الفهرس 
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Abstract
nvironmental pollution, as a consequence of the
industrialization process, is one of the major problems that
has to be solved and controlled. The most important treatment
processes for metals and dyes contaminated waste streams include
chemical precipitation, membrane, filtration, ion exchange, carbon
adsorption and coprecipitation/adsorption. However, all these
techniques have their inherent advantages and limitations in
applications. These processes usually need expensive facility and
high maintenance cost. Therefore, there is a need for more
economical alternative technologies for the treatment of metals
and dyes contaminated waste streams.
T he aim of present work is to study the treatment of some
hazardous substances such as heavy metals e.g. ( lead, cobalt and
strontium) and dyes e.g. ( acid red 73, and acid blue 74 ) using
either adsorption or liquid emulsion membrane techniques.
T h e experimental part deals with the application of
adsorption and liquid emulsion membrane techniques for removal
of some hazardous substances such as metal ions ( ead, cobalt
and strontium) and dyes (acid red 73 and acid blue 74). All the
apparatus and techniques employed were described.
In the adsorption technique, 23 samples of activated
carbons were prepared by either physical or chemical methods
using bone char as precursor. In this concern, activated carbon
prepared as follows: (i) by physical activation (either steam or N2 gas ); (ii) by chemical activation either by mineral acids
(HCl, HNO3, H2SO4 and H3PO4) or strong alkalies (KOH and
NaOH) or organic compounds (sodium dodecyl sulphate)
(SDS) were prepared. Sorption behavior of 5- adsorption
systems were examined. These are: BC-SDS-2105: Pb,
BC-S-2750 : Co, BC-N2-2500 : Sr, BC-SDS-2105: acid red 73
and BC-SDS-2105: acid blue 74 and the factors affecting
adsorption process were described. In liquid emulsion membrane
technique, the extraction of Co(II) ions using Cyanex 301 as
extractant in cyclohexane from nitrate medium was investigated
to determine the suitable conditions for the permeation of Co
(II) ions by the membrane used. The factors affecting the stability
of the prepared liquid emulsion membrane was studied in terms
of leakage percent at different parameters. The factors affecting
the permeation process for Co(II) ions were also investigated.
T he results of the first part of this study describes the
physicochemical and adsorption properties of the 24-activated
carbons derived from bone char and prepared by physical or
chemical activation methods. In this concern, characterization
of the used five adsorbents in our applications exhibited bulk
density greater than 0.25 g/cc. i.e. the value of density reported
by American Water Works Association (AWWA) as the lower
limit of activated carbon of the bulk density to be of practical
use. The high ash content of activated carbons made from bone
char can be explained by their high specific mineral content,
especially their richness in silica (SiO2), iron oxide (Fe2O3 magnesium oxide (MgO), and calcium oxide (CaO) and
phosphorous oxide (P2 O5).
from N2 isotherms, samples activated by physical
activation, (BC-N2-2500) had the highest surface area (117.71
m2/g) with the highest pore volume (0.1cc/g) and possess a
mesopore volume representing 56 % of the total pore volume.
This is due to nitrogen as activating agent instead of steam in
physical activation is felt in terms of two competing mechanisms,
namely, micropore formation and pore widening. In case of
steam activation, sample BC-S-1750 is essentially a
mesoporous carbon, as the mesopore content reaches a value of
73 % of total pore volume and BET surface area of 27.03 m2/g .
But in case of sample BC-S-2750, micropores and mesopores
formation are the dominating mechanisms as the mesopores
content represents 52 % of the total pore volume with surface
area of 48.93 m2/g. This means that by increasing the hold
time, the surface area increases and mesoporesity decreases.
In case of chemical activation, it was found that using sodium
dodecyl sulphate in sample BC-SDS-2105 gives active carbon
with the highest surface area of 81.90 m2/g and highest
mesoporesity of 76% but using potassium hydroxide in sample
BC-K70%-1500 gives the lowest surface area of 3.19 m2/g and
low mesoporosity of 54 %.
The scanning electron microscopy (SEM) images of bone
char samples before and after activation, showed relatively
heterogeneous morphology of particles and channels. The particles had irregular shapes with edges and corners. The
FTIR spectra of the bone char samples indicated a series of
bands in the mid-infrared region. These bands can be divided
into three main categories associated with phosphate, carbonate
and hydroxyl groups. On the basis of pH measurement, the
prepared carbons show slightly basic surfaces (pH = 7.85 -
10.43).
In the second part of this investigation, the untreated
bone char and the prepared activated carbons were tested for
removal of lead, cobalt, strontium, acid red 73 and acid blue 74
from aqueous solution. BC-S-2750 and BC-N2-2500 carbons
were found to be the most effective in removal of cobalt and
strontium; respectively. BC-SDS-2105 carbon exhibited the
highest capacity for removal of lead, acid red 73 and acid blue
74 compared to the other carbons. Factors affecting adsorption
process proved that the reaction rate was fast, requiring only a
short contact time for metals ( lead, cobalt and strontium ) but
the rate was slow, requiring long contact time for dyes (acid
red 73 and acid blue 74). The equilibrium steady state was
reached at 120, 60, and 120 min. for lead, cobalt, and
strontium; respectively. In case of acid red 73 and acid blue
74, the equilibrium was attained after shaking for about 48 hrs.
