The Impact of Biofilms upon Surfaces Relevant to an Intermediate Level Radioactive Waste Geological Disposal Facility under Simulated Near-Field Conditions

The ability of biofilms to form on a range of materials (cementious backfill (Nirex Reference Vault Backfill (NRVB)), graphite, and stainless steel) relevant to potential UK intermediate level radioactive waste (ILW) disposal concepts was investigated by exposing these surfaces to alkaliphilic flocs...

Full description

Saved in:
Bibliographic Details
Published in:Geosciences (Basel) 2017-07, Vol.7 (3), p.57
Main Authors: Charles, Christopher, Rout, Simon, Laws, Andrew, Jackson, Brian, Boxall, Sally, Humphreys, Paul
Format: Article
Language:English
Subjects:
alkaliphilic
Backfill
biofilm
Biofilms
Carbohydrates
carbonation
Deoxyribonucleic acid
DNA
Earth science
eDNA
engineered barrier
Environmental DNA
Extracellular
Graphite
intermediate level waste
isosaccharinic acid
Lipids
Microorganisms
NRVB
pH effects
Polysaccharides
Proteins
Radioactive waste disposal
Radioactive wastes
Stainless steel
Stainless steels
Waste disposal
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The ability of biofilms to form on a range of materials (cementious backfill (Nirex Reference Vault Backfill (NRVB)), graphite, and stainless steel) relevant to potential UK intermediate level radioactive waste (ILW) disposal concepts was investigated by exposing these surfaces to alkaliphilic flocs generated by mature biofilm communities. Flocs are aggregates of biofilm material that are able to act as a transport vector for the propagation of biofilms. In systems where biofilm formation was observed there was also a decrease in the sorption of isosaccharinic acids to the NRVB. The biofilms were composed of cells, extracellular DNA (eDNA), proteins, and lipids with a smaller polysaccharide fraction, which was biased towards mannopyranosyl linked carbohydrates. The same trend was seen with the graphite and stainless steel surfaces at these pH values, but in this case the biofilms associated with the stainless steel surfaces had a distinct eDNA basal layer that anchored the biofilm to the surface. At pH 13, no structured biofilm was observed, rather all the surfaces accumulated an indistinct organic layer composed of biofilm materials. This was particularly the case for the stainless steel coupons which accumulated relatively large quantities of eDNA. The results demonstrate that there is the potential for biofilm formation in an ILW-GDF provided an initiation source for the microbial biofilm is present. They also suggest that even when conditions are too harsh for biofilm formation, exposed surfaces may accumulate organic material such as eDNA.
ISSN:2076-3263
2076-3263
DOI:10.3390/geosciences7030057