scholarly journals Assessment of geochemical barriers at preservation of low-level radioactive waste storages

2019 ◽  
Vol 80 ◽  
pp. 03011
Author(s):  
Anatoly Boguslavsky ◽  
Olga Gaskova ◽  
Olga Naymushina
Keyword(s):  
Organic Matter ◽  
Radioactive Waste ◽  
Bottom Sediments ◽  
Geochemical Barriers ◽  
Organic Mineral ◽  
Modern Methods ◽  
Solid Phases ◽  
Deposition Processes ◽  
Key Sites ◽  
Low Level Radioactive Waste

The work considers geochemical aspects of the natural and man-made system for storing radioactive waste (RW) from one of the Siberian enterprises of the fuel and nuclear cycle. Careful geochemical testing of key sites of the system allows us to identify geochemical barriers that prevent the spread of uranium outside the sludge storage. In addition, experiments were conducted on the leaching of the sludge material in the laboratory using modern methods for determining the composition of solutions and solid phases, as well as experiments on uranium sorption on the main types of subsoil. Experimental and thermodynamic modeling of uranium deposition processes confirms that the system studied satisfactorily copes with the absorption of uranium taken out of the sludge storage due to dilution and sorption on rocks and bottom sediments. Particularly favorable are bottom sediments rich in organic matter, which bind uranium to organic-mineral complexes.

Geochemical barriers to elemental migration in sulfide-rich tailings: three case studies from Western Siberia

2012 ◽  
Vol 76 (7) ◽  
pp. 2693-2707 ◽  
Author(s):  
A. A. Bogush ◽  
O. G. Galkova ◽  
N. V. Ishuk
Keyword(s):  
Organic Matter ◽  
Western Siberia ◽  
Water Soluble ◽  
Processing Plant ◽  
Iron Oxyhydroxides ◽  
Geochemical Barriers ◽  
As Species ◽  
Organic Mineral ◽  
Zinc Processing ◽  
Sulfide Tailings

AbstractThis study describes geochemical barriers that have developed at three different localities in sulfiderich tailings in the Kemerovo region of Western Siberia, Russia. Iron oxyhydroxides, gypsum, malachite, chalcanthite, goslarite, bianchite, gunningite and copper and zinc chlorides crystallized in the sequence specified at an evaporative barrier around glassy slag produced by the Belovo zinc processing plant. A complex cemented barrier that has developed within the old Salair sulfide tailings contains two well defined layers: an upper layer containing Fe(III) minerals and gypsum as cements in which Pb, As, Mo, Ni and Co have been deposited; and (2) a lower calcite- and gypsum-bearing layer, in which phases containing Zn, Cd and Cu have been deposited. A complex organic-mineral barrier below the Ursk sulfide tailings consists of peaty organic matter, clay minerals and iron oxyhydroxides cemented by gypsum. Elements that have leached from the tailings are present in this barrier in a variety of different forms: Ca and Mn are present as water-soluble species; Cu, Fe and Zn are present as species produced by interaction with organic matter via ion-exchange, metal humate formation and cation bridging in organic-mineral complexes; Pb and As are co-precipitated with and/or adsorbed onto iron oxyhydroxides; gold has been deposited as minute particles of native metal. The mechanisms for the formation of the different geochemical barriers are discussed.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

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