الفهرس 
SUMMARYOnly 14 pages are availabe for public view
 |  | from | 178 |  |  |
| | | from | 178 | | |
Abstract
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 chitosan as an efficient adsorbent for heavy metals removal, different
properties of chitosan and its application, synthesis of nano-chitosan, modification of
chitosan 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 nano-chitosan and modified nano-chitosan
sorbents are illustrated. The used instrumentations and techniques are also described
including FT-IR spectrophotometer, scanning electron microscope (SEM), thermal
gravimetric analysis (TGA), high resolution transmission electron microscope (HRTEM),
atomic absorption spectroscopy and spectrophotometric analysis of Hg(II).
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 characterization of synthesized chitosan nanoparticles,
nano-Ch-13 and nano-Ch-15 and the modified nano-chitosan, nano-Ch-Cn-
13, nano-Ch-Cn-15, nano-Ch-Ac-13 and nano-Ch-Ac-15 using several instrumental
techniques such as FT-IR, TGA, scanning electron microscope (SEM) and high
resolution transmission electron microscope (HR-TEM). The collected results confirm
the successful synthesis of nano-chitosan and its modification by cinnamaldehyde and
acetophenone via Schiff’s base condensation reaction to develop four new modified
nano-sorbents, nano-Ch-Cn-13, nano-Ch-Cn-15, nano-Ch-Ac-13 and nano-Ch-Ac-15
sorbents. All the synthesized nano-chitosan sorbents exhibited good thermal stability
and nano size in the range of 3.96-17.92 nm.
The Second section of this chapter displays the results and discussion of sorption
studies of selected metal ions and the potential applications of the newly modified
nano-chitosan sorbents for extraction of metal ions from real samples such as tap
water, sea water and industrial wastewater and this section include two main parts.
ii
The first part describes the various experimental parameters affecting the sorption
capacity of Cu(II), Cd(II), Hg(II) and Pb(II) by nano-chitosan 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:
Nano-Ch-13 : Pb(II) > Cu(II) > Cd(II) > Hg(II)
Nano-Ch-Cn-13 : Cu(II) > Pb(II) > Hg(II) > Cd(II)
Nano-Ch-Ac-13 : Cu(II) > Pb(II) > Hg(II) > Cd(II)
Nano-Ch-15 : Cu(II) > Pb(II) > Hg(II) > Cd(II)
Nano-Ch-Cn-15 : Cu(II) > Pb(II) > Hg(II) > Cd(II)
Nano-Ch-Ac-15 : Cu(II) > Cd(II) > Hg(II) > Pb(II)
The effect of contact time or shaking time was 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 were identified as 30 min and the
order of metal ions corresponding to its metal capacity values (μmolg-1) can be
summarized according to the following orders:
Nano-Ch-13 : Pb(II) > Cu(II) > Hg(II) > Cd(II)
Nano-Ch-Cn-13 : Cu(II) > Pb(II) > Hg(II) > Cd(II)
Nano-Ch-Ac-13 : Cd(II) > Pb(II) > Hg(II) > Cu(II)
Nano-Ch-15 : Cu(II) > Pb(II) > Hg(II) > Cd(II)
Nano-Ch-Cn-15 : Pb(II) > Cu(II) > Hg(II) > Cd(II)
Nano-Ch-Ac-15 : Cd(II) > Hg(II) > Cu(II) > Pb(II)
The effect of sorbent dosage on the sorption properties of all chitosan nanosorbent
was also studied and evaluated by using the optimum buffer conditions and
contact time. The optimum sorbent dosage was found as 5 mg and the metal capacity
values (μmolg-1) can be summarized according to the following orders:
Nano-Ch-15 : Pb(II) > Cd(II) > Cu(II) > Hg(II)
Nano-Ch-Cn-13 : Cu(II) > Hg(II) > Pb(II) > Cd(II)
Nano-Ch-Ac-13 : Hg(II) > Pb(II) > Cu(II) > Cd(II)
Nano-Ch-15 : Pb(II) > Cu(II) >Cd(II) > Hg(II)
Nano-Ch-Cn-15 : Pb(II) > Hg(II) > Cd(II) > Cu(II).