Supporting Information For Quantifying Differences in the Impact of ...
Supporting Information For Quantifying Differences in the Impact of Variable Chemistry on Equilibrium Uranium(VI) Adsorption Properties of Aquifer Sediments
Deborah L. Stoliker1*, Douglas B. Kent1, and John M. Zachara2 1
U. S. Geological Survey, 345 Middlefield Rd. MS 496, Menlo Park, CA, 94025, USA 2
*
Pacific Northwest National Laboratory, Richland, WA, USA
Corresponding author. Deborah Stoliker, U. S. Geological Survey, 345 Middlefield Rd., MS 496, Menlo Park, CA, 94025, USA, phone: 650-329-4529, fax: 650-329-4545, email: [email protected] For submission to Environmental Science and Technology August 2011
Pages: 16 Figures: 4 Tables: 5 S1
Iron Extraction Results. The acidic oxalate extraction, while designed to attack poorly crystalline iron oxides, can attack more crystalline minerals such as magnetite and lepidocrocite as well as biotite, chlorite, and ilmenite.1,2,3 The presence of chlorite had been confirmed in Hanford 300-Area sediments by fluorescence studies and attraction of the sediment grains to a magnet strongly suggests the presence of magnetite.4 This extraction, therefore, likely overestimates the amount of amorphous iron. While hydroxylamine hydrochloride extractions may access amorphous iron phases without attacking magnetite, the acidic nature of the extractant is still problematic for clays and may attack the same iron substituted alumino-silicates affected by ammonium oxalate. The circum-neutral CBD extractions, designed to attack amorphous and crystalline iron oxides, dissolve minimal amounts of magnetite and ilmenite and contributions from leaching of alumino-silicates are smaller.5 The effectiveness of CBD extractions is confounded by particle size with incomplete complexation of iron within larger mineral grains possibly underestimating the crystalline and amorphous iron concentrations.6 Grinding the SOUO2CO3- + H+
25.34
0.07
1.17
26.21
0.08
5.04
7
>SOH + UO22+ + CO32= >SOUO2HCO3
33.44
0.08
3.17
34.68
0.11
6.34
8
>SOH + UO22+ + H2O = >SOUO2OH + 2H+
29.23
0.08
2.87
38.78
0.13
6.64
9
>SOH + UO22+ = >SOUO2+ + H+
37.32
0.10
5.56
30.34
0.11
6.22
a
Fines refer to the
Deborah L. Stoliker1*, Douglas B. Kent1, and John M. Zachara2 1
U. S. Geological Survey, 345 Middlefield Rd. MS 496, Menlo Park, CA, 94025, USA 2
*
Pacific Northwest National Laboratory, Richland, WA, USA
Corresponding author. Deborah Stoliker, U. S. Geological Survey, 345 Middlefield Rd., MS 496, Menlo Park, CA, 94025, USA, phone: 650-329-4529, fax: 650-329-4545, email: [email protected] For submission to Environmental Science and Technology August 2011
Pages: 16 Figures: 4 Tables: 5 S1
Iron Extraction Results. The acidic oxalate extraction, while designed to attack poorly crystalline iron oxides, can attack more crystalline minerals such as magnetite and lepidocrocite as well as biotite, chlorite, and ilmenite.1,2,3 The presence of chlorite had been confirmed in Hanford 300-Area sediments by fluorescence studies and attraction of the sediment grains to a magnet strongly suggests the presence of magnetite.4 This extraction, therefore, likely overestimates the amount of amorphous iron. While hydroxylamine hydrochloride extractions may access amorphous iron phases without attacking magnetite, the acidic nature of the extractant is still problematic for clays and may attack the same iron substituted alumino-silicates affected by ammonium oxalate. The circum-neutral CBD extractions, designed to attack amorphous and crystalline iron oxides, dissolve minimal amounts of magnetite and ilmenite and contributions from leaching of alumino-silicates are smaller.5 The effectiveness of CBD extractions is confounded by particle size with incomplete complexation of iron within larger mineral grains possibly underestimating the crystalline and amorphous iron concentrations.6 Grinding the SOUO2CO3- + H+
25.34
0.07
1.17
26.21
0.08
5.04
7
>SOH + UO22+ + CO32= >SOUO2HCO3
33.44
0.08
3.17
34.68
0.11
6.34
8
>SOH + UO22+ + H2O = >SOUO2OH + 2H+
29.23
0.08
2.87
38.78
0.13
6.64
9
>SOH + UO22+ = >SOUO2+ + H+
37.32
0.10
5.56
30.34
0.11
6.22
a
Fines refer to the
