Sorption of Manganese, Uranium, and Radium by Highly Weathered Soils
Large concentrations of Mn, 238U, and 226Ra are present in U mine waste waters in comparison with those in surrounding natural waters. Excess mine waste water is being disposed by irrigation of bushland near Ranger Uranium Mine, Northern Territory, Australia. We report the sorption properties of highly weathered and sandy soils (Utric Acruustox, Grossameric Kandiustalf, and Typic Fragiumbrept), near the mine for Mn, U, and 226Ra as determined by batch sorption experiments, and competitive sorption between U and Mn. Manganese sorption was small in comparison with loads expected to be applied to the soils, and Mn was expected to be mobile within the soils. In contrast with Mn, U sorption by the soils was very much greater than the amount that may be applied. Simultaneous additions of U and Mn reduced sorption of both, but the effect of U on Mn sorption was far greater than that of Mn on U. Uranium also caused the displacement of Mn from the soil in the absence of added Mn. The U additions favored the mobility of Mn. Radium−226 at trace levels was strongly sorbed by the soil and <1% of the sorbed 226Ra was displaced during the desorption step. Uranium and 226Ra applied as mine waste water will be retained in surface soil, but Mn was expected to be relatively mobile, particularly in the sandiest soils and when applied in waters that also contain U.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .