97/00644 Metal behavior during fluidized bed thermal treatment of soil

Abstract

To study the impact of industrial pollution on the soil-to-plant uptake of fallout-radiocesium in a boreal forest ecosystem, four study sites were selected at distances of 7, 16, 21 and 28 km from the large copper–nickel smelter at Monchegorsk on the Kola Peninsula (Russia). At each site, soil and selected plant species were sampled from five plots and analysed separately for 137Cs and 40K. The data show that the root-uptake of 137Cs, as characterised by the median aggregated transfer-factor Tag, decreased significantly (P<0.05) with decreasing distance from the smelter for the plants Vaccinium myrtillus (from 0.023 to 0.007 m2 kg−1) and Empetrum nigrum (from 0.015 to 0.007 m2 kg−1), but increased for Deschampsia flexuosa (from 0.013 to 0.031 m2 kg−1). For Vaccinium vitis-idaea a significant trend for the Tag was not observed. The median 40K activity concentrations in these plants also decreased significantly (P<0.001) with decreasing distance from the smelter for Vaccinium myrtillus (from approx. 140 to 20 Bq kg−1 dry wt.), Empetrum nigrum (from approx. 90 to 40 Bq kg−1 dry wt.), and also for Deschampsia flexuosa (from approx. 270 to 40 Bq kg−1 dry wt.). For Vaccinium vitis-idaea such a continuous significant trend was not observed. The results for the Cu–Ni polluted soils thus show: (1) that the soil-to-plant transfer of radiocesium can be significantly modified; (2) that these modifications are quite specific; and (3) that modifications of the uptake of potassium do not always correspond to those of radiocesium.