Release of Aged Contaminants from weathered sediments: Effects of sorbate speciation on scaling of reactive transport

Other · Tue Aug 14 00:00:00 EDT 2012

OSTI ID:1186029

Chorover, Jon ^[1]; Perdrial, Nico ^[1]; Mueller, Karl ^[2]; Strepka, Caleb ^[2]; O'Day, Peggy ^[3]; Rivera, Nelson ^[3]; Um, Wooyong ^[4]; Chang, Hyun-Shik ^[4]; Steefel, Carl ^[5]; Thompson, Aaron ^[6]

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1. Univ. of Arizona, Tucson, AZ (United States)
2. Pennsylvania State Univ., University Park, PA (United States)
3. Univ. of California, Merced, CA (United States)
4. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
5. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
6. Univ. of Georgia, Athens, GA (United States)

Hanford sediments impacted by hyperalkaline high level radioactive waste have undergone incongruent silicate mineral weathering concurrent with contaminant uptake (Chorover et al., 2008). 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 thorough characterization of reaction products over a matrix of field-relevant gradients in contaminant concentration, P_CO2, 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. Below, we provide some detailed descriptions of our results from this three year study, recently completed following a one-year no cost extension.

• Research Organization: Univ. of California, Merced, CA (United States); Pennsylvania State Univ., University Park, PA (United States); Univ. of Arizona, Tucson, AZ (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• DOE Contract Number: FG02-08ER64614; FG02-08ER64615; FG02-08ER64616
• OSTI ID: 1186029
• Country of Publication: United States
• Language: English