الفهرس 
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Abstract
Phenols are coming from industry due to with the quick development of the world, there are extremely many factories use a massive quantity of water in their different processes and as a result generate many wastewaters which contain phenol.
Phenols have classified as the top 45th priority hazardous pollutants materials, which need urgent treatment before entering into the environment. Phenolic compounds are carcinogenic and quite stable as they remain in the environment for longer period and can exert harmful effects on different biological processes.
Phenols are certainly the most difficult to remove and they are resistant to natural biodegradation, because of complexity of the aromatic structure of phenol. So, removing these organics or decreasing their concentrations to the permitted levels before discharging becomes a challenging issue.
To save the soils and aqueous ecosystems, it has been a serious need for industries to treat their wastewater effluents that containing phenolic compounds before discharge disposal to the environment. The most frequently method and widely used for the phenolic pollutions removal is physical adsorption method. It is usually considered to be the best and relatively economical method. As, it has many advantages such as low operating cost, simple, effective, feasible, versatile, and it does not require high amounts of energy. Therefore, the search for low cost and easily available adsorbents. As a result, the present thesis is aiming to improve the performance of cellulose acetate nanofibers (CA nanofibers) that used as an adsorbent for removal of phenol from wastewater, by using nano magnetite zinc oxide (ZnO). The nano magnetite zinc oxide (ZnO) cellulose acetate nanofibers composites prepared by electrospinning technique. These are composed of three components, and therefore can exhibit the properties of multicomponent systems in the same material.
we have focused on the nanofiber materials in adsorption, as recycling of powdered nanoparticle materials has been difficult. Nanofiber technology has gained a wider application due to its large surface area to volume ratio that gives them high functionalization ability, excellent mechanical behavior, durable, easily moldable, chemical resistant, high porosity and small pore size, in addition to inherent low cost, more effective, simplicity and versatility. In addition to Cellulose acetate nanofiber has good biocompatibility and biodegradability, good thermal stability, cost effectiveness, relatively easy manufacture, renewable resource of raw material, non-toxicity and chemical resistance, CA fibers present better physical properties, a higher modulus, adequate flexural and tensile strength. There are some restrictions of CA that makes itself become limited to use for adsorption such as not suitable for more aggressive cleaning, has low oxidation and chemical resistances, and poor mechanical strength. Thus, the modification of CA gains importance.
Therefore, CA is often used to combine with other materials to enhance their mechanical strength and adsorption efficiency by immobilization of inorganic materials like nano-magnetite ZnO on CA nanofiber.
As, nano-magnetite ZnO has high surface area, porosity, chemical stability, low cost, environmentally friendly, higher absorption capacity, nontoxicity, an efficient photocatalytic removal efficiency through adsorption and decomposition of organic contaminants, economical and possess a promising adsorption capacity for contaminants along with optimal magnetic properties, showing rapid separation of the adsorbent from solution by an exter¬nal magnetic field.
The most proper cellulose acetate nano-fiber that was electro-spinned using 10 % CA solution dissolved at 2:1 acetone to dimethylacetamide (DMAc) which is spinned at 13 KV and 25 cm electro-distance with rate 0.5 ml/h. This CA nano-fiber characterized by its homogeneous and thin nano-fiber with average diameter 100 nm. This optimized CA nano-fiber was immobilized with various weight fractions from magnetic zinc oxide nano-powder to fabricate novel magnetite zinc oxide cellulose acetate hybrid nano-fiber using electro-spinning technique. The three different fabricated magnetic hybrid nanofibers were monitored against phenol decontamination from synthetic polluted wastewater using batch technique. The fabricated magnetic hybrid nanofiber that was immobilized with 0.1 %vol. magnetic zinc oxide recorded the highest phenol percentage removal of 64 % within 2 hours.
The structural and morphological properties of the samples were studied by X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The presence of functional groups and chemical bonding are confirmed by Fourier transform infrared (FT-IR). And study the factors which effect on phenol removal (%) such as initial phenol concentration, adsorbent dose, pH, temperature and contact time. The maximum removal efficiency was 99 % under 5 ppm of initial phenol concentration, 1 gm of adsorbent dose, natural pH value of 8 and 120 min of contact time at room temperature 25 oC. Moreover, the prepared adsorbent could be easily recycled from an aqueous solution by an external magnet and reused for adsorption with high removal efficiency.