Thesis (M.S.)--Brigham Young University. Department of Mechanical Engineering, 2004. / Includes bibliographical references (p. 79-81).

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 67-69).

Thesis (M.S.)--University of California, Berkeley, 1963. / "UC-25 Metals, Ceramics, and Materials" -t.p. "TID-4500 (19th Ed.)" -t.p. Includes bibliographical references (p. 70-71).

Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xiv, 131 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 91-94).

Thesis (doctoral)--Friedrich-Wilhelms-Universität Berlin, 1842. / Interleaved with blank pages. Also available on the Internet.

Forward osmosis (FO) is an osmotically driven process that uses a high concentration draw solution to pull water across a semipermeable membrane from a feed solution. Wastewater, seawater, or other contaminated water sources may be used as a feed solution. In FO, the final product is not clean water but a diluted draw solution. However, FO may be combined with another process, e.g. reverse osmosis (RO). The resulting hybrid process offers advantages compared to the RO process in, for example, seawater desalination. Thin-film composite (TFC) membranes have been used in pressurized processes such as RO due to their thick porous support layer and their ability to endure high hydrostatic pressures. However, the presence of a thick porous layer is detrimental for FO processes. It is responsible for the internal concentration polarization (ICP) inside the membrane, reducing the osmotic driving force and the overall water flux. The characterization of membranes in FO applications is key for understanding how different intrinsic parameters affect membrane performance. In this work, a previously developed methodology for characterizing TFC membranes was improved. Experimental data was obtained from a laboratory-scale FO system, and the experimental data was used to determine three intrinsic transport parameters, namely the water permeance, the salt permeance and the porous layer structural parameter. With this method, the characterization of TFC membranes can be achieved based exclusively on FO data. A sensitivity analysis has highlighted the impact of the intrinsic transport parameters on an FO membrane performance.

Cellulose acetate membranes show a higher permeability to water than to salt and are being used for desalination of salt water by reverse osmosis. Use of highly acetylated cellulose membranes give a higher salt rejection but also decrease flow rate of the water. The addition of very-short-chain substances or alkyl groups larger than one carbon atom to the cellulose membrane also decreases water flux. A proposed mechanism of transport through the membrane is that the water molecule is passed along the chain by hydrogen bonding with the acetyl groups, The NMR shows a change in the chemical shift of water with an increasing concentration of an acetylated saccharide or with decreasing temperature which indicates hydrogen bonding. The ring oxygen of Tetrahydropyran is a poor hydrogen bonding site according to NMR data. Also from NMR data, Cellulose Triacetate ties up at least 18 water molecules. The osmometer data indicates that α-D Glucose Penta-acetate has two hydrogen bonding sites per molecule with Phenol.

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