الفهرس 
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Abstract
English Summary
Title: ”Chemical Studies on the Removal of Some Heavy Elements
from Aqueous Solutions by Modified Pottery Materials”
In this study it is intended to benefit from the use of low cost
Egyptian pottery materials supplied from different sources for removal
of selected heavy elements namely; cesium, barium, cobalt and copper
from aqueous solutions. The thesis is divided into three main chapters
including: chapter 1, the introduction, chapter 2, experimental and
chapter 3, results and discussion.
Chapter-1: Introduction
The introduction includes brief account related to the
environmental impact of the selected heavy metals. Descriptions of
pottery materials as low cost adsorbents include raw and modified
pottery materials. This part also includes adsorption process definition
and its types of chemisorption and physisorption. It also contains a
brief account about the different adsorbents used for removal of
cesium, barium, cobalt, and copper from their aqueous solutions.
Finally, the chapter ended with a literature survey on the adsorption of
Cs(I), Ba(II), Co(II) and Cu(II) using clay, clay minerals as well as
pottery materials.
Chapter-2: Experimental
The experimental part, defines the chemicals and standards used,
as well as pottery materials used and the different methods applied for
its physical and chemical characterization. It also includes procedures
of measuring cation-exchange capacity, pH, loss of ignition and
moisture content. The batch adsorption techniques used includes the
effect of shaking time, pH, particle size, the concentration of inactive
cesium, barium, cobalt and copper, adsorbent weight and temperature
are also given.
A brief description for ICP-OES instrument that used to determine
metal ions concentration is given. In addition to other instruments used
for characterization of pottery materials are also described. The sources
and data of the pottery materials investigated are given in the following
table as given in Table (3.1).
Firing Source
Temperature
(°C)
Sample Code
Village Alfakhareen, Pottery
House Abdeen, Ancient Egypt,
Al-Fostat, Cairo Governorate.
Aswan Powder AP ----
Aswan Fired AF 900 - 1100
Ezbet Elnamooss, Samannoud
City, El-Gharbeya Governorate.
Black Powder BP ----
Black Fired BF 800 -900
Village Alfakhareen, Pottery
House Abdeen, Ancient Egypt,
Al-Fostat, Cairo Governorate.
White powder WP ----
White Fired WF ≈1200
Chapter-3: Results and discussion
This chapter includes results and related discussion of physical
and chemical characteristics of pottery materials and the data of
adsorption of selected heavy elements on these materials. This chapter
is divided into five parts;
Part 1: include physical and chemical properities of pottery materials.
It is obvious that the pH values of AP.AF, BP, WP and WF as
determined in the experimental, are very close to each others but for
BF, the pH increase after ignition from 6.8 to 8.4. CEC is found to be
(28.0, 14.0, 27.0, 25.0, 18.0 and 16.0 meq/100g) for AP, AF, BP, BF,
WP and WF, respectively. It is observed that black powder (BP) has the
highest surface area compared to other samples The XRD analysis of
pottery materials indicates that the mineral constituent is kaolinite,
quartz, hematite, anatase, albite, calcite and montmorillonite.
The XRF data indicated that the percent of silicon to aluminum for
each clay mineral was similar to the theoretical formula of these kinds
of clays, 2:1 for montmorillonite and 1:1 for kaolinite. Chemical
analysis of all types of pottery materials revealed a relatively high Ca,
Mg, Na and K percent, in which these ions can be exchanged easily
with other ions without affecting the clay mineral structure.
IR spectra showed that all samples exhibit absorption bands in the
range of 400-4000 cm−1 according to each type of minerals present in
each material of all pottery materials. The data of IR confirms the data
of XRD.
Part 2: The second part of results and discussion includes the sorption
studies of Cs, Ba, Co and Cu on the six pottery materials. According to
sorption studies, this chapter includes results and discussion related to
the study of the different parameters affecting on heavy elements
adsorption. The shaking time necessary to reach equilibrium was 2hr.
But from the data, it could be seen that further increase in the shaking
time beyond the 2hr for each ion resulted in a slight increase in the
removal percentage.
The optimum pH condition was found to be 7.0 for a maximum
removal of cesium and barium on all pottery materials, 6.0 for cobalt
and 5.0 for copper. The optimum shaking time was determined as 120
minutes for removal of Cs+, Ba2+, Co2+ and Cu2+ from aqueous
solutions. For cesium the order of removal is:
BP(67%)>AP(54%)>WP(49%)>AF(42%)>BF(38%)>WF(36%).
The order of removal (%) of barium under is:
BP (74%)>AF (65%) >AP =BF (55%)>WF (48%) >WP (37%)
For cobalt the order of removal (%) is:
WF (82%)>BP (60%)>AP (45%)>AF (36%)>WP (35%)>BF(32%)
The order of removal (%) for copper is:
WF(95 %)>BP(85%)>AF (51%)>AP (48%)>BF (45%)>WP (35%)
The optimum particle size for all pottery materials was found to be
250 mesh for a maximum removal of cesium, barium, cobalt and
copper by all pottery materials. The optimum weight of all pottery
materials was found to be 0.2 g for a maximum removal of cesium,
barium, cobalt and copper by all pottery materials.
