Innovative large-diameter RO system for water reclamation and seawater desalination

This study presents the performance of two innovative large-diameter (16-inch) demonstration reverse osmosis systems (known as Super-Flux RO systems) for water reclamation and seawater desalination in Singapore. Each 16-inch membrane element of the Super-Flux demonstration RO systems was fitted with patented flow distributors on both ends of each RO element to achieve even distribution of feed water into each membrane element. Electrical coils were embedded into the pressure vessels to produce electromagnetic field for fouling mitigation. Computational fluid dynamics results had verified that feed water was more evenly distributed at membrane inlet with the new flow distributor, compared to the commonly used anti-telescoping device. The operating data collected from the two demonstration RO systems over a period of 1,200 operating hours showed the excellent performance of the Super-Flux RO system regardless of the type of feed water. Both demonstration RO systems produced high quality permeate water and did not show any signs of membrane fouling, i.e., feed pressure, salt rejection and average permeate flux were consistent in the test periods. The average permeate flux of the Super-Flux demonstration RO system for water reclamation was about 2.6 times the value of the existing conventional 8-inch full-scale RO system.