Negative pressure membrane distillation for excellent gypsum scaling resistance and flux enhancement

Liu, Y., Horseman, T., Wang, Z., Arafat, H. A., Yin, H. , Lin, S. and He, T. (2022) Negative pressure membrane distillation for excellent gypsum scaling resistance and flux enhancement. Environmental Science and Technology, 56(2), pp. 1405-1412. (doi: 10.1021/acs.est.1c07144) (PMID:34941244)

Abstract

Membrane distillation (MD) has potential to become a competitive technology for managing hypersaline brine but not until the critical challenge of mineral scaling is addressed. The state-of-the-art approach for mitigating mineral scaling in MD involves the use of superhydrophobic membranes that are difficult to fabricate and are commercially unavailable. This study explores a novel operational strategy, namely, negative pressure direct contact membrane distillation (NP-DCMD) that can minimize mineral scaling with commercially available hydrophobic membranes and at the same time enhance the water vapor flux substantially. By applying a negative gauge pressure on the feed stream, NP-DCMD achieved prolonged resistance to CaSO4 scaling and a dramatic vapor flux enhancement up to 62%. The exceptional scaling resistance is attributable to the formation of a concave liquid–gas under a negative pressure that changes the position of the water–air interface to hinder interfacial nucleation and crystal growth. The substantial flux enhancement is caused by the reduced molecular diffusion resistance within the pores and the enhanced heat transfer kinetics across the boundary layer in NP-DCMD. Achieving substantial performance improvement in both the scaling resistance and vapor flux with commercial membranes, NP-DCMD is a significant innovation with vast potential for practical adoption due to its simplicity and effectiveness.

• Item Type: Articles
• Additional Information: The research was partially supported by National Natural Science Foundation of China (nos. 21978315 and 52011530031), Newton Advanced Fellowship from Royal Society (no. NA170113), CAS International Collaboration (no. GJHZ2080), and US National Science Foundation (no. 1903685). We also thank the framework research consortium for partial financial support (RFBR no. 18-58-80031, NSFC no. 51861145313, DST IPN/7864, NRT no.116020, and CNPq/BRICS-STI-2-442229/2017-8).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Yin, Professor Huabing
• Authors: Liu, Y., Horseman, T., Wang, Z., Arafat, H. A., Yin, H., Lin, S., and He, T.
• College/School: College of Science and Engineering > School of Engineering > Biomedical Engineering
• Journal Name: Environmental Science and Technology
• Publisher: American Chemical Society
• ISSN: 0013-936X
• ISSN (Online): 1520-5851
• Published Online: 23 December 2021
• Copyright Holders: Copyright © 2021 American Chemical Society
• First Published: First published in Environmental Science and Technology 56(2): 1405-1412
• Publisher Policy: Reproduced in accordance with the publisher copyright policy