الفهرس 
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Abstract
Although color makes the world beautiful, but it kills the creatures like sweet poison. So in our thesis focused on dye removal by stripes of double layer membrane fiber (DLMF) Using adsorption technique. DLMF prepared by casting (poly vinyl alcohol/carboxy methyl cellulose and oxalic acid as crosslinker) then fabricating fiber from (poly ethylene oxide with poly vinyl alcohol and oxalic acid as crosslinker) on membrane surface. By contact angle, swelling test and tensile strength the optimum conditions for preparation determined which are 1: 8: 0.8 mass ratio for PVA: CMC-Na: OA respectively.
The mixture of PVA/CMC-Na dissolved firstly at 90 C° for 180 minutes then crosslinked by oxalic acid. Different characterization techniques were used for DLMF which are:
- FT-IR: which represents disappearance of main function groups of PVA an CMC due to crosslinked by oxalic acid, also disappearance main functional groups for PEO in fiber after crosslinking.
- XRD: A decrease in in d spacing and peak intensity observed after crosslinking, as the crosslinking promotes the decrystallization of the intermolecular hydrogen bonding among the chains of the cellulose
- SEM: The good porous and homogenous surface of fiber supported on good legend for membrane observed from SEM pictures.
- TGA: Good thermal stability for membrane and fiber specially after crosslinked which indicate the ability of using DLMF in hot or cold water without degradation of DLMF material.
Crystal violet was recording the higher dye removal ratio than Congo red and malachite green, this is due to nature of crystal violet as a cationic dye while PVA, CMC-Na are anionic polymers.
The optimum processing conditions for crystal violet dye removal by DLMF were 20 g/L for DLMF in 100 ppm dye solution agitated at 200 rpm for 30 min at ambient temperature.
By applying different isotherm models on removal process the most suitable isotherm was Freundlish which means that adsorption occurred by heterogeneity of sites as it is physical adsorption.
Kinetic models result indicate that removal process follow second order rate model as removal depends on both DLMF and crystal violet quantities, and the rate determine step for removal is pore diffusion step. As Elovich kinetic model failed in identified process as it is physical adsorption.