الفهرس 
Chapter One : IntroductionOnly 14 pages are availabe for public view
 |  | from | 122 |  |  |
| | | from | 122 | | |
Abstract
-Providing clean water to the majority of population around the world is the most important challenge facing humanity today. Billions of liters of industrial wastewater are produced every day one of this is The pollution induced by dyestuff losses and discharge during dyeing and finishing processes in the textile industry which has been a serious environmental problem for years, its major problem is strong color wastes that are lost after the dyeing process up to 50 %. The discharge of dyeing wastewater into streams and rivers causes several problems. Therefore, it is necessary to treat dye wastewater before discharged it into water. There are various treatment methods used for the removal of dyes including, physical, physico-chemical and chemical processes, these methods have different color removal capabilities, capital costs and operating rates. Electrocoagulation (EC) is an alternative technology for wastewater treatment, it has been successfully used for decolorization of dye solutions from textile wastewater also, in this thesis it is dedicated to study the effect of addition of electromagnetic field on the rate of removal of dyes by EC.
C.I. Acid Red 14 (AR14) Azo dye removal by electrocoagulation in batch reactor was investigated Several parameters were studied such as time of electrolysis (0-30 min), effect of stirring (25-300 rpm), conductivity (3-10 g/l NaCl), current density (60-250 A/m2), cathode shape (sheet/screen), number of cathode (1,2and 3 screens), initial concentration of dye (50-300 ppm), and different electromagnetic field direction (parallel/perpendicular) using baffled and unbaffled reactor.
It was found that the performance of screen cathode is superior to that of flat cathode for baffled reactor design. Percent color removal (after 18 minutes at 100 rpm) was 77.5 % and 86 % for cylindrical sheet cathode and one cylindrical screen cathode respectively.
Increasing the number of screens per cathode improve the percent of dye removal up to 91 % in the unbaffled reactor in 12 minutes at 100 rpm (Using 3 screens).The enhancement of color removal reached 97 % in comparison with using one screen cathode in the unbaffled reactor.
Mechanism of improving color removal efficiency using screen cathode was given. The dye removal was found to increase by increasing agitation speed, current density and electrolyte concentration. While it decrease by increasing dye concentration.
Electrical energy consumption ranged from 0.5 to 19.89 Kwh/kg of dye removed depending on the operating conditions.
EMF has a positive effect on color removal and energy consumption where color removal was 90.42 % and 92.52 % in presence of parallel and perpendicular field respectively, compared to 81 % in absence of magnetic field. Also, energy consumption was reached 4.23 and 3.5 KWh/kg dye removed for parallel and perpendicular direction instead of 6.31 KWh/kg dye removed without magnetic field at 12 min using baffled reactor.