Design Considerations and Economics of Emerging Membrane Brine Concentration Processes

This paper addresses important design considerations for emerging membrane brine concentration processes, with specific focus on osmotically-assisted reverse osmosis (OARO). These processes are assessed on the basis of total cost of water over a range of brine TDS levels. For example, anticipated performance from modeled systems, validated with field testing, indicates that SWRO brine can be desalinated at 50% recovery, producing high-quality permeate at a specific cost of as little as $0.60/m3. The prospect of low costs combined with the broad market acceptance of membrane desalination methods portend a shift away from thermal brine concentration, in the same way that SWRO displaced MSF and MED for seawater desalination, while opening new opportunities for the application of membrane technologies.