Assessment of Low-pressure Membrane Technology to Reduce the Cost of Desalination
Project ID: 4141
Principal Investigator: Katherine Guerra
Research Topic: Desalination and Water Treatment
Priority Area Assignments: 2012 (Advanced Water Treatment)
Funded Fiscal Years: 2011 and 2012
The research questions to be addressed in this project are:
What material properties affect membrane solute rejection and water productivity?
What feed water characteristics are important to consider when selecting a membrane product?
What are the operating conditions that affect membrane solute rejection and treated water productivity?
What are the conditions under which ceramic membranes are more economically favorable than polymeric membranes?
How is the flux of ceramic membranes affected by water quality parameters, operating conditions, and cleaning conditions?
How do changes in operational and water quality parameters affect the overall cost of operation for a low-pressure membrane system?
Need and Benefit
Water treatment applications using low- pressure membranes for bacterium, virus, organic, and particulate removal can be used in place of expensive, labor-intensive, conventional treatment processes. The use of low-pressure membranes in place of conventional treatment and as a pretreatment for desalination is becoming increasing popular.
Improved water treatment technologies, such as low pressure membranes, help to increase the water supply to areas of the West where demands will soon exceed supplies. Effective use of low-pressure membranes can also significantly decrease the cost of desalination and traditional water treatment and substantially reduce the energy demand for water production. The need for more research on microfiltration (MF) and ultrafiltration (UF) membrane systems is stated in the "Desalination: A National Perspective" report by the National Research Council on Desalination: "MF and UF pretreatment systems are likely to gain popularity due to the superior quality of water produced," and "to realize the benefits of high flux reverse osmosis membranes, more effective pretreatment systems will be needed."
Membrane material properties, the physical pore size of the membranes, the characteristics of the feed waters to be treated, and the operational conditions of the membrane process affect the rejection and rate of production of product water for the membrane process. Little guidance exists in the industry to help membrane users select the most efficient low-pressure membrane pore size, material, and process operating conditions; therefore, this research could help to fill that gap in knowledge.
Also, low-pressure membranes are manufactured by many different companies and are often sold as package plans to end users. Additionally, there are no standard sizes and configurations for low-pressure membranes. Therefore, each manufacturer has adapted their technology to meet customer needs. Membrane manufacturers are commonly not willing to invest in this type of research because the end result, or optimal solution, may be a product configuration, material, or mode of operation that is different from the product they sell.
Furthermore, one of the main benefits of this work is that it will help identify areas where future research efforts should be focused.
Independent Peer Review
The following documents were reviewed by qualified Bureau of Reclamation employees. The findings were determined to be achieved using valid means.
Techno-economic model for evaluation of ceramic membranes for surface water treatment (interim, PDF,
By Katherine Guerra
Report completed on June 27, 2012
Investigation of low pressure membrane performance, cleaning, and economics using a techno-economic model (interim, PDF,
By John Pellegrino
Report completed on October 17, 2012
This information was last updated on April 16, 2014
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