الفهرس 
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Abstract
Soil and water contamination with heavy metals is a major environmental problem, So
the wide range of techniques such as adsorption have been used to remove heavy metals. The
specific objectives of this study are: 1) Evaluation the effect of burning temperatures of
agricultural waste to obtain the biochar at different temperatures; 2) Estimating properties of
produced biochar by burning the different agricultural wastes; 3) Studying the sorption capacity
of biochar produce at different temperature; 4)Study the effect of adding biochar to the soil on
transport of heavy elements.
The obtained results can summarized as follows:
1. Batch sorption of heavy metals on biosorbents
Eight types of biosorbents (agricultural waste) used for removing the heavy metals in
aqueous solution i.e., rice husk waste (RHW), Bagasse (BG), Sawdust (SD), Wheat Straw (WS),
Beans Straw (BS), Pomegranate Peel (PP), Orange Peel (OP), and Kiwi Peel (KP). Actually, Rice
husk waste; Beans straw; Pomegranate peel and Orange peel are the best bio-sorbents to remove
the heavy metals from aqueous solution. The removal percentage ranged; from 71.3 to 77.5% for
Rice husk waste; from 74.5 to 82% for Beans straw; from 82.3 to 84.9% for Pomegranate peel;
from 74.6 to 82.1% for Orange peel. The present results indicate that Rice husk waste; Beans
straw; Pomegranate peel and Orange peel are the best materials to remove the heavy metals from
the aqueous solution and the pomegranate peel gave the highest percentage of removal (82.31 to
84.96%).
2. Sorption of heavy metals on Biochar
The beans straw, rice husk waste, orange peel and pomegranate peel burned under
oxygen-limited atmosphere to obtain the biochar at different temperatures (350, 450, 550, and
650° C). The adsorption of heavy elements compared to these wastes after burning. The results
indicated that the pyrolysis of biochar at 450C is the best of pyrolysis temperature for adsorption
of heavy metals. The sorption capacity was in the order of Cd > Ni > Pb > Co. In addition, the
ability of the used materials was in the order of Biochar (350Co, 450Co, 550Co, and 650Co) where
the removal percent was 89.33, 98.79, 88.45 and 68.36%, respectively.
3. Sorption of heavy metals on Pomegranate Peel Biochar
The results indicate that biochar production from pomegranate peel at a temperature of
450°C has a high ability to absorb heavy metals from the aqueous solutions. The removal
percentage 99.82 % for Pb; 97.64 % for Ni; 98.70% for Co; and 98.8% for Cd.
The adsorption of heavy metals on the biochar produced from pomegranate peel at a
temperature of 450°C studied. Also, some sorption models were tested such as linear, Freundlich,
GK1 (new model), GK2, Quintelas, Fritz-Schluender II, Brouers and Fritz-Schluender III. The
results indicated that all tested models accurately fitted the sorption data where the determination
coefficient (R2) was more than 0.99. The sorption capacity was in the order of Pb > Co > Cd > Ni and average removal percentage was 98.44 % for Pb; 96.9 % for Ni; 98.18 % for Co and 97.46 %
for Cd %.
The fit for the tested sorption isotherm models calculated to select the most suitable
model express the sorption of heavy metals on biochar. The goodness of fit parameters were;
Sum square error (ERRSQ), Average relative error (ARE), nonlinear chi-square test (2),
Marquardt‘s percent standard deviation(MPSD), Sum of absolute errors (EABS) and Coefficient
of determination (R2). The Fritz-Schlueuder III model (five parameters model) proved to be more
accurate and stable for describing the sorption of heavy metals (Pb, Ni and Cd), but Brouers
model was accurate with Co sorption on PPBC 450oC.