About: Forward osmosis is a(n) research topic. Over the lifetime, 4372 publication(s) have been published within this topic receiving 127760 citation(s). The topic is also known as: FO.
15 Sep 2006-Journal of Membrane Science
Abstract: Osmosis is a physical phenomenon that has been extensively studied by scientists in various disciplines of science and engineering. Early researchers studied the mechanism of osmosis through natural materials, and from the 1960s, special attention has been given to osmosis through synthetic materials. Following the progress in membrane science in the last few decades, especially for reverse osmosis applications, the interests in engineered applications of osmosis has been spurred. Osmosis, or as it is currently referred to as forward osmosis, has new applications in separation processes for wastewater treatment, food processing, and seawater/brackish water desalination. Other unique areas of forward osmosis research include pressure-retarded osmosis for generation of electricity from saline and fresh water and implantable osmotic pumps for controlled drug release. This paper provides the state-of-the-art of the physical principles and applications of forward osmosis as well as their strengths and limitations.
01 Jan 2019-
Abstract: Rapid population growth increases the demand for freshwater. Membrane technology is playing a dynamic role in the production of clean water from seawater and wastewater. The desalination of seawater using forward osmosis (FO) is an emerging technology to produce freshwater, as it is energy efficient than the conventional processes. In recent days, a significant amount of work has been carried out to produce high-performance FO membrane for desalination. In this chapter, usage of different types of membranes for FO desalination application and their performances enhancement by suitable modification has been discussed.
01 Nov 2006-Journal of Membrane Science
Abstract: Osmosis through asymmetric membranes has been studied as a means of desalination via forward osmosis and power generation through a process known as pressure retarded osmosis. The primary obstacle to using asymmetric membranes for osmotic processes is the presence of internal concentration polarization, which significantly reduces the available osmotic driving force. This study explores the impact of both concentrative and dilutive internal concentration polarization on permeate water flux through a commercially available forward osmosis membrane. The coupling of internal and external concentration polarization is also investigated. A flux model that accounts for the presence of both internal and external concentration polarization for the two possible membrane orientations involving the feed and draw solutions is presented. The model is verified by data obtained from laboratory-scale experiments under well controlled conditions in both membrane orientations. Furthermore, the model is used to predict flux performance after hypothetical improvements to the membrane or changes in system conditions.
01 Apr 2005-Desalination
Abstract: A novel forward (direct) osmosis (FO) desalination process is presented. The process uses an ammonium bicarbonate draw solution to extract water from a saline feed water across a semi-permeable polymeric membrane. Very large osmotic pressures generated by the highly soluble ammonium bicarbonate draw solution yield high water fluxes and can result in very high feed water recoveries. Upon moderate heating, ammonium bicarbonate decomposes into ammonia and carbon dioxide gases that can be separated and recycled as draw solutes, leaving the fresh product water. Experiments with a laboratory-scale FO unit utilizing a flat sheet cellulose tri-acetate membrane demonstrated high product water flux and relatively high salt rejection. The results further revealed that reverse osmosis (RO) membranes are not suitable for the FO process because of relatively low product water fluxes attributed to severe internal concentration polarization in the porous support and fabric layers of the RO membrane.
21 Apr 2010-Environmental Science & Technology
TL;DR: The development of a high performance thin-film composite membrane for forward osmosis applications with high water flux was directly related to the thickness, porosity, tortuosity, and pore structure of the polysulfone support layer.
Abstract: Recent studies show that osmotically driven membrane processes may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation onto a thin (40 μm) polyester nonwoven fabric. By careful selection of the polysulfone casting solution (i.e., polymer concentration and solvent composition) and tailoring the casting process, we produced a support layer with a mix of finger-like and sponge-like morphologies that give significantly enhanced membrane performance. The structure and performance of the new thin-film composite forward osmosis membrane are compared wi...