Phytoextraction for clean-up of low-level uranium contaminated soil evaluated

Abstract

This study was executed to test if low-level U contaminated sandy soil from a nuclear fuel processing site could be phytoextracted in order to attain the required release limits. Two soils were tested: a control soil (317 Bq ²³⁸U kg^-1) and the same soil washed with bicarbonate (69 Bq ²³⁸U kg^-1). Ryegrass (Lolium perenne cv. Melvina) and Indian mustard (Brassica juncea cv. Vitasso) were used as test plants. The annual removal of the soil activity with the biomass was less than 0.1 %. The addition of citric acid (25 mmol kg^-1) one week before the harvest increased U uptake up to 500-fold and up to 3.5 % and 4.6 % of the soil activity could annually be removed with the biomass.