الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The present thesis is divided into five chapters:
Chapter One: Introduction
The first chapter presents an introduction that includes the sources of water and water consumption in Egypt, sources of water pollution, heavy metal pollution and its impact on human health. Also, it includes the treatment methods of contaminated water from heavy metals by adsorption process and other techniques. This chapter also displays hydrogels as efficient adsorbents for heavy metals removal, different properties of hydrogels and its application, synthesis of different CMC hydrogels, preparation of different hydrogel composites and its advantageous properties and applications.
Chapter Two: Experimental
This chapter presents the experimental part of this thesis. The chemicals, materials, solutions and their resources are reported in this chapter. The procedures for synthesis and preparation of different CMC hydrogel sorbents are illustrated. The used instrumentations and techniques are also described including FT-IR spectrophotometer, x-ray diffraction pattern (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM). This section also reported all the technical procedures for diverse controlling factors during the adsorption process and application on removal of studied heavy metals from tap water and wastewater samples.
Chapter Three: Results and Discussion
The third chapter demonstrates the results and applications of the designed adsorbents for extraction and removal of some selected metal ions and includes two main sections
The first section focuses on the synthesis, AAc/CMC, magnetic AAc/CMC, AAc/CMC-TiO2, AAc/CMC-EDTA and AAc/CMC-Ag hydrogels by gamma irradiation and characterization of prepared hydrogels using several instrumental techniques such as FT-IR, scanning electron microscope (SEM), x-ray diffraction pattern (XRD) and transmission electron microscope (TEM). The collected results confirm the successful synthesis of modified CMC hydrogels via free radical crosslinking copolymerization with gamma irradiation to develop AAc/CMC, magnetic AAc/CMC, AAc/CMC-TiO2, AAc/CMC-EDTA and AAc/CMC-Ag sorbents. All the synthesized hydrogel sorbents are characterized to exhibit a good swelling behavior and some sorbents are prepared in the nanoscale having large surface area and good sorption properties.
The Second section of this chapter displays the results and discussion of sorption studies of selected metal ions, the kinetic studies and adsorption isotherm of the adsorption process in addition to the potential applications of the newly modified CMC hydrogel sorbents for extraction of metal ions from real samples such as tap water, and wastewater and this section include two main parts.
The first part describes the various experimental parameters affecting the sorption capacity of Cu(II), Cd(II), Zn(II) and Pb(II) by hydrogel sorbents such as solution pH, contact time, sorbent dosage, initial metal ion concentration and presence of competitive ions.
The metal capacity values were determined in the pH range (1.0-7.0). The order of metal capacity values (μmolg-1) can be summarized according to the following orders:
AAc/CMC : Cu(II) > Pb(II) > Cd(II) > Zn(II)
magnetic AAc/CMC : Pb(II) > Cu(II) > Cd(II) > Zn(II)
AAc/CMC-TiO2 : Pb(II) > Cu(II) > Cd(II) > Zn(II)
AAc/CMC-EDTA : Cu(II) > Pb(II) > Cd(II) > Zn(II)
AAc/CMC-Ag : Pb(II) > Cu(II) > Cd(II) > Zn(II)
The effect of contact time or shaking time is also studied in presence of the optimum conditions of pH for each metal ion and at different contact times (1-60 min). The optimum contact time for most metal ions are identified as 30-50 min and the order of metal ions corresponding to its metal capacity values (μmolg-1) can be summarized according to the following orders:
AAc/CMC : Cu(II) > Pb(II) > Cd(II) > Zn(II)
magnetic AAc/CMC : Pb(II) > Cu(II) > Cd(II) > Zn(II)
AAc/CMC-TiO2 : Cu(II) ≥ Pb(II) >Cd(II) > Zn(II)
AAc/CMC-EDTA : Cu(II) > Pb(II) > Cd(II) > Zn(II)
AAc/CMC-Ag : Pb(II) > Cu(II) > Cd(II) > Zn(II)
The effect of sorbent dosage on the sorption properties of all hydrogel sorbent is also studied and evaluated by using the optimum buffer conditions and contact time. The optimum sorbent dosage is found to be 5 mg and the metal capacity values (μmolg-1) can be summarized according to the following orders:
AAc/CMC : Pb(II) > Cu(II) > Cd(II) > Zn(II)
magnetic AAc/CMC : Pb(II) > Cd(II) > Cu(II) > Zn(II)
AAc/CMC-TiO2 : Cu(II) > Pb(II) > Cd(II) > Zn(II)
AAc/CMC-EDTA : Cu(II) > Pb(II) > Cd(II) > Zn(II)
AAc/CMC-Ag : Pb(II) > Cu(II) > Zn(II) > Cd(II)
The effect of metal ion concentration on the sorption process using hydrogel sorbents is studied under optimum condition of pH, contact time and sorbent dosage for each metal ion. The highest metal capacity values can be summarized according to the following orders in presence of initial metal ion concentration:
AAc/CMC : Pb(II) > Cu(II) > Cd(II) > Zn(II)
magnetic AAc/CMC : Pb(II) > Cu(II) > Cd(II) > Zn(II)
AAc/CMC-TiO2 : Pb(II) > Cu(II) > Cd(II) > Zn(II)
AAc/CMC-EDTA : Pb(II) > Cu(II) > Cd(II) > Zn(II)
AAc/CMC-Ag : Pb(II) > Cu(II) > Cd(II) > Zn(II)
The effect of interfering ions on the sorption of Cu(II), Cd(II), Zn(II) and Pb(II) using studied sorbents is also investigated in presence of other competing metal ions, such as NaCl, Na-acetate, KCl, KNO3 and NH4Cl. These ions are found to exhibit either no effect, decreased or improved sorption capacity depending on the type of interfering ion, hydrogel sorbent and adsorbed metal ion.
The second part discusses The potential application of hydrogel sorbents for removal of Cu(II), Cd(II), Zn(II) and Pb(II) from real aqueous solution and samples. The results of this part refers to the high efficiency of the designed CMC based hydrogel sorbents for removal of Cu(II), Cd(II), Zn(II) and Pb(II) from water samples providing the range of percentage extraction of these ions as 87.8-98.2, 53.1-96.8, 11.7-95.5 and 76.3-98.9, respectively.
Chapter Four: Conclusion
This chapter outlines our findings and conclusion based on the collected results from this study.
Chapter Five: References
This chapter contains list of references that were cited in this thesis.