الفهرس 
Activated CarbonsOnly 14 pages are availabe for public view
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Abstract
This work deals with the economic utilization of local
available agricultural by-product that is olive stone. Converting this raw material (olive stone)
to produce activated carbons with high ability for adsorption of organic and inorganic pollutants
from different aqueous media (as surface water, underground water and/or industrial waste water).
The work in this thesis deals with the study of the sorption behavior of the elements La (III) and
Ce (III) from nitrate solution on activated carbon that prepared from olive stone as agricultural
by-product. Olive stone was chosen as a raw material for many reasons: (i) It is a highly abundant
renewable by-product. (ii) It needs no primary grinding stage, with high mechanical
strength.
An introductory part focused on activated carbon materials from different points of view:
properties, structure, porosity, classification and sources. This chapter describes also the
essential schemes used for production of the activated carbon through two routes, thermal (or
physical) activation route by using steam or via steam pyrolysis. The second route is the chemical
activation using phosphoric acid and nitric acid or potassium hydroxides.
Also, the chapter includes a detailed survey of the
methods employed in the characterization of activated carbon like, porosity, its creation and its
properties using N2-gas adsorption at 77K. The analysis of the N2-adsorption isotherms was
described using BET. The sorptive properties of the activated carbon depend not only on the
porosity but also on the surface chemical composition, and the ash content of the carbons.
A part of this chapter includes a literature survey deals with different precursors for the
activated carbon production, the criteria which considered when choosing a carbonaceous activated
carbon and finally a various applications of the activated carbon.
Based on the above mentioned background, the experimental part of this thesis was designed with
respect to activation schemes and methods of material characterization. Two single – step methods
activation were thus selected for adsorbent production; these are the ”steam pyrolysis” and the
”H3PO4 –activation” routes. These two processes favorite especially during the last decade, as they
save both energy and time, produce high – carbon yields and good adsorbing carbons are obtained
under controlled condition.
The third part displayed the results and their discussions and
involves three sections:
First section. This section indicates the characterization of the carbons. It describes the physico
chemical nature of the prepared activated carbons derived from the olive stone and prepared by
”steam pyrolysis”,HNO3 and H3PO4- activated routes. In this concern, the physical properties of
various carbons cover the estimation of apparent and packed density, yield and ash content,
burn-off, scanning electron microscopy (SEM), pore structure characterization through nitrogen
adsorption isotherms. The chemical properties of various carbons cover the estimation of pH,
Fourier- transform infrared spectroscopy (FTIR), elemental analysis.
All products exhibited low apparent and bulk density (around 0.23 g/cm3). Samples treated by H3PO4
give higher carbon-yield than the samples treated by steam pyrolysis. These samples treated with
H3PO4 contain enhanced ash beside the residual phosphorous oxides, leading to the observed high
packed density and ash content.
FTIR analysis indicated the presence of –CH, –CH2, – OH of hydroxyl functional groups, alcohol and
carboxylic groups and ketone in most samples.
Second section of this chapter, the activated carbons
were tested for removal of crystal violet, we found that
OSK8 was the superior in removal of CV.
The adsorption isotherms such as Langmuir, Freundlich were used to model the experimental data. We
found that the data fitted to Freundlich.
The pseudo first, second order and Interapaticle Diffussion kinetic models were applied. The
adsorption of CV follows the second order equation indicating the chemisorption control. The
thermodynamic parameters of CV are calculated.
The third section: The activated carbons were tested for removal of Lanthanum and cerium ions from
nitrate solution.OSPA58 carbon was found to be superior in removal of Lanthanum and Cerium. The
adsorption followed the Langmuir in case of Lanthanum, while the adsorption followed by Freundlich
in case of Cerium. The pseudo first, second order and Interapaticle Diffussion kinetic models
were applied. The adsorption of La(III) and Ce (III) follows the second order equation indicating
the chemisorption control. The thermodynamic parameters of La (III) and Ce (III) are calculated.
The OSPA58 was modified by crystal violet (CV). and
60 % carbon di sulphide (CS2).and we found that the % removal of La (III) and Ce (III) in case of
60 % carbon disulphide was more than in case of OSPA58 alone or when modified by CV.
By study the behavior of adsorption of La (III) and Ce (III) in the single and binary system
we found that, the amount of adsorption in case of binary system was lower than in case of
single system, due to the interference between the adsorbent molecules onto the adsorbed surface.
from the Economical comparison between commercial activated carbon and the prepared activated
carbon from olive stone (no cost and agriculture waste), we found that, the cost of the activated
carbon which prepared from olive stone by thermal treatment only was 80 L.E, by physical activation
(pure water steam) was 120L.E, by chemical activation which impregnated by 50% nitric acid
was 195 L.E, by chemical activation which impregnated by 50% phosphoric acid was 200 L.E and by
chemical activation which impregnated by 50% potassium hydroxide was 215 L.E and the price of
commercial activated carbon was 825 L.E per Kilo gram, this mean that the activated carbon
which prepared from olive stone was more economic than the commercial carbonFinally, olive stone an available and low-cost
agricultural by-products, have been used for the production of activated carbons of satisfactory
quality using one-step steam activation and phosphoric acid as chemical activant. The resulted
activated carbons have different physical and chemical properties depending on activation
temperature,.
On the basis of this study it is concluded that the widely available olive stone as a
precursor has good capacity as a cheap and effective scavenger for adsorption from aqueous solution
towards organics (phenol, para nitro phenol, methylene blue and crystal violet) as well as
inorganics (La(III) and Ce(III) ions). Thus, it can be effectively used for water treatment and
environmental waste management.