| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4436223 | Applied Geochemistry | 2012 | 19 Pages |
This article discusses and analyzes data for geochemical monitoring of groundwater, collected in 1998–2008 at the international experimental radioecological study site (Chernobyl Pilot Site) located in the Red Forest radioactive waste dump site in the Chernobyl exclusion zone. Groundwater in the zone of influence of the studied waste trench no. 22T was characterized by a specific geochemistry. Along with a high content of 90Sr (of an order of n × 1000–n × 10,000 Bq/L) groundwater showed elevated concentrations of Ca, K, NO3-, SO42- and of some trace elements (in particular stable Sr), and had more acidic pH values compared to “background” aquifer conditions. The observed water quality changes are apparently related to degradation of organic matter (pine forest remnants, litter, humus containing topsoil layer) buried inside trench no. 22T, which have lead to acidification of groundwater and leaching of cations adsorbed on the exchange complex of soils buried inside the trench. Regime monitoring data for the project period of 1998–2008 shows a progressive decrease of concentrations of the leached ions accompanied by an increase of pH in the chemical plume emerging from the trench. This can be explained by a combined effect of a gradual decrease of the inventory, humification of the original organic matter inside the trench, and of nutrient element uptake by roots of the newly planted pine forest on top of the trench. The identified trends of evolution of geochemical regime favor attenuation of subsurface migration of 90Sr from Red Forest waste dumps due to an increase of the 90Sr distribution coefficients, and stabilization of plumes of contaminated groundwater.
► Groundwater geochemistry data set for a waste trench in Chernobyl zone is analyzed. ► Leaching losses from the trench are governed by degradation of buried organic matter. ► Geochemical impacts decrease in time due to humification of the organic matter. ► Additional factor controlling leaching losses is nutrient element uptake by vegetation. ► Evolution of geochemical regime favors attenuation of groundwater migration of 90Sr.
