الفهرس 
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Abstract
The objective of this work is to study the extraction behavior of U022’
Co(11) , Eu(111) and Cr(1ll) by carbamoyl methyl phosphonate from weakly acidic
aqueous solutions Also comparing the extraction behavior of the compound with
the extraction behavior of other chelating agents like HTTA or HDEHP towards the
same elements.. In the present work extraction of elements was carded out from
nitrate , acetate and chloride media. The effect of composition, concentration and
nature of both the organic and aqueous phase on the extraction of the studied elements
was investigated Reactions describing the extraction process was were proposed
their reaction constants and thermodynamic functions were calculated :The thesis is
composed from three chapters. The first contains details on some solvent extraction as
regards types of compounds used, mechanisms and types of compounds used in each
type . It also includes information about synergistic solvent extraction with their
possible mechanisms. Concise summary on the chemistry of the studied elements
and a literature survey on the separation of each one by different separation
techniques are also contained in this chapter.
The second chapter includes the chemicals used in the present study and the
preparation of radioisotopes handled . It also includes the instruments used as will as
the methodology of experimentation that been followed for the extraction studies
Chapter three includes the results obtained, their analysis and discussion, it is
divided into four separate parts.
Part one comprise the results obtained on the use of solution of the
phosplionate compound DHDECMP in pyclohexane for extracting U(VI) from
aqueous nitrate solutions .The parameters studied are the effect of pH of the aqueous
phase, effect of DHDECMP concentration in the organic phase . Based on the
knowledge of the species of UO22~ in the nitrate medium under the studied conditions
the extracted complex was found to have the form U02(DHDECMP)2 with log k of
the extraction reaction
0.54 ± 0.052 . In studying the effect of adding TBP or TOPO to DHDECMP for
extracting U(V1) . The results obtained shows extraction enhancement synergically
with either TBP or TOPO where the latter compound give higher enhancement that
the former This higher enhancement in extraction with TOPO is to be attributed to
higher basicity or higher electron donation of TOPO compared to TBP. The data
obtained from the experiments for studying the effect ofTBP or TOPO concentration
on extraction of U(VI) with the phosphonate shows the extracted species have the
form [U02(DHDECMP)2 .5) where S refers to TBP or TOPO with log k of the
reaction leading to the formation of this species is calculated to be 4.025 ± 0.05 and
5.14±0.09 for TBP and TOPO respectively. Results on the effect of temperature on
the extraction of U(VI) DHDECMP alone or the synergistic extraction reaction
shows that both reactions are endothermic. The thermodynamic parameters for the