الفهرس 
Chapter One: IntroductionOnly 14 pages are availabe for public view
 |  | from | 153 |  |  |
| | | from | 153 | | |
Abstract
Water contamination is primary caused by industrial waste, which contains variety of dyes and other contaminants. Numerous industries, including those that manufacture dyes, paper and pulp, textile, food, pharmaceutical and many others, release colored effluent. Two techniques were carried out, in this study, to treat colored effluents: namely adsorption and electrochemical processes.
Bagasse pith, an agricultural waste produced from pulp industry, was successfully converted into a novel magnetic adsorbent via a simple method using iron salt. Bagasse pith and magnetic bagasse pith were characterized through analytical methods: scanning electron microscopy (SEM), XRD and FTIR while, the adsorption characteristics was examined using Methylene Blue. The equilibrium isotherms for the two types of pith were studied at different temperatures, 25: 75ºC and particle size (500-365µm: 180-100 µm); where Langmuir, Freundlich, Temin, and Dubinin- Radushkevich models were used to investigate the equilibrium data, to judge which one simulates the process and determines the adsorption capacity. The results showed that the Langmuir model provide a good description of adsorption behavior. As well as The adsorption capacity was slightly improved due to magnetization of pith which increased from 135.671 mg/g to 146.231 mg/g at 25 ºC and particle size (180-100 µm). In particular, the adsorption rate was so fast that the equilibrium was achieved within 100 min for magnetic pith compared with 140 min for the unmodified one. The external mass-transfer and intraparticle diffusion have been studied with three design variables namely agitation speed, initial concentrations, and mass of adsorbents. Kinetics model Pseudo-first-order and pseudo-second-order were used to analysis the experimental data, and the kinetic data followed the pseudo-second-order model.
A new electrocoagulation (EC) technique was also used, the EC cell consists of iron screen anode and two iron cathodes, inner rod and outer cylindrical sheet. The effect of current density, electrolyte concentration and the initial concentration of pollutant on process performance and energy consumption were investigated for a definite process time. The results showed that process efficiency has a direct proportional with applied current density and electrolyte concentration in contrast with the initial dye concentration. Furthermore, for 293 mg/L initial dye concentration and 16 g/L NaCl, and 2.67 A / m2 removal efficiency reached 93% during 15 min process time when time increased to 25 min 99.5% removal was achieved when all parameters remain constant.