William L. Thayer

Specification of commercial reverse osmosis modules and predictability of their performance for water treatment applications

Abstract Techniques for specifying membranes in commercial modules and reverse osmosis systems involving such modules, and for predicting data on performance of the modules so specified are illustrated with particular reference to water treatment applications. Four commercial modules (Roga-4000, Westinghouse, Raypak and Du Pont-B9) were studied in. this work for such specification and prediction. Experimental reverse osmosis data using NaCl-H2O feed solutions were used for obtaining data on membrane specifications. Equations of system analysis were used for prediction of data on module performance. Three sets of calculated data are reported for the operating pressure of 2758 kPa gauge (400 psig). The first set of data shows good agreement between calculated and experimental results on the performance of the modules with aqueous sucrose feed solutions. The second set of data shows the variations in solute separation and membrane productivity for each of the four- modules studied as functions of volumetric fraction product water recovery and membrane compaction for a 3000 ppm NaCl-H2O feed solution. The third set of data shows the variations in solute separation as a function of solute transport parameter at different levels of mass transfer coefficient on the high pressure side of the membrane for very dilute aqueous feed solutions.

High flux cellulose acetate ultrafiltration membranes

Abstract Conditions for casting high flux tubular and flat cellulose acetate ultra-filtration membranes are given. The usefulness of some of the tubular membranes cast under the above conditions for ultrafiltration applications in industrial water purification and reuse is illustrated. Using ethanol-water mixture as the gelation medium in the temperature range-20° to 30°C, ultrafiltration membranes giving water fluxes in the range 400 m3/m2 day at the operating pressure of 689.5 × 103 Pa (100 psig) have been obtained.

Treatment of crude petroleum/water emulsions by agglomeration methods using fine coal

Persistent crude petroleum-water emulsions are produced in the recovery and extraction of heavier oils, for example, in the hot water processing of surface mined oil sands and during in-situ methods such as steam- or water-flooding. Over the past few years, much attention has been directed to the oil agglomeration method as a means of recovering and upgrading fine coal in water suspensions. The work reported here concerns the use of crude petroleum from produced emulsions in the coal agglomeration process. Two problems are adddressed in this way. Not only is oil recovered and emulsions broken in the case of the produced emulsions, but the coal is also benificiated through the rejection of water and inorganic impurities because of the selectivity of the agglomeration technique. Laboratory-scale experiments are reported using three different samples of produced emulsion from western Canada and a fine coal from waste tailings of a coal preparation plant. Results of the experiments are considered from the poi...