A pilot system was designed and constructed to evaluate reverse osmosis (RO) energy reduction that can be achieved using pressure-retarded osmosis (PRO). The RO-PRO experimental system is the first known system to utilize energy from a volume of water transferred from atmospheric pressure to elevated pressure across a semipermeable membrane to prepressurize RO feedwater. In other words, the system demonstrated that pressure could be exchanged between PRO and RO subsystems.
View Article and Find Full Text PDFThe purpose of this study was to determine the comparative environmental impacts of coupled seawater desalination and water reclamation using a novel hybrid system that consist of an osmotically driven membrane process and established membrane desalination technologies. A comparative life cycle assessment methodology was used to differentiate between a novel hybrid process consisting of forward osmosis (FO) operated in osmotic dilution (ODN) mode and seawater reverse osmosis (SWRO), and two other processes: a stand alone conventional SWRO desalination system, and a combined SWRO and dual barrier impaired water purification system consisting of nanofiltration followed by reverse osmosis. Each process was evaluated using ten baseline impact categories.
View Article and Find Full Text PDFEnviron Sci Technol
December 2011
Osmotically driven membrane processes (ODMP) are emerging water treatment and energy conversion technologies. In this work, we investigated the simultaneous forward and reverse (i.e.
View Article and Find Full Text PDFForward osmosis (FO) is a membrane separation technology that has been studied in recent years for application in water treatment and desalination. It can best be utilized as an advanced pretreatment for desalination processes such as reverse osmosis (RO) and nanofiltration (NF) to protect the membranes from scaling and fouling. In the current study the rejection of trace organic compounds (TOrCs) such as pharmaceuticals, personal care products, plasticizers, and flame-retardants by FO and a hybrid FO-RO system was investigated at both the bench- and pilot-scales.
View Article and Find Full Text PDFEnviron Sci Technol
September 2009
Forward osmosis (FO) is an emerging water treatment technology with potential applications in desalination and wastewater reclamation. In FO, water is extracted from a feed solution using the high osmotic pressure of a hypertonic solution that flows on the opposite side of a semipermeable membrane; however, solutes diffuse simultaneously through the membrane in both directions and may jeopardize the process. In this study, we have comprehensively explored the effects of different operating conditions on the forward diffusion of solutes commonly found in brackish water and seawater, and reverse diffusion of common draw solution solutes.
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