الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
Chlorination is the most widely used process (ur drinking water disinfection. The technique has been developed and .pra~ticed for at least 75 years. Recent discoveries, shed some doubts on the safety of this practice. Chlorine, the prime disinfectant of drinking water in Egypt, has been found to react with organic matter naturally present in the surface waters, to form the cancer causing trihalomethane compounds. This problem, besides the need to abat e environmental hazards, are currentI y challenging scientists and engineers to develop alternat~ve disinfectants for drinking water. Ozone as disinfectant, is considered as the best alternative for chlorine. Water ozonation must be backed up by chlorination to assure a disinfectant residual in distribution systems. it is recommended that the combination of both techniques (chlorination - ozonation), ! will su~stantially improve the drinking water quality and safety. I So I far, ozone has been produced in practice by electric discharge which is energy intensive. This means a need fO* chlorine and ozone generators using alternative . techniquy, to provide adequate supply of disinfectants at reasonable costs and appropriate technology, as the spark method suffers from the high capital and operating costs. The present work aimed to design, develop and put ,’ into operation simple, low voltage, and compact units for chlor~ne and ozone generat~on tor insitu drinking water disinfection. Electrochemical method is still early stage of development for ozone generation. Although chlorine productlon by electrolYS1S ~s an old technology, there was a chance for developing insitu chlorine generator which differ in design and operating conditions from the conventional cell.::; , Lu .::;U.l.L tt1t: eXl.::;L.l.ny cond.l.Llons .l.n cl develop.l.ng country. Another objective of this work, was to study the factors affecting the cell vol tage, and explore the possibility of improving voltage efficiency by early removal of gas bubble accumulation on the electrode surface and in the anode gap. A cell was designed using plexyg1ass, to be consisted of two r~ctangular compartments, with a dimensions of 15 x 16 x 6 cm. The cell was divided by a porous P.V.C. diaphragm to prevent the ozone or chlorine generated at the anode from being reduced at the cathode, and to avoid I mixing of hydrogen ion generated at the cathode with ozone or chlorine generated at lhe anode. The cell cathode was made of nickel plated copper screen. The cathode gap was made zero to minimize the internal cell resistance. The cell anode was made of lead dioxide supported on a rectangular graphite plate in case of ozone generation, wt1ile in case of chlorine generation, the anode was made of rectaqgular graphite plate. Electrical circuit was consisted of the cell, a multirange ammeter and 10 volt are power supply with voltage regulator connected inseries. A voltemeter was connected in parallel with the cell to measure the actual \ cell vol1;:age. A storage tank and centrifugal pump (t hp) were added to the above mentioned apparatus assembly when the cell was operated under forced convection. The electrolysis was conducted for both ozone and chlorine generation at 10 current density values, / different gap widths and j values oL clearance height. In case of forced convection (mechanical circulation of solution), b different flowr~tes were used wIth constant gap width ( 2 cm) . The electrolysis of sodium chloride solution in case of chloriQe generation, was repeated for ’Ic two.different concentrations (28 and 3 ). I . Current-voltage dat,.a were measured, and the current efficlency of ozone and chlorine generation WGB cQlculated from the experimental results at different current den.sitieA. The results were presented in tables and fIgures to show the actual cell voltage, voltage efficiency, power ’. consumption and energy. etticienc,.. The optimam conditions tor both ozone and chlorine generation , were concluded trom the results as tollows: tor ozone generation; optimum current density, gap width and cell voltge are 80 mA/cm2.’2 Cm . . and 5. 82 volt respec’ively.