Current opportunities and challenges in membrane-based brine management

Abstract

This perspective attempts to critically assess the latest developments in membrane-based brine concentration (MBC), crystallization (MBCr), and valorization (MBV), which are essential to make desalination more sustainable and to advance a more circular water economy. Herein, we examine membrane distillation, forward osmosis, electrodialysis, osmosis-assisted reverse osmosis, low-salt rejection reverse osmosis, and ultra-high-pressure reverse osmosis as emerging MBC technologies and compare them to each other and state-of-the-art thermal brine concentration. We discuss the implications and operational challenges of these technologies in minimal and zero liquid discharge applications. We further discuss various MBCr and MBV research efforts from the peer-reviewed literature and offer some perspective on what is likely needed to advance MBC, MBCr, and MBV approaches to commercial status.