Novel 16-inch spiral-wound RO systems for water reclamation - a quantum leap in water reclamation technology

Abstract

Two 16-inch pilot RO systems (designated as 2EPV and Super-Flux) that incorporated 16-inch RO membrane elements, innovative patented flow distributors for even distribution of feed water into and out of each RO membrane element and electromagnetic field (EMF) coils in the pressure vessels for fouling mitigation were tested at a local water reclamation plant. Their performance was compared with the existing full-scale conventional 8-inch RO system. All RO systems used ultra-filtrated secondary effluent from a nearby wastewater treatment plant as the feedwater. The average permeate fluxes of the 16-inch 2EPV (2 elements per vessel) and Super-Flux (4 elements per vessel) RO systems were found to be about 2 and 2.6 times, respectively, higher than that of the full-scale 8-inch RO system. The feed pressure and salt rejection of both 16-inch pilot RO systems were better maintained than the full-scale 8-inch RO system, suggesting that both 16-inch pilot RO systems were more capable of inhibiting membrane fouling. The effectiveness of EMF in reducing RO membrane fouling in the 16-inch pilot RO system had also been demonstrated in this study. The energy consumed by the 16-inch pilot RO system was about 12-16% lesser than that of the 8-inch full-scale RO system. Projections based on the average operating permeate fluxes obtained showed significant savings in the number of RO elements and pressure vessels when the 16-inch Super-Flux RO system is adopted instead of the 8-inch RO system. © 2008 Elsevier B.V. All rights reserved.