# Modeling and interpreting element ratios in water and sediments: A sensitivity analysis of post-Chernobyl Ru:Cs ratios

## Abstract

When elements are simultaneously added to lakes, experimentally or by accident, their ratios in the water phase and in bottom sediments can change with time due to differential partitioning between solution and suspended particles or sediments. A number of equations are developed to show the change of ratio with time in water and sediments assuming simultaneous pulse inputs followed by a range of combinations of loss processes form solution (i.e. hydraulic losses, sorption to particles followed by settling, and diffusion into the sediments). The pattern of events is discussed both for pulse events with specific limiting assumptions and for combined continuous and pulse inputs. The models show that elemental ratios in sediments are generally less sensitive indicators of differential partitioning that are elemental ratios in water. For lakes with long residence times, the long-term elemental ratio in the sediments does not differ from that in the initial spike to the water column, but for short residence times, it is directly dependent on the ratio of either partition or diffusion coefficients. The models are used to interpret Ru:Cs ratios measured in the water and sediments of Esthwaite Water subsequent to the pulse input of Chernobyl fallout. The ratios can be explainedmore »

- Authors:

- Institute of Freshwater Ecology, Windermere Lab., Cumbria (United Kingdom)
- Univ. of Lancaster (United Kingdom)
- Univ. of Manchester (United Kingdom)
- Institute of Terrestrial Ecology, Merlewood Lab., Cumbria (United Kingdom)

- Publication Date:

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 387344

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Limnology and Oceanography; Journal Volume: 40; Journal Issue: 7; Other Information: PBD: Nov 1995

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 54 ENVIRONMENTAL SCIENCES; 57 HEALTH AND SAFETY; LAKES; CONTAMINATION; SEDIMENTS; ISOTOPE RATIO; SENSITIVITY ANALYSIS; CESIUM; RUTHENIUM; REACTOR ACCIDENTS; ENVIRONMENTAL EFFECTS; CHERNOBYLSK-4 REACTOR

### Citation Formats

```
Hilton, J., Rigg, E., Davison, W., Hamilton-Taylor, J., Kelly, M., Livens, F.R., and Singleton, D.L.
```*Modeling and interpreting element ratios in water and sediments: A sensitivity analysis of post-Chernobyl Ru:Cs ratios*. United States: N. p., 1995.
Web. doi:10.4319/lo.1995.40.7.1302.

```
Hilton, J., Rigg, E., Davison, W., Hamilton-Taylor, J., Kelly, M., Livens, F.R., & Singleton, D.L.
```*Modeling and interpreting element ratios in water and sediments: A sensitivity analysis of post-Chernobyl Ru:Cs ratios*. United States. doi:10.4319/lo.1995.40.7.1302.

```
Hilton, J., Rigg, E., Davison, W., Hamilton-Taylor, J., Kelly, M., Livens, F.R., and Singleton, D.L. Wed .
"Modeling and interpreting element ratios in water and sediments: A sensitivity analysis of post-Chernobyl Ru:Cs ratios". United States.
doi:10.4319/lo.1995.40.7.1302.
```

```
@article{osti_387344,
```

title = {Modeling and interpreting element ratios in water and sediments: A sensitivity analysis of post-Chernobyl Ru:Cs ratios},

author = {Hilton, J. and Rigg, E. and Davison, W. and Hamilton-Taylor, J. and Kelly, M. and Livens, F.R. and Singleton, D.L.},

abstractNote = {When elements are simultaneously added to lakes, experimentally or by accident, their ratios in the water phase and in bottom sediments can change with time due to differential partitioning between solution and suspended particles or sediments. A number of equations are developed to show the change of ratio with time in water and sediments assuming simultaneous pulse inputs followed by a range of combinations of loss processes form solution (i.e. hydraulic losses, sorption to particles followed by settling, and diffusion into the sediments). The pattern of events is discussed both for pulse events with specific limiting assumptions and for combined continuous and pulse inputs. The models show that elemental ratios in sediments are generally less sensitive indicators of differential partitioning that are elemental ratios in water. For lakes with long residence times, the long-term elemental ratio in the sediments does not differ from that in the initial spike to the water column, but for short residence times, it is directly dependent on the ratio of either partition or diffusion coefficients. The models are used to interpret Ru:Cs ratios measured in the water and sediments of Esthwaite Water subsequent to the pulse input of Chernobyl fallout. The ratios can be explained by assuming nuclides were lost either by flusing and sorption or by flushing, sorption, and diffusion. The process combination of flushing and diffusion in incompatible with the observed constant ratios. 12 refs., 2 figs., 4 tabs.},

doi = {10.4319/lo.1995.40.7.1302},

journal = {Limnology and Oceanography},

number = 7,

volume = 40,

place = {United States},

year = {Wed Nov 01 00:00:00 EST 1995},

month = {Wed Nov 01 00:00:00 EST 1995}

}