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

J Environ Radioact. 2004;72(1-2):41-5. doi: 10.1016/S0265-931X(03)00184-X.

Abstract

Spills in the nuclear fuel cycle have led to soil contamination with uranium. In case of small contamination just above release levels, low-cost yet sufficiently efficient remedial measures are recommended. 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 soil activity by the biomass was less than 0.1%. The addition of citric acid (25 mmol kg(-1)) 1 week before the harvest increased U uptake up to 500-fold. With a ryegrass and mustard yield of 15,000 and 10,000 kg ha(-1), respectively, up to 3.5% and 4.6% of the soil activity could be removed annually by the biomass. With a desired activity reduction level of 1.5 and 5 for the bicarbonate-washed and control soil, respectively, it would take 10-50 years to attain the release limit. However, citric acid addition resulted in a decreased dry weight production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biodegradation, Environmental
  • Biomass
  • Brassica / chemistry*
  • Brassica / growth & development
  • Lolium / chemistry*
  • Lolium / growth & development
  • Power Plants
  • Radioactive Hazard Release*
  • Silicon Dioxide
  • Soil Pollutants, Radioactive / isolation & purification*
  • Uranium / isolation & purification*

Substances

  • Soil Pollutants, Radioactive
  • Uranium
  • Silicon Dioxide