Reverse-osmosis membrane separation characteristics of various organics: prediction of separation by surface force - pore flow model and solute surface concentration by finite-element method
An aromatic polyamide membrane was used to study the separation of selected carboxylic acids, chlorophenols, nitrophenols and sodium chloride. An application for actual treatment of a coal-liquefaction waste water was also performed. Prediction of separation and flux data were obtained using the surface force pore flow (SFPF) model previously reported in the literature. Methods for the determination of pore size distribution of polyamide thin-film composite membrane and a cellulose acetate ultrafiltration membrane, solute concentration at the membrane wall are described. The pore distribution data and wall concentration data were further used with solute separation data at a particular pressure to obtain the solute-solvent-membrane wall forces parameter involved. From the knowledge of the interaction forces, the solute separation and flux data (for nonionized organic solutes and sodium chloride) were predicted over a wide range of pressures and showed excellent agreement with experimental data. The prediction of rejection and flux for carboxylic acids, chlorophenol and nitrophenol systems by the SFPF model were further extended to multicomponent systems. The polyamide membrane used in this study had 97-99% standard NaCl rejections and 24-30 gfd pure water flux at 20.7 x 10/sup 5/ N/m/sup 2/. For ionizable organics such as phenol, chlorophenol, dichlorophenol..., the rejection and flux drops were highly dependent on operating pH values. Membranes experimental results showed 99.5-99.8% rejection at pH 11 of phenol, 2-CP and 2,4-DCP. Under no ionization conditions the flux drop observed for nitrophenol and chlorophenol systems was not caused by osmotic pressure effect and was related to physicochemical nature of the solute-solvent-membrane system.
- Research Organization:
- Kentucky Univ., Lexington (USA)
- OSTI ID:
- 6849612
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBOXYLIC ACIDS
SEPARATION PROCESSES
COAL LIQUEFACTION
WASTE WATER
NITROPHENOL
ORGANIC CHLORINE COMPOUNDS
PHENOLS
SODIUM CHLORIDES
PROCESSING
MATHEMATICAL MODELS
MEMBRANES
OSMOSIS
POLYAMIDES
ALKALI METAL COMPOUNDS
AROMATICS
CHLORIDES
CHLORINE COMPOUNDS
DIFFUSION
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LIQUEFACTION
LIQUID WASTES
NITRO COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
OXYGEN COMPOUNDS
POLYMERS
SODIUM COMPOUNDS
THERMOCHEMICAL PROCESSES
WASTES
WATER
010405* - Coal
Lignite
& Peat- Hydrogenation & Liquefaction
010800 - Coal
Lignite
& Peat- Waste Management
400105 - Separation Procedures