Ayora, Carlos

Carrera, Jesús

De Pourcq,  K.

García-Gutiérrez, M.

Mingarro, M.

Missana,  T.

English

Missana, T.

Mingarro, Mario

Digital.CSIC

European Mineralogical ConferenceVol. 1, EMC2012-282, 2012European Mineralogical Conference 2012© Author(s) 2012Design of a Permeable Reactive Barrier to retain Cs-137C. Ayora (1), K. De Pourcq (1), J. Carrera (1), M. García-Gutiérrez (2), T. Missana (2), and M. Mingarro (2)(1) IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (cayora1@gmail.com), (2) CIEMAT, Avda. Complutense s/n, 28040MadridA Permeable Reactive Barrier has been designed to treat Cs-137 polluted groundwater. In order to check bothreactivity and permeability, laboratory batch and column tests combined with reactive transport modeling havebeen performed. The trapping mechanism is based on the sorption of cesium on illite-containing clays. Batchexperiments were conducted to obtain the partition coefficients (Kd) of different clay samples in solutions withdifferent potassium concentration. The results were modeled with a cation-exchange model.The permeability of the reactive material is provided by the dispersion of the clay on a matrix of wooden shavings.Constant head tests allowed obtaining permeability values. The mixture of wooden shavings and clay (2:1 byweight) is a material that has a hydraulic conductivity (10-4 m/s) high enough to ensure an adequate hydraulicperformance for an eventual PRB excavated in many aquifers.Several column experiments with different flow rates were conducted to confirm the Cs retention under differentconditions. A blind 1D reactive transport model based on the cation-exchange model was able to predict reasonablywell the results of column experiments.The reactive transport model, validated with the column experiments, was used to investigate the performanceand duration of 1m thick barrier under different scenarios (flow, clay proportion, Cs-137 and K concentration).As expected, the sensitivity tests proved that the retention capacity of dissolved Cs-137 in groundwater dependslinearly on the amount of clay used in the filling material. As well, the operation time increases linearly whendecreasing the flow rate. Finally, the concentration of potassium in inflow water has a remarkable and non-linearinfluence in the retention of Cs-137. Very high concentrations of potassium are the greatest threat and can lead tothe infeasibility of the permeable reactive barrier. Due to the Cs-K competition, the barrier is comparatively moreefficient to treat high concentrations of Cs-137.

Design of a permeable reactive barrier to retain Cs-137.

https://digital.csic.es/bitstream/10261/213548/1/441206.pdf

Design of a permeable reactive barrier to retain Cs-137.

Abstract

Similar works

Full text

Available Versions

Digital.CSIC