Membrane System Design Assistant

Membrane filtration systems are used to purify water and treat waste. These types of liquid filtration systems help meet water quality requirements for municipal and industrial applications. There are four categories defined by the size of the material that can be removed from the liquid.  From largest to smallest pore size, they are:

• Microfiltration
• Ultrafiltration
• Nanofiltration
• Reverse osmosis

EPA’s Total Flux and Scaling spreadsheet is a membrane design assistant that uses Microsoft Excel to help users evaluate reverse osmosis and nanofiltration filtration systems, and then design a membrane system using generic membrane elements or custom-made elements specific to a particular need.

The spreadsheet enables users to:

• Determine solubility conditions for the feed and concentrate streams using a variety of methods
• Determine charge balance
• Calculate a carbonate equilibrium based on pH and temperature
• Specify the use of acid or a softening resin to pre-treat the water
• Store analyses and project information within the spreadsheet itself

The Total Flux and Scaling spreadsheet also has the capability to export scaling calculations to other systems.

In addition, users can calculate pressure and pressure drops, and the ion-by-ion salt passage through membranes. The ionic concentration of each stream can then be determined, as well as the scaling index for many scaling species using American Society for Testing and Materials International (ASTM) methods or methods based on ion complex calculations closely resembling the traditional programs used in the geological sciences.

Technical Contact:

Tom Speth (513) 569-7208

See Also:

Total Flux and Scalant Program Final Report (PDF, 94 pp, 332 Kb)

The Total Flux and Scaling spreadsheet (Zip File, 583 Kb)

ASTM