الفهرس 
CHAPTER (1) INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The origin and continuation of mankind is based on water. Water is one of the most abundant resources on earth, covering three-fourths of the planet’s surface. The only nearly inexhaustible sources of water are the oceans, which, however, are of high salinity. It would be feasible to address the water-shortage problem with seawater desalination. The Reverse Osmosis (RO) Membrane Separation Process is a general and widely applicable technique for the separation, concentration or fractionation of substances in fluid solutions. Its most significant application is in the field of saline water conversion. In spite of the rapid advances, which are being made with respect to this application, the process is still at its very early stages of development. The fundamentals of reverse osmosis desalination are explained. The configurations and theory of operation of reverse osmosis systems are presented and discussed. Description of the individual components of reverse osmosis systems and the methods used for energy recovery are also presented. The RO desalination process has been extensively investigated both theoretically and experimentally. A general mass, material and energy balance have been applied to each part of a desalination system leading to a theoretical model. The model is valid for all arrangements of two-module RO desalination system. The model has been solved analytically and a versatile computer program has been coded to perform the different simulation tasks. The model has been extended to study three and four module system with satisfactory accuracy. Effects of feed specifications, operating conditions and membrane dimensions on the system performance and its cost are investigated. Also effects of feed specification operating condition and membrane dimensions on the salt concentration on membrane wall in each module for various arrangements of two modules are investigated. An experimental test set-up has been designed, fabricated and assembled; in order to carry out the required experimental runs. Many experiments have been carried out to investigate the unit behavior under different operating conditions. Also the experimental investigation aims to provide validation of the theoretical analysis for the RO system.
This thesis developed also, a method to simultaneously optimize the module surface area, system structure and operating conditions. The method valid to apply on the single module, the various arrangements of two-module and various arrangements of three-module. The results of the investigation have shown that; increasing the feed pressure improves the performance of the unit and increases the cost. The surface area is strongly affects the performance of RO system. The concentration at the membrane increases with the increase in pressure or concentration of the feed flow. Alternatively, the wall concentration decreases as the feed stream flow rate and temperature are increased. In optimization part for a low demand in fresh water (up to 5 m3/hr), the single module gives a low permeate unit cost compared with two or three module system arrangements. Permeate Re-processing arrangements leads to a waste of some permeate from module 1. They are only appreciated when extremely pure product is desired such as in medical and chemical applications or in case of the old membrane (the rejection factor of membrane is very low and the permeate concentration is high).