Optimization of Energy Recovery in Brackish Water Reverse Osmosis Desalination Systems
Project ID: 1088
Principal Investigator: Steve Dundorf
Research Topic: Desalination and Water Treatment
Priority Area Assignments: 2011 (Advanced Water Treatment)
Funded Fiscal Years: 2010 and 2011
* What is the minimum energy cost possible for brackish water desalination using existing energy recovery technologies in an optimized total system?
* Is pilot scale system performance directly scalable to full scale?
Need and Benefit
There is a continuous need for less expensive water for potable and nonpotable sources produced with treatment systems that use less energy. This is especially the case for ocean and brackish water sources, which traditionally have been more expensive and energy intensive to treat. The ability to cost effectively treat brackish water sources will help alleviate water shortages in areas that have run out of fresh water sources and potentially reduce the demand for already water stressed sources such as the Colorado River.
A key factor in reducing desalination costs has been improved energy recovery devices such as the pressure exchanger. Energy recovery devices have often been restricted to seawater desalination, but existing pressure exchanger technology may have some substantial benefits when applied to brackish waters. The goal for this pilot test is to achieve a 15- to 30-percent reduction in energy use of brackish water treatment through the use of the pressure exchanger and some innovative flow regimes to increase recovery. It is important to evaluate energy recovery devices as a component of an entire reverse osmosis system and not as a stand alone unit. Increased water recovery will also help minimize additional brine treatment needed for zero liquid discharge scenarios.
A part of ensuring advanced treatment options are used and high quality water is produced at a more affordable cost is ensuring that those involved in water treatment know the actual costs of the technology.
Independent Peer Review
The following documents were reviewed by qualified Bureau of Reclamation employees. The findings were determined to be achieved using valid means.
Optimizing Brackish Water Reverse Osmosis for Affordable Desalination (final, PDF,
By Mr. Bradley Sessions, Ms. Wen-Yi Shih, John MacHarg, Steve Dundorf and Mr. Jorge A. Arroyo
Report completed on March 31, 2011
Energy Optimization of Brackish Groundwater Reverse Osmosis Desalination (final, PDF,
By John MacHarg
Report completed on September 09, 2011