الفهرس Only 14 pages are availabe for public view
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Abstract
Desalination is characterized by rapidly evolving technologies. These technologies are divided mainly into thermal and membrane processes. Thermal processes, however, have numerous limitations, which include high energy consumption and corrosion problems while membrane processes mainly suffer from membrane fouling and high membrane cost. Liquid membranes (LMs), on the other hand, which have been discovered in 1968 by Li , have no pores to be blocked and cannot be fouled like solid membranes. However, their main problem is the method of containing the liquid between the two miscible but separated donor phase and acceptor phase. in the present work, desalination using the supported liquid membrane and the flowing liquid membrane techniques have been investigated in the desalination of saline water. For the supported liquid membrane, a simple apparatus devised and constructed in our lab, was used to conduct the experiments. A preliminary investigation in part 1 followed by an extended study in part 2 were conducted. Various factors that would affect the degree of desalination were studied and these were: type and quantity of organic membrane liquid, presence of emulsifier and mobile carrier in the LM, concentration of mobile carrier in LM, presence 01’ complexation agent (sequestrant) in the acceptor phase and presence of air sparging or magnetic stirring. The volume ratio of donor phase to acceptor phase was initially studied but later was kept constant at 4:1. in all the experiments simulated seawater or brackish water of different concentrations were used. Cellophane constituted the support for the LM. The most important findings emphasized the importance of the presence of mobile carrier in the LM to enhanc mass transfer through the LM and that an optimum concentration of mobile carrier existed. Also the importance of stirring in promoting mass transfer by minimiiing the boundary layer adjacent to the cellophane support was clarified. Regarding desalination using the flowing liquid membrane, the saline donor phase and the acceptor phase are made to flow co-currently in up-flow, while being separated by two cellophane sheets are to contain the organic LM. Variables, which would affect the degree of desalination by flowing liquid membrane technique have been investigated. The variables include volume ratio of donor phase to acceptor phase, presence of complexation agent such as sorbitol, glucose or starch etc... in the acceptor phase, its type and quantity,