الفهرس 
Agricultural Wastes ProblemsOnly 14 pages are availabe for public view
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Abstract
Agricultural wastes represent a problem to the Egyptian environment. In
the first and second chapters, it is exposed the environmental waste in
Egypt and exposed amount in future. In literature review the suggestions
to utilize these agricultural wastes were explained. One of valuable use is
preparation of activated carbonsto be used for removing the pollution
from air and water.
In this thesis, OP and PK as environmental wastes are successfully
turned to activated carbon to be used in pollution treatment. OP is dried
and milled then burned and physically activated in one-step at 550 oC.
PK is carbonized and activated in two separate steps. Activation process
was made physically using water vapor. The yield percentage for PKAC
was 15.30% and for OPAC was 29.86%.
Characterizations are made for prepared activated carbons (ACs). The
percentage moisture content varied from 2.94 - 10.50 %. Percentage
volatile matter content varied from 42.51- 79.87 %. Percentage ash
content varied from 0.490 to 10.651 %. Apparent density varied from
0.508 to 0.565 g/cm3. Pores volumes varied from 0.525 – 0.573
cm3/cm3. The iodine number for non-activated PK carbon samples was
254.80 - 344.90. The iodine number for activated PK carbon samples
were 370.16 for granules and 507.60 for powder. The iodine number for
orange peel activated carbon (OP AC) samples were 354.50 for granules
and 520.50 for powder.
The surface areas by multi-point BET of PK were 26.009 and 40.277
m2/g for non-activated and activated respectively. The surface areas by
one point BET of OP were 0.2708 and 0.3699 m2/g for non-activated and
activatedrespectively.
Increase of surface area caused increased adsorption of iodine. Increase
of temperature of activation decreased the yield but increased the pores
and surface adsorptive power. Moisture and ash contents played an
important role for adsorption of iodine on the prepared ACs. Therefore
we can conclude that more moisture and ash contents increased the polarity to adsorb more iodine. SEM imaging proved the existence of
meso and macro pores.
The adsorption process of iodine followed both physical and chemical
types. On PKAC followed more Langmuir than Fruindlich. Whereas on
OPAC followed Fruindlich more than Langmuir.
The thesis described the methods of preparation of activated carbon from
peach kernel (PK) and orange peel (OP) as examples of environmental
wastes. The activated carbon was prepared either in one step or in two
separate steps of carbonization and activation at 550 & 600 oC. The
physical activation was performed by water vapor. The mechanism of
adsorption varies from physical and chemical adsorptions. The
Fruendlich and Langmuir equations were determined.
The yield of produced activated carbon for PK samples was 36.82 % at
550 oC and 15.30 % at 650 oC. The yield of produced activated carbon
for OP samples was 29.18 % at 550 oC.
SEM image of peach kernel activated carbon (PK AC) show that the
surfaces are irregular in spherical shape with average diameter of (5-16)
μm. Also macro pores also exist with diameters of greater than 50 μm.
SEM image of OP AC showed the surface were irregular in spherical
shape with average diameter of (18-42) μm for granules and some degree
of porosity. The size of pores of powdered OP AC ( 9- 21) μm less than
of granules (18-42) μm. There are also macro pores of diameters greater
than 50 μm.
The adsorption of iodine on PK AC followed both more chemical with R²
= 0.9498 (a= 0.3877 & b= 0.3225) rather than physical with R² = 0.8419
with (n=1.4428 & k= 1.1951). The adsorption of iodine on OPAC
followed both more physical with R² = 0.7356 with (n=0.6926 & k=
36.3502) than chemical with R² = 0.5923 (a= 0.1387 & b= 1.4260).