Final Project Report: Release of aged contaminants from weathered sediments: Effects of sorbate speciation on scaling of reactive transport

Jon Chorover, University of Arizona ; Peggy O'????????????????Day, University of California, Merced ; Karl Mueller, Penn State University ; Wooyong Um, Pacific Northwest National Laboratory ; Carl Steefel, Lawrence Berkeley National Laboratory

关键词: Hanford;    sediment weathering;    caustic waste;    strontium;    cesium;    speciation;    reactive transport;   

DOI  :  10.2172/1052233
RP-ID  :  FINAL REPORT
PID  :  OSTI ID: 1052233

学科分类：环境科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

Hanford sediments impacted by hyperalkaline high level radioactive waste have undergone incongruent silicate mineral weathering concurrent with contaminant uptake. In this project, we studied the impact of background pore water (BPW) on strontium, cesium and iodine desorption and transport in Hanford sediments that were experimentally weathered by contact with simulated hyperalkaline tank waste leachate (STWL) solutions. Using those lab-weathered Hanford sediments (HS) and model precipitates formed during nucleation from homogeneous STWL solutions (HN), we (i) provided detailed characterization of reaction products over a matrix of field-relevant gradients in contaminant concentration, PCO2, and reaction time; (ii) improved molecular-scale understanding of how sorbate speciation controls contaminant desorption from weathered sediments upon removal of caustic sources; and (iii) developed a mechanistic, predictive model of meso- to field-scale contaminant reactive transport under these conditions.