Role of pressure-retarded osmosis (PRO) in the mega-ton water project. Issue 55 (25th November 2016)

• Record Type: Journal Article
• Authors: Kurihara, Masaru; Sakai, Hideyuki; Tanioka, Akihiko; Tomioka, Hiroki
• Is Part Of: Desalination and water treatment. Volume 57:Issue 55(2016)
• Page Start: 26518
• Page End: 26528
• Publication Date: 2016-11-25
• Subjects: Seawater desalination -- Reverse osmosis (RO) -- Energy saving -- Low environmental impact -- Energy recovery device (ERD) -- Pressure-retarded osmosis (PRO) -- Concentrated brine -- Hollow fiber module -- Treated sewage -- Fouling -- Concentration polarization; Saline water conversion -- Periodicals; Saline water conversion; Water -- Purification; Periodicals; 628.167
• DOI: 10.1080/19443994.2016.1168582
• Languages: English
• ISSNs: 1944-3994

Abstract

Abstract: Reverse osmosis (RO) membranes have been widely applied to seawater desalination and wastewater reclamation, and many large RO plants (>100, 000 m 3 /d) have been constructed since 2000. Energy efficiency is indispensable for large plants, especially for future mega-ton scale seawater reverse osmosis (SWRO) plant (1, 000, 000 m 3 /d). In order to reduce energy demand in RO operation, high-efficient low-pressure RO membrane, energy recovery device (ERD), and pressure-retarded osmosis (PRO) which would recover power from salinity gradient between freshwater and concentrated brine were studied in the "Mega-ton Water System" project. A PRO hollow fiber membrane module was newly developed, and a practical continuous operation has been examined at a prototype plant for one year. The maximum 13.5 W/m 2 of membrane power density using 10-inch module was established at our prototype PRO plant. As the results of the plant cost estimation and the financial impacts on the energy saving operation at the mega-ton scale SWRO plants, not only 20% energy reduction by the high-efficient low-pressure RO membrane and the ERD but also further 10% energy saving was possible by using the PRO system.