الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Over the last decades, contamination of water by organic pollutants like phenolic compounds and dyes has steadily been increased as a result of over population and expansion of industrial activities. Due to the organic pollutants toxicity and their serious threat to human health and ecological systems, intensive research efforts are continuing to create less costly treatment technologies appropriate a variety of industrial simulations. Currently, adsorption is believed to be a simple and effective technique for water and wastewater treatment where the success of the technique largely depends on the development of an efficient adsorbent.
In this study, three different kinds of adsorbents were prepared and synthesized by using different methods like oxidative polymerization to synthesize Polyaniline (PANI) and Polyaniline/βCyclodextrin (PANI/βCD) composite in addition to electrospinning technique to fabricate modified Cellulose Acetate (CA-PANI/βCD).
Electrospinning is a simple technique for coating PANI/βCD with CA to increase the functional groups of the newly adsorbent.
Adsorbents were characterized by using different techniques like, Fourier Transform infrared analysis (FT-IR), Thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM) and surface area determination.
The three adsorbents PANI, PANI/βCD and PANI/βCD-CA (mod. CA) were compared according to their potential capabilities for the adsorptive removal of phenol and MB from aqueous solution and simulated wastewater samples by using batch technique. The optimum experimental conditions for the removal of phenol and MB were identified in the form of 8.0 as the pH condition at optimum contact time (60 min for phenol and 50 min for MB dye).
The prepared adsorbents were carried out on simulated wastewater samples and excellent results were obtained reached up 90 % for phenol and MB.
The outlined results in this study confirmed that mod. CA nanofibers are the most highly effective adsorbent for the removal of phenol and MB rather than PANI and PANI/βCD composite. The high adsorption capacity of our prepared mod. CA nanofibers than PANI and PANI/βCD composite may be attributed to the higher surface area of mod. CA nanofibers than PANI and PANI/βCD composite also a diversity and good contribution of functional groups on the surface of the electrospun membrane, which can capture phenol and MB molecules with high capacity than PANI and PANI/βCD composite.
Various kinetic models were used in order to understand the mechanism of the adsorption process like: pseudo-first-order, pseudo-second-order, intra-particle diffusion and Elovich. Besides, for determining the maximum adsorption capacity of adsorbate, affinity and selectivity for ions, three equilibrium isotherms namely; Langmuir, Freundlich and Temkin, were applied.
2. Conclusions:
from the obtained results, the main conclusions can be summarized as follows:
• The XRD analysis indicated that the hydrophobic cavity of βCyclodextrin is still free after the interference with Polyaniline which is important in the improvement of the removal efficiency of the phenolic compounds and dyes by formation of inclusion complex (Host-Guest) mechanism.
• The SEM images showed that the optimum percentage ratio of the mod. CA composite for nanofibers formation is (CA 15 % : PANI 0.5 % : βCD 0.5 %) and beads formation is observed at the percentage ratio (CA 15 % : PANI 0.75 % : βCD 0.75 %).
• The removal percentage of phenol and methylene blue dye improved with increasing the contact time. About 90 and 86 % of phenol and methylene blue were adsorbed at optimum contact time (60 and 50 min for phenol and MB dye, respectively). This high removal percentage could be attributed to the high diffusion rate of the adsorbed ions from the bulk of the solution to the adsorbent surface.
• An increase of phenol and methylene blue ions uptake was observed with increasing the initial pH (range 2-12). The highest removal percentage reached at pH 8.0 which selected as an optimum initial pH value.
• Increasing the adsorbent dose led to increase the adsorption of phenol and methylene blue ions that could be attributed to the availability of larger surface area and more adsorption sites by increasing the adsorbent dose. The optimum dose for pollutants removal was chosen as 50 mg for phenol and 80 mg for MB dye.
• The removal percentage of phenol and MB dye ions decreased considerably by increasing the initial adsorbate ions concentration in the removing solutions.
• The adsorption kinetics of phenol and MB dye ions are best approximately by the pseudo-second-order model with an agreement between qe experimental and qe calculated and high correlation coefficient (R2 = 0.99).
• The adsorption isotherm of phenol and MB dye ions are best approximately by the Langmuir isotherm model with an agreement between qe experimental and qe calculated and high correlation coefficient (R2 = 0.99).
3. General Conclusions:
The different adsorbents (PANI, PANI/βCD and PANI/βCD-CA adsorbents) used in this study have the following behavior:
• The main process of sorption is chemisorption, where the adsorption kinetics of ions is best approximately by the pseudo-second-order model.
• At optimum conditions for each sorbent, the removal efficiency of three adsorbents follow the order; PANI < PANI/βCD < PANI/βCD-CA adsorbents that agree with increasing specific surface area.