干旱区生态环境知识资源中心(Arid): Physico-chemical conditions controlling the radionuclides mobilisation in various granitic environments

Arid

DOI	10.1080/03067319.2020.1729758
	Physico-chemical conditions controlling the radionuclides mobilisation in various granitic environments
	El Mezayen, Ahmed M.1; Ibrahim, Eman M.2; El-Feky, Mohamed G.2; Omar, Sayed M.2; El-Shabasy, Ahmed M.3; Taalab, Sherif A.1
通讯作者	Taalab, Sherif A.
来源期刊	INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
ISSN	0306-7319
EISSN	1029-0397
出版年	2020-03
英文摘要	Nine samples were chemically characterized and radiometrically analyzed for determination of U-234, U-238, U-235, Th-230, Th-232, Ra-226 and K-40 by gamma-ray spectrometer Hyper Purity Germanium (HPGe detector). U-238 activity concentrations reach up to 79.78 Bq Kg(-1)in the altered granites, 1714.11 and 2223.48 Bq Kg(-1)in the episyenite and pegmatite. Average U-234 activity concentrations in the altered granite is 59.26 Bq Kg(-1), between 175.88-543.47 Bq Kg(-1)and 48.19-1102.88 Bq Kg(-1)in the episyenite and pegmatite, respectively. Th-232 activity concentrations vary between 14.16-1024.8 Bq Kg(-1)in the episyenite, 11.46-240.27 in the pegmatite and reach up to 201.45 Bq Kg(-1)in the altered granites. K-40 activity concentrations range between 4.42-9.15, 2.76-7.34 and 2.68-9.94 Bq Kg(-1)in the altered granite, episyenite and pegmatite, respectively. U-235 activity concentration ranges between 3.74-2.56, 12.45-78.86 and 0.58-102.34 Bq Kg(-1) in the altered granite, episyenite and pegmatite, respectively. The studied altered granite, episyenite and pegmatite samples have relatively higher values than recorded in the international standards with the exception of potassium which has lesser amounts. It is demonstrated that pH changes, oxidation-reduction conditions, mineralogical constituents, in addition to alteration processes in these variable granitic environments were the main factors controlling uranium mobilization according to valid processes. The difference in alteration processes and La/Y ratio clarified the presence of more than one event of uranium accumulation and/or leaching in these rocks as confirmed by the presence of uranium accumulation and uranium vacant occurrences. Also, the isotopic ratios of uranium as U-238/U-235,U-234/U-235, U-234/ U-238, Ra-226/ U-238,Ra-226/ Th-230, Pb-210/ Ra-226, Th-230/ U-238, Th-230/ U-234 with major, trace and rare earth elements were also affected by physico-chemical conditions changes. The present study shows that the samples of episyenite and pegmatite have been affected by leaching-accumulation events in the period from (1 x 10(5) to >2 x 10(5)years).
英文关键词	Uranium physico-chemical conditions pegmatites chemical index of alteration (CIA) Kab Amiri area Egypt
类型	Article ; Early Access
语种	英语
国家	Egypt
收录类别	SCI-E
WOS记录号	WOS:000518416500001
WOS关键词	RARE-EARTH-ELEMENTS ; EASTERN DESERT ; GEOCHEMISTRY ; URANIUM ; RADIOACTIVITY ; FRACTIONATION ; DISEQUILIBRIA ; DEPOSIT ; WATER ; AREA
WOS类目	Chemistry, Analytical ; Environmental Sciences
WOS研究方向	Chemistry ; Environmental Sciences & Ecology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/314761
作者单位	1.Al Azhar Univ, Dept Geol, Cairo, Egypt; 2.Nucl Mat Author, Geochem Explorat Dept, Cairo, Egypt; 3.ENRRA, Radiat Protect Dept, Cairo, Egypt
推荐引用方式 GB/T 7714	El Mezayen, Ahmed M.,Ibrahim, Eman M.,El-Feky, Mohamed G.,et al. Physico-chemical conditions controlling the radionuclides mobilisation in various granitic environments[J],2020.
APA	El Mezayen, Ahmed M.,Ibrahim, Eman M.,El-Feky, Mohamed G.,Omar, Sayed M.,El-Shabasy, Ahmed M.,&Taalab, Sherif A..(2020).Physico-chemical conditions controlling the radionuclides mobilisation in various granitic environments.INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY.
MLA	El Mezayen, Ahmed M.,et al."Physico-chemical conditions controlling the radionuclides mobilisation in various granitic environments".INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY (2020).