| Abstract: |
SUMMARY AND CONCLUSIONThe aim of this work is to study the decontamination of some radioactively contaminated materials produced from radioisotopes applications. In this concern the experimental work is divided into two main parts, the first part deals with the study of the soThe second part deals with the study of the decontamination of surfaces from 137Cs and 85Sr. The purpose of this part is to provide the suitable methods and procedures for quantitive evaluation and degree of decontamination of surfaces under study. SimpleChapter one: IntroductionThis chapter includes the introduction that covering the following topics:• The nature of radioactive waste and its classifications (gaseous, liquid, solid wastes).• The characterization of waste and generated sources for many types of laboratories. The radioactive wastes are generated through the use of radionuclides in research, medical, industries, and other institutional activities.• Studying the type and nature of contamination and the factor that affecting on the decontamination process, such as chemical, physical and radiochemical nature of contaminants. The different methods and objectives of decontamination process are covered.• The nuclear, chemical and environmental characteristics of the investigated elements Cs+, Sr2+, Co2+ and Cr3+.Chapter two: Literature review and theoretical aspectsA literature survey covering three main topics is given. The first topic covers some aspects on the sorption study for the decontamination of aqueous solutions from radionuclides and also study the decontamination of solid surfaces by using different decoThe second topic deals with the study of the physico-chemical nature of sorption phenomena, chemical and electrostatic adsorption.The last part deals with the methods used for evaluation of the adsorption and the properties for bentonite clay and Dowex 50W-X8.Chapter three: ExperimentalThis chapter presented the different experimental procedures which were followed in the experimental work. In this thesis the work is divided into two main parts. The first part deals with the removal of the investigated elements from their aqueous solutiThe second part deals with the decontamination of surfaces from 137Cs and 85Sr. In these experiments two kinds of surfaces were chosen, the first samples is a metallic surface such as stainless steel, iron and the second is a non-metallic such as ceramicsChapter four: Results and discussionsThis chapter includes the obtained experimental results and their interpretation as well as comparison with published data:Part one: Sorption studies.• The Mineralogical analysis of the bentonite clay (natural material) shows that Montmorillonite is the most aboundant mineral and the sorption of bentonite to Sr2+, Co2+ and Cr3+ is affected by contact time, pH, competing ion concentration and metal ion • The metal sorbed percent of the investigated elements Sr2+, Co2+ and Cr3+ showed a gradual increase as pH increased in case of Co2+ and Sr2+ while in the case of Cr3+. The adsorption of Cr3+ decrease sharply till pH=5 by using Dowex and pH=6.5 in case o• The metal sorbed percent of the investigated elements on the Dowex 50W-X8 and bentonite clay was affected by low or moderate electrolyte concentration, which was attributed to the competition in ion exchange therefore, it is shown that the presence of M• Metal sorbed percent of the investigated elements showed a significant decrease with the increase of the metal ion concentration of these elements. The amount of cation sorbed per gram qe was found to increase as the carrier concentration increase. The • The obtained data show that both Dowex and bentonite clay can be considered as an efficient sorbent for the investigated metal cations of Sr2+ and Co2+ from their aqueous solutions and less efficient for Cr3+ at pH=4 and could be effectively used for thPart two: Decontamination of surfaces.• Decontamination of surfaces (Stainless steel, Iron, Ceramic, Glass, Wood) from 137Cs and 85Sr. In the decontamination experiments the surfaces chosen in the study is metallic and non-metallic surfaces. The results data from decontamination process of th
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