XtremeRO & OARO —Membrane Brine Concentrators

Advanced reverse osmosis, nanofiltration and osmotically assisted reverse osmosis (OARO) systems for demanding industrial applications

Our next-generation reverse osmosis (RO) and nanofiltration (NF) systems provide industry-leading recovery and reliability—concentrate brine and reduce discharge volumes, recover freshwater, separate divalent and monovalent salts, and reduce the size and cost of downstream thermal brine management systems.

Next-Generation Membrane Concentrators

Reverse Osmosis (RO) — the world’s dominant desalination technology — uses pressurized, semi-permeable membranes to remove dissolved salts from water. Nanofiltration (NF) uses a slightly more porous membrane and can separate divalent and monovalent dissolved ions.


RO should be considered first in all industrial wastewater and desalination applications as the primary water recovery device for its scalability and lower cost than thermal systems. NF has specialty applications like softening or purifying monovalent salts such as lithium, sodium, and chloride.


Recent technological improvements allow RO and NF to achieve higher freshwater recoveries, reduce brine volumes, and treat more challenging waters such as those with scalants and organics. Ultra-high pressure RO (UHP-RO) membranes can reach brine concentrations of up to 130,000 mg/L total dissolved solids (TDS). Osmotically assisted reverse osmosis (OARO) systems elevate brine concentration capabilities to 200,000 mg/L by cascading RO circuits with salt-permeable membranes in the final stage(s).


Scaling ions and foulants must be controlled to protect RO and NF membrane health, alongside sound hydraulic engineering and digitized diagnosis and self-cleaning. Saltworks offers systems for all of the above.       

Photo of reverse osmosis vessels in a Saltworks XtremeRO plant
Photo of a Saltworks advanced membrane desalination pilot treating cooling tower blowdown at a customer site
An XtremeRO on-site pilot that achieved 99% recovery on cooling tower blowdown

Minimal Liquid Discharge (MLD) Systems

Saltworks is experienced with complex chemistries and membrane fundamentals—having pioneered in the field of membrane brine concentrators. We offer tight integration with our full suite of advanced technologies to maximize recovery, minimize fouling risk, and enhance membrane longevity and overall reliability and uptime.


Our BrineRefine and XtremeUF platforms remove scaling ions such as silica and calcium, thereby enabling RO recoveries to reach osmotic pressure limits.  The selection of RO operating pressure or OARO varies with brine concentration goals.   

Saltworks Membrane Concentrator systems are available in four pressure classes:

  • XtremeRO 600 operates at 600 psi (41 bar), concentrates brine to ~40,000 mg/L TDS
  • XtremeRO 1200 operates at 1,200 psi (80 bar), concentrates to 80,000 mg/L TDS
  • XtremeRO 1800 (UHP-RO) operates at 1,800 psi (120 bar), concentrates brine up to 130,000 mg/L TDS
  • OARO offers the next level of brine concentration built around commercially available spiral wound membranes and can concentrate brines up to 200,000 mg/L TDS

Saltworks’ packages these unit operations into a total minimal liquid discharge (MLD) solution — fully packaged, automated, scalable, and ready-to-operate. We incorporate intelligent automation and self-diagnostics that maintain membrane health, maximize up-time, and minimize operating costs and design systems with the best RO or NF membranes for your project.

Membrane Concentrator Services

  • We provide a full suite of XtremeRO™ services to help you achieve the optimal solution for your project, including industrial desalination, brine treatment, volume reduction, lithium refining, and chemical recovery applications.

    • Initial consulting and technical advice to understand treatment options, residuals management, and balancing capital and operating costs.
    • Process design for maximum recovery and optimal integration with your other treatment process.
    • Engineering and design services to build and quality assure your full-scale plant.
    • Bench and pilot testing services, including mobile systems for rapid on-site deployment.
    • Comprehensive support including testing and remote monitoring.
    • R&D capability for unique applications.
Render of the vessel of a Saltworks XtremeRO reverse osmosis brine concentrator
Photo of XtremeRO and ultrafiltration skids with Saltworks' engineers

Start Your RO or NF Project

All systems are thoroughly factory-tested and delivered with comprehensive on-site commissioning, training, and support. We provide custom process design and engineering, including post-treatment options for specialized applications.


Take advantage of our comprehensive pilot testing program including mobile units ready for rapid dispatch. We can also set you up with remote operation capability, remote support for your operators, and spares management.


Contact us to get started on your project.

Related Resources

Photo of RO vessels in an XtremeRO plant

Ultra-High Recovery at Full-Scale: RO & EDR Plants Shipped

Saltworks is excited to announce the shipment of two ”competing” membrane-based industrial wastewater treatment plants. Although electrodialysis reversal (EDR) and reverse osmosis (RO) may be viewed as competing desalination technologies, Saltworks offers both and helps clients navigate the fit case for each.

A photo of a bank of reverse osmosis units at a public water utility plant.

RO Brine Treatment: Why Maximizing Reverse Osmosis Recovery Matters

Treating RO brine should be approached from two directions. First, maximize the recovery of lower cost membrane systems to minimize the volume for later steps. Second, weigh brine disposal options against thermal treatment technology to determine whether you need to concentrate your brine or treat it down to solids.