Uptake and Release of Cesium‐137 by Five Plant Species as Influenced by Soil Amendments in Field Experiments

Abstract

Phytoextraction field experiments were conducted on soil contaminated with 0.39 to 8.7 Bq/g of 137Cs to determine the capacity of five plant species to accumulate 137Cs and the effects of three soil treatments on uptake. The plants tested were redroot pigweed (Amaranthus retroflexus L. var. aureus); a mixture of redroot pigweed and spreading pigweed (A. graecizans L.); purple amaranth (A. cruteus L.) x Powell's amaranth (A. powellii S. Watson), referred to here as the amaranth hybrid; Indian mustard [Brassica juncea (L.) Czern.]; and cabbage (Brassica oleracea L. var. capitata). For control plants, the concentration ratios (CR) of 137Cs were greatest for redroot pigweed and the amaranth hybrid, with average CR values of 1.0 +/- 0.24 and 0.95 +/- 0.14, respectively. The lowest value was for Indian mustard at 0.36 +/- 0.10. The soil treatments included (i) application of NH4NO3 solution to the soil after plants had matured, (ii) addition of composted manure to increase organic matter content of the soil, (iii) combination of the manure and ammonium solution treatments, and (iv) controls. The ammonium solution gave little overall increase in accumulation of 137Cs. The use of composted manure also had little influence, but the combination of the composted manure with application of ammonium solutions had a distinctly negative effect on plant uptake of 137Cs. On average the fraction of 137Cs taken up from the soil was reduced by 57.4 +/- 1.2% compared with controls. This was the result of release of competing ions, primarily Ca, from the manure and was observed across all five plant species tested. The application of ammonium solution took place in the last two weeks before harvest. The reduction of plant 137Cs content, by addition of the ammonium solution, as it interacted with the manure, indicates that substantial quantities 137Cs can be released from the shoots of plants as a result of sudden changes in soil solution chemistry.

Effects of various concentrations of uranium tailings on certain growth and biochemical parameters in sunflower

“…This new technology employs the use of higher plants capable of accumulating high levels of contamination in shoots. Following harvesting the shoot biomass can be disposed of a final repository after volume reduction (ashing) (Fuhramnn et al, 2004). The present investigation demonstrates that sunflower can tolerate uranium to a certain level and hence can be used to filter contaminated runoff and in hazardous radioactive waste sites.…”

Phytoremediation of Soil Trace Elements

“…Substantial species variation in Cs accumulation from soils has been demonstrated, but no special hyperaccumulator type was identified [244]. Researchers compared a number of species relative uptake of Cs and found that red root pigweed (Amaranthus retroflexus L.) accumulated much higher shoot Cs levels than other studied species [245,246]. Redroot pigweed bioaccumulated Cs from soils into shoots, while most other species accumulated Cs in roots.…”

Effect of waste mica on transfer factors of134Cs to spinach and lettuce

“…Such factors include soil type and properties (CEC, specific sorption properties, and the nature and amount of organic and mineral matter) (Manjaiah et al, 2003;Lembrechts, 1993;Monira et al, 2005), radionuclide interaction with the soil, level of potential sorptioncompetitive species in the soil solution, and type of crop. In addition to the radionuclide fraction available in the soil, the CEC of the soil, the solid-liquid distribution coefficient (K d ) and levels of competitive species (K + and NH 4 + ) for radiocesium can be used for prediction purposes (Absalom et al, 2001;Fuhrmann et al, 2003).…”