrane distillation; Membrane modification; Membrane wetting; Pretreatment; Review.

Publication types

Review

MeSH terms

Distillation / instrumentation*
Distillation / methods
Membranes, Artificial*
Models, Theoretical
Water Purification / instrumentation*
Water Purification / methods
Wettability

Substances

Membranes, Artificial