Dow desalination membrane gives better 2nd-pass rejection

A low-energy reverse osmosis (RO) desalination membrane launched on 17 November 2010 is claimed to achieve better rejection from second-pass systems and reduce operating costs.

The Dow FilmTec™ HRLE-440i is a high-rejection low-energy element that uses advances in membrane chemistry to deliver 99.5% sodium chloride rejection at 150 psi (10.34 bar). Its developer, Dow Water & Process Solutions, says the element delivers effective rejection of silica, boron, nitrate and ammonium with performance supported by the company’s modeling software. The element meets ANSI/NSF 61 certification requirements for drinking-water system components.

“This advance in membrane chemistry allows new RO equipment to be designed around lower pressure membranes, meeting permeate quality with up to 30% less energy than conventional brackish water membranes,” said Chris Sacksteder, strategic market manager for industrial water, Dow Water & Process Solutions. “In addition to energy efficiency, with 440 ft² (40.9 m²) of active area, the HRLE-440i membrane allows fewer elements to be used in a system design. This shrinks the overall system footprint, related energy use and operational costs.”