Abstract
The solubility of UO2HPO4 in normal seawater of 35‰ salinity was studied. The solubility of U(VI) phosphates in seawater increases nonlinearly with decreasing acidity (by two orders of magnitude per pH unit) due to formation of strong hydroxo, carbonate and, probably, phosphate complexes. At pH > 7.5, UO2HPO4 dissolves congruently. With decreasing pH to 6.9–7.2, UO2HPO4 is converted to UO2(H2PO4)2. The solubility of U(VI) phosphates in seawater considerably exceeds the natural uranium concentrations in seawater and pore solutions of the bottom sediments. Therefore, these compounds cannot form intrinsic minerals in the oceanic bottom sediments. The possibility of accumulation of U(VI) in sea phosphorites due to its chemisorption in the form of surface uranyl phosphate complexes is discussed.
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Original Russian Text © A.V. Savenko, 2006, published in Radiokhimiya, 2006, Vol. 48, No. 2, pp. 150–152.
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Savenko, A.V. Solubility of UO2HPO4 in seawater. Radiochemistry 48, 167–169 (2006). https://doi.org/10.1134/S1066362206020123
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DOI: https://doi.org/10.1134/S1066362206020123