الفهرس 
Chapter One : IntroductionOnly 14 pages are availabe for public view
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Abstract
Release of dyes into the environment from industrial practices is a matter of global concern.Dyes are emitted from industrial plants in the form of aqueous effluents. They are widely used in several industries like textile, dyeing, paper and pulp, tannery, paint industries etc. Dyes are considered an objectionable type of pollutant because they are toxic in nature. Their classification can be done based on their usage, group and solubility. The textile industry is one of the largest polluters in the world. However, the majorproblem is strong color wastes that are lost after the dyeing process up to 50%. The discharge ofdyeing wastewater into streams and rivers causes several problems. Therefore, it is necessary totreat dye wastewater before discharged into water.
Various treatment processes used for the removal of dyes include adsorption, microbial degradation, oxidation, etc. Electrocoagulation (EC) has been successfully used for decolorization of dye solutions from textile wastewater and thesis is dedicated to studying 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 under effect of electromagnetic field (EMF), and without electromagnetic field. Several parameters were studied such as current density(37-92A/m2), time of electrolysis(1-10min), effect of stirring (275-750 rpm), anode shape (plates/cylindrical), conductivity (2-12g/l NaCl), initial pH (4-10), type of anode material (Al/Fe), temperature (299-373 k), initial concentration of dye(30-250ppm), and different electromagnetic field direction and intensity (EMFI). It was found that the efficiency of color removal increases with increase current density, conductivity, and with increase of rotational speed, while it decreases with increase initial dye concentration and with increase temperature. The optimum pH was found at pH 6 on using iron anode and pH 3 when Al anode was used. Rotating cylindrical anode gives better results than plate anode at the same operating conditions. The electrocoagulation stage was optimized in order to design an economically feasible process. The maximum color removed using iron anode was 94.14 % at current density 75 A/m2, electrolysis time of 6 min, initial pH = 6, CNaCl = 10 g/l, and 275 rpm for 250 ppm dye. On using aluminum anode, the maximum color removed was 94.39 % at current density 66 A/m2, electrolysis time of 30 min, initial pH = 3, CNaCl = 2 g/l, and 275 rpm for 250 ppm dye. Under influence of electromagnetic field the removal percent of dye is 98.23 % after 4 minutes using iron anode and the removal percent of dye is 96.76 % after 10 minutes for using Al anode. These results showed that the application of EMF strongly enhances the rate of removal process. This work demonstrates that the enhancement of dye removal in presence of EMF is due to the induced motion of ions in the solution when EMF was used in a direction perpendicular to EC reactor.