The pseudo-first and second order kinetic models were applied.
For lead and cobalt the calculated qe (equilibrium adsorption
capacity) values obtained from pseudo-second order rate
expression are in good agreement with the experimental data
(qe,exp). In case of strontium, the pseudo-first order kinetic model is the predominant due to the calculated value qe, agrees
very well with the experimental data qe,exp.
The kinetic data of the dyes can be described well by
second order rate equation due to the high values of
correlation coefficient R2 for second order adsorption model
compared to that of pseudo-first order model and the
calculated equilibrium adsorption capacities (qe,cal) from second
order model agree well with the experimental values. These
results suggest that this sorption system is not first order
reaction and the rate-limiting step may be chemical sorption.
The linear portion of the curves of qt vs. t0.5 plots for all
studied sorption systems do not pass through the origin point.
This proved that the intra-particle diffusion was not the only
rate-controlling step. The sorption mechanism of these sorption
systems from aqueous solution is rather a complex process,
probably a combination of external mass transfer and intraparticle
diffusion which contribute to the rate determining step.
The adsorption edge for Pb (II) was found in the pH range 2-
5. While the adsorption edge was found in the pH range 2-6
for Co (II) and that of Sr (II) was found in the pH range 2-8.
T he adsorption isotherms such as Langmuir (L),
Freundlich (F) and Dubinin-Radushkevich (DR) were used to
model the experimental data.
All the adsorption studied systems followed the Dubinin-
Radushkevich (DR) model. from the DR isotherm parameters,
the E-values obtained in case of cobalt and strontium adsorption are in the energy range of an ion-exchange reaction i.e., 8-16
kJ/mol. But the value of lead sorption free energy indicated that
lead is adsorbed by physisorption i.e., (20-40 kJ/mol). In case of
acid red 73 and acid blue 74, the E-values obtained are in the
energy range 52.99-133.63 kJ/mol, i. e. acid red 73 and acid blue
74 are adsorbed by hemisorptions. The thermodynamic
parameters of lead, cobalt, strontium, acid red 73 and acid blue 74
were calculated. The data indicat that lead, cobalt, strontium and
acid blue 74 sorption are better occurred at higher temperature
while acid red 73 sorption is not affected by increasing
temperature.
T he third part is concerned with the use of liquid
emulsion membrane technique in removal of Co (II) ions from
aqueous solution. In this part, the permeation of cobalt (II) ions
from aqueous solution by a liquid emulsion membrane
containing Cyanex-301 in cyclohexane was experimented based
on liquid-liquid extraction studies. The effect of nitric acid
concentration from 0.01 to 2.0 M on the extraction of Co was
studied. It was found that, the extraction percent of cobalt
decreases with increasing nitric acid concentration. HCl was
found to be the best stripping agent for cobalt ions from
Cyanex 301 as compared to H2SO4, H3PO4, HNO3 and NaOH
and the stripping efficiency of Co(II) increases with increasing
the concentration of HCl from 0.01 to 5 M. The extraction
percent of Co ions increases with increasing the shacking time
and the extraction was very fast and the maximum extraction
percent obtained was 90 % after 15 m The increase in the amount of carrier concentration
leads to an increase in the extraction percent of Co(II) ions.
Slope analysis showed that cobalt ions extracted as MB2. The
stability of the prepared LEM in nitric acid medium was studied
using the different surfactants (Span80, Arlacel A and
Sesquioleate ). It was found that Span 80 gives the most
stable emulsion compared with ArlacelA and Sesquioleate. The
effect of Span 80 concentration on the stability of emulsion
globules was studied. It was found that, the stability of LEM
increases with increasing the surfactant concentration from 2 to
6 % ( v/v).
The factors affecting the permeation of cobalt were studied
and lead to the following:
•The permeation percent of cobalt ions decreases with
increasing the nitric acid concentrations in the external
aqueous phase.
•the permeation percent of cobalt ions increases with
increasing Cyanex 301 concentration.
•The permeation percent of cobalt ions decreases with
increasing the initial concentration of cobalt ions in the
external aqueous phase.
•The permeation percent of cobalt ions has insignificant or
slight increase when HCl concentration increased in the rang
3-5 M. from these data, the rate of Co(II) permeation at 25 0C at
a ratio of membrane to external phase volume of 0.1 can be
represented by the following relation:
d[C]per /dt= K[HNO3]-1 [Co (II)]-1.5 [CYANEX 301]1 [HCl]0.12
where [C]per is the concentration of the permeated Co(II)
and K is a constant.