Identification and effects of anthropogenic emissions of U and Th on the composition of sediments in a river/estuarine system in Southern Spain

U and Th speciation in river sediments

“…In the residual fractions F5 and F6 the Th/U mass ratio for all samples, except sample S02, has values above unity and close to the typical value for near surface rocks of 3.5 [8]. Toe exception of both residual fractions of sample S02 confirms the U enrichment relative to Th typical of the phos phate mineral utilised in the fertilizer production [7].…”

“…Thus, U is incorporated into the local sediment predominantly by adsorption from the liquid phase. A different chemical asso ciation in the wastes must be responsible for the 'anomalous' U distribution observed in this sta tion and related to the discharges from the phos phogypsum storage area [2,7].…”

On seasonal variations of radiocesium speciation in the surface sediments of Lake Juodis, Lithuania

“…Speciation of radiocesium and other trace metals in soils and sediments is widely used to estimate their behavior, mobility and bioavailability as well as their sources (Alberts et al, 1989;Martinez-Aguirre et al, 1994;Cundy and Croudace, 1995;Askbrant et al, 1996;Bunzl et al, 1998;Forsberg et al, 2001;Hlavay et al, 2004;Korfali and Davies, 2005;Deryagin et al, 2006). Physico-chemical form separation techniques are mainly based on a sequential chemical extraction method of Tessier et al (1979).…”

Enhanced U and Th concentrations in soils from a wet Marshland washed by contaminated riverwaters

“…Large enhancements of natural radionuclides in solution, suspended matter and bottom sediments were previously found at the Odiel and Tinto river basins (Martínez- Aguirre et al, 1994aAguirre et al, , 1994bAguirre et al, , 1994c. This enhancement was attributed to the wastes released by industries which process phosphate rock for phosphoric acid production.…”