OCEANSIDE, CA, July 14, 2008 -- The Affordable Desalination Collaboration (ADC) has completed a significant comparative test profiling state-of-the-art performance for spiral wound reverse osmosis (SWRO) technology. Ran over two years, the testing compared six sets of standard 8" diameter membranes in seven-element pressure vessels; elements were provided by membrane industry leader Hydranautics (SWC5) and three other membrane element manufacturers.
ADC -- of which Nitto Denko-Hydranautics is a member -- has a mission to "demonstrate affordable, reliable and environmentally responsible reverse osmosis desalination technologies and to provide a platform by which cutting edge technologies can be tested and measured for their ability to reduce the overall cost of the SWRO treatment process." The current ADC testing, conducted at the U.S. Navy's Seawater Desalination Test Facility in Port Hueneme, achieved two milestones: the development of a data set benchmarking SWRO performance for Southern California applications, and demonstration of SWRO's affordability in comparison with traditional sources of potable water.
During the 9-week test phase, Hydranautics SWC5 provided superior salt rejection while requiring lower than average net driving pressure. At optimized operating conditions and with use of an energy recovery device, SWC5 can produce potable-quality permeate at an energy consumption of 1.7 kwhr/m³ or greater. By achieving such high quality permeate; the SWC5 produces the required product water - frequently with single-pass RO system design. Remarkably, the SWC5 achieves such high permeability/low energy operation while still offering 99.8% nominal salt rejection and 92% nominal boron rejection. This advancement has been achieved through refinements of the proven SWC membrane chemistry, maximization of surface area through the use of manufacturing automation, and the selection of high performance element components.
The tables below normalize the MAP (Most Affordable Point) conditions while illustrating the ADC's findings. The MAP conditions were normalized using ASTM standard calculations. (Key system variables of recovery and flux ranged from 43-50% and 6-10 gallons per day per square foot of membrane (gfd). Note: higher water transport coefficient is preferred; lower salt transport coefficient is preferred.)
Hydranautics and parent company Nitto Denko together form an industry leader for membrane development with a focus on unique surface coatings.
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