Part 3: includes the results of applying different empirical fitting
models, which allow the systematic description of the influence of
different conditions on selected ions behavior. These models include
empirical adsorption isotherms such as Langmuir and Freundlcih.
According to the isotherm models, the adsorption pattern of Cs+,
Ba2+, Co2+ and Cu2+ on AP, AF, BP, BF, WP and WF were found to fit
well with the Langmuir model. This model also assumes a chemical
adsorption.
Part 4: contains the kinetic modeling, it is found that the pseudosecond
order adsorption model is more suitable to describe the
adsorption kinetics of Cs+, Ba2+, Co2+ and Cu2+ ions on all pottery
materials studied. It is clear that the experimental adsorption capacity
(qe, experimental) and theoretical adsorption capacity (qe, calculated)
values are in good match for second order model where for first order,
they are different.
Part 5: it investigates the sorption of Cs(I), Ba(II), Co(II) and Cu(II)
by the fired pottery pots and its desorption. In this concern, three
pottery pots representing the fired products of pottery materials i.e.
Aswan pot, black pot and white pot are used for adsorption for single
and multielement systems.
The presence of multiple competing ions is more frequent than the
existence of only one kind of ions, and the sorption in multi-component
systems becomes much more complicated due to the competition
between different ions as well as different types of coordination.
Summary and Conclusion
156
The results of desorption studies illustrated that Cs(I) is eluted
from the pottery materials using 0.1N NaOH. On the other hand,
Ba(II), Co(II) and Cu(II) were easily desorbed using 0.1 N HCl
solutions. The desorption of Cs(I) from loaded Aswan pot, black pot
and white pot using NaOH (0.1N) was amounted to 76, 25 and 18 %,
respectively. The highest desorption percents of Ba(II), Co(II) and
Cu(II) from loaded Aswan pot, black pot and white pot using 0.1 N
HCl were 55, 90 and 95 %, respectively.
The desorption of Cs(I) from loaded Aswan pot, black pot and
white pot using DI water, 0.1N NaOH, 0.1N HCl and tap water
attained the order:
NaOH> HCl > DI water > tap water
Also, Ba (II) was desorbed from loaded Aswan pot, black pot and
white pot using DI water, 0.1N NaOH, 0.1N HCl and tap water with
the order:
HCl > NaOH > DI water > tap water
Also, Co (II) was desorbed from loaded Aswan pot, black pot and
white pot using DI water, 0.1N NaOH, 0.1N HCl and tap water with
the order:
HCl > DI water >NaOH > tap water
Finally,The desorption of Cu(II) loaded Aswan pot, black pot and white
pot using DI water, 0.1N NaOH, 0.1N HCl and tap water exhibited the
order:
HCl > NaOH> tap water > DI water
Hydrochloric acid showed the maximum desorption efficiency for
Ba(II), Co(II) and Cu(II) but NaOH showed the maximum desorption
efficiency for Cs(I) only.
Conclusion
The primary goal of the present thesis was to assess the
effectiveness of pottery materials for the removal of selected heavy
metals from solution. This was accomplished through laboratory batch
experiments involving known amounts of crushed pottery materials and
predetermined concentrations of the following heavy metals: Cs, Ba,
Co and Cu. Batch adsorption tests were modelled using both the
Langmuir and Freundlich equations and adsorption kinetics was also
analyzed. Based on the results, the following is concluded:
Batch studies on cesium, barium, cobalt and copper removal
showed significant effects of the variables adsorbent dose,
shaking time, initial metal concentration, pH etc. The results
provide a good indication of the different operating
conditions that would be required for efficient removal of
each heavy metal from aqueous solution.
Raw pottery materials show high adsorption capacity
towards cesium and barium but modified pottery materials
show high capacity towards cobalt and copper.
pH is a significant factor in adsorption processes since it
causes electrostatic changes in the solution. The maximum
removal efficiency for Cs(I) is at pH 7.0 %, for Ba(II) at pH
7.0 for Co(II) at pH 6.0 and for Cu(II) at pH 5.0
Langmuir and Freundlich isotherms were observed to fit the
equilibrium data and the model parameters were calculated at
various temperatures using linearized equations. Langmuir
Summary and Conclusion
158
isotherm model (R2≈1) is in good agreement with the
experimental data as compared to Freundlich model.
Kinetics data were best modeled by a pseudo second order
kinetics equation.
The desorption study was also carried out and showed that
the hydrochloric acid (HCl) 0.1N is the best extractant.
On the light of these data, the pottery materials effectively
and quantitatively remove the studied elements from aqueous
solutions. So, it would be useful to use these sorbents in the
treatment of the waste solutions containing these elements.
Also, it can be regarded as one of the promising materials in
reprocessing and decontamination processes.
Scope for Future Research
The technology, which uses locally available adsorbent
materials like Pottery materials, is extremely low cost,
effective and viable.
Following are the scope for future research:
To explore the possibilities, other modifications or
pretreatments of adsorbent to improve its adsorption
capacity.
Studies with actual industrial or nuclear wastewater to
evaluate parameters for field applications