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۱Environmental Protection and treatment of Radio Active waste solutions in the Caspian sea using local clay minerals
نویسنده(ها): ،
اطلاعات انتشار: هفتمین همایش بین المللی سواحل، بنادر و سازه های دریایی، سال
تعداد صفحات: ۴
The aim of this work is to establish the optimum conditions for the removal of some radioactive elements from their waste solutions in the south west of the Caspian sea. In this respect an exploratory investigation is carried out using the clay minerals (kaolinite and vermiculite) to test the feasibility of its using for decontamination purposes and volume reduction. The different parameters affecting the sorption capacity of the radioactive elements of Cs–134, Co–60 and Eu–(152+154) by the investigated clay minerals have been studied. The uptake of the metal ion was determined for clay mineral–cation solution system as a function of contact time, pH, metal ion concentration and presence of some competing cations. Sorption data have been interpreted in terms of Freundlich equation. The presence of some organic complexing agents also affect the sorption process. The desorption of the investigated metal ions was also studied using different desorption solutions. The obtained data show that the clay mineral vermiculite can be considered as an efficient sorbent for metal cations from their aqueous solutions since the uptake efficiency is more than 90% for the three elements studied.<\div>

۲Environmental Geochemistry of Surficial sediments From the South–west of the Caspian–Sea
نویسنده(ها): ،
اطلاعات انتشار: هفتمین همایش بین المللی سواحل، بنادر و سازه های دریایی، سال
تعداد صفحات: ۴
The Caspian Sea is a Unique, evidently enclosed water body Shared between Iran and some neighboring Countries experiencing serious environmental problems.
The Caspian Sea receives river discharges which mostly Contain industrial and mining wastes. The Sediments provide a valuable record of environmental retrospective Changes. The heavy metal pollution of the environment of the Caspian Sea around Anzali area is gradually increasing due to urbanisation and industrial activities in the region. Therefore it is found to be interesting to investigate the pollution level of the Caspian sea around Anzali area using sediment Samples. In this Study surficial sediment samples, were analyzed quantitatively by neutron activation analysis (NAA) and activation autoradiography techniques.<\div>

۳Some Man–Made and Natural Radionuclide profiles in the Bottom Sediments of the Caspian Sea
نویسنده(ها): ،
اطلاعات انتشار: هفتمین همایش بین المللی سواحل، بنادر و سازه های دریایی، سال
تعداد صفحات: ۴
The bottom sediments collected in different parts of the Caspian Sea are analyzed for some natural and man–made radionuclides. The vertical profiles of radionuclides vary significantly for samples collected in different parts of the Caspian Sea. The 210Pb age–dating was performed for several sediment core samples together with determination of Plutonium isotope ratios that gave the indication of the origin of the radionuclides.
Bottom sediments are scavengers for some Uranium and Thorium chain radionuclides, man–made radionuclides and other pollutants. Historical deposition records could be build up using the radionuclide activities in the bottom sediments. The current knowledge of natural and artificial radionuclides in the vertical profiles of bottom sediments collected in different parts of the Caspian Sea is presented in this review. The atmospheric nuclear tests in 50–60ss and accident at the Chernobyl NPP (1986) are the main sources of man–made radionuclide contamination of the Caspian Sea. The possibility of some impact by the contemporary nuclear activities of European Countries is possible as well. The sediment cores were collected in the Anzali region.
The 210Pb age–dating and 238Pu\ 239, 240Pu, 241Pu\ 239, 240Pu ratios were used to determine the sedimentation rates and origin of the man–made radionuclides.<\div>
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