Abstract
79Se is among the most important long lived radionuclides
in spent nuclear fuel and selenite, SeO32-, is its
typical form in intermediate redox potential. The
sorption behaviour of selenite and the bacterial impact
on the selenite sorption in a 7-m-deep profile of a
nutrient-poor boreal bog was studied using batch sorption
experiments. The batch distribution coefficient (Kd)
values of selenite decreased as a function of sampling
depth and highest Kd values, 6600 L/kg dry weight (DW),
were observed in the surface moss and the lowest in the
bottom clay at 1700 L/kg DW. The overall maximum sorption
was observed at pH between 3 and 4 and the Kd values were
significantly higher in unsterilized compared to
sterilized samples. The removal of selenite from solution
by Pseudomonas sp., Burkholderia sp., Rhodococcus sp. and
Paenibacillus sp. strains isolated from the bog was
affected by incubation temperature and time. In addition,
the incubation of sterilized surface moss, subsurface
peat and gyttja samples with added bacteria effectively
removed selenite from the solution and on average 65% of
selenite was removed when Pseudomonas sp. or Burkholderia
sp. strains were used. Our results demonstrate the
important role of bacteria for the removal of selenite
from the solution phase in the bog environment, having a
high organic matter content and a low pH.
Original language | English |
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Pages (from-to) | 85-96 |
Journal | Journal of Environmental Radioactivity |
Volume | 147 |
DOIs | |
Publication status | Published - 2015 |
MoE publication type | A1 Journal article-refereed |
Keywords
- sorption
- biosorption
- selenite
- peat
- bacteria
- nuclear waste