Cost Optimization of Low-Salt-Rejection Reverse Osmosis

Adam Atia, Jeff Allen, Ethan Young, Bernard Knueven, Timothy Bartholomew

Research output: Contribution to journalArticlepeer-review

15 Scopus Citations


Low-salt-rejection reverse osmosis (LSRRO) is an emerging membrane-based desalination technology for concentrating brines with potentially lower energy consumption and cost than thermally driven processes. We assess the technoeconomic performance of LSRRO by using an optimization model that minimizes the levelized cost of water (LCOW). We develop detailed models for the RO module and other equipment using WaterTAP (Water treatment Technoeconomic Assessment Platform), an open-source simulation and optimization software for water treatment. We improve upon previous LSRRO cost optimization studies by optimizing the salt permeability for each stage, which has significant implications for technoeconomic performance. We present the cost-optimal design, operation, and performance for three cases: 35 g/L TDS feed at 70 % recovery, 70 g/L at 55 %, and 125 g/L at 35 %. The cost-optimal LCOW and specific energy consumption (SEC) for these cases are 0.70, 1.89, and 7.41 $/m3 and 3.9, 8.4, and 30.4 kWh/m3, respectively. For each case, we use sensitivity analyses to provide guidance on key factors that impact economic viability. We also present the cost-optimal LCOW and SEC for feed concentrations between 5 and 220 g/L TDS and recoveries between 30 and 90 %. Lastly, we compare LSRRO to other high-salinity desalination technologies and find that it may be cost-competitive below feed concentrations of 125 g/L.

Original languageAmerican English
Article number116407
Number of pages14
StatePublished - 2023

Bibliographical note

Publisher Copyright:
© 2023

NREL Publication Number

  • NREL/JA-2C00-84452


  • Brine management
  • Cost optimization
  • High-salinity desalination
  • Minimal liquid discharge
  • Reverse osmosis


Dive into the research topics of 'Cost Optimization of Low-Salt-Rejection Reverse Osmosis'. Together they form a unique fingerprint.

Cite this