How Does HEEPM™ Work?

The patented High Efficiency Electro-Pressure Membrane (HEEPM™) process may use traditional electrodialysis or High Efficiency Electrodialysis (HEED®) technology in conjunction with nanofiltration or reverse osmosis membrane elements, to produce a high purity product stream and highly concentrated brine stream. Overall performance of HEEPM™ is optimized and capital and operating costs minimized when HEED® is integrated with HEEPM™, as it offers the most effective and efficient electrodialysis currently available.

Electrodialysis is an electro-membrane process in which the ions (ionized and ionizable species) are transported through a membrane from one compartment to another under the influence of an electrical potential. In effect, ions are driven from a region of low concentration to one of high concentration (to help visualize the process, please view our HEED® video at

Nanofiltration and reverse osmosis are processes in which a water (or other solvent) stream is passed through a semi-permeable membrane that rejects the ions. In the nanofiltration and reverse osmosis pressure driven processes, the selected semi-permeable membrane determines the degree of separation of one component of a solution from another based on the component's properties (e.g., charge), as a result of size exclusion, and as a result of the process operating parameters (e.g., pressure, flow rate). Nanofiltration/reverse osmosis and electrodialysis do not have much in common with the exception that in both processes semi-permeable membranes are used as key elements in performing the separation, resulting in significant energy savings compared to thermal processes such as distillation or evaporation, and substantial operational cost savings compared to ion exchange resin bead methods.

In general, electrodialysis processes operate most efficiently with higher concentration, more conductive solutions, while nanofiltration/reverse osmosis processes perform better (higher solute rejection, higher flux) with lower concentration solutions.

The patented High Efficiency Electro-Pressure Membrane (HEEPM™) process takes advantage of the respective differences and advantages of electrodialysis and nanofiltration or reverse osmosis by combining both processes in a manner optimizing the separation characteristics of each. Use of the integrated HEEPM™ approach overcomes inherent limitations of both membrane-based technologies, allowing these to operate optimally and economically, thereby achieving improved efficiencies, product recovery, and finished product quality.


For more HEEPM™ information, click here

For a general discussion of electrodialysis and reverse osmosis, click

More ED and RO background.

For additional information about HEED® see

For additional information about nanofiltration and reverse osmosis, see

pdf A Review of Wastewater Treatment by Reverse Osmosis

 A Brief Review of Reverse Osmosis Membrane Technology

         A Review of Reverse Osmosis Theory

What is HEEPM™

What Benefits Does HEEPM™ Offer?

How Does HEEPM™ Work? (In-depth)

HEEPM™ Applications
HEEPM™ Specifications

HEEPM™ Key Features

Contact EET for more information.

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