UNDERSTANDING VARIATION IN PARTITION COEFFICIENT, Kd ...

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used in the look-up table to describe high thorium concentrations (Table 5.15). See Appendix I for a detailed account of the process used to select the K d values in Table 5.15. 5.9.6.2.1 Limits of K d Values with Respect to Organic Matter and Aluminum/Iron-Oxide Concentrations Of the 17 entries in the thorium K d data set (Appendix I), none of them had accompanying organic matter or aluminum- and iron-oxide mineral concentration data. It was anticipated that the presence of organic matter would decrease thorium K d values by forming thorium-organic matter complexes. These complexes would be less prone to adsorb to surface than the uncomplexed thorium species. Conversely, it was anticipated that the presence of aluminumand/or iron-oxides would increase thorium K d values by increasing the number of adsorption (surface complexation) sites. 5.9.6.2.2 Limits of K d Values with Respect to Dissolved Carbonate Concentrations Of the 17 entries in the thorium K d data set (Appendix I), none of them had accompanying carbonate concentration data. However, 5 entries had calcite (CaCO 3) mineral concentrations. It was anticipated that calcite concentrations could be used as an indirect measure, albeit poor measure, of the amount of dissolved carbonate in the aqueous phase. Calcite concentrations had a correlation coefficient (r) with thorium K d value of 0.76 (Appendix I). Although this is a relatively high correlation value, it is not significant at the 5 percent level of probability due to the small number of observations (5 observations). Furthermore, it was anticipated that the presence of dissolved carbonate would decrease thorium K d values due to formation of the weaker forming carbonate-thorium complexes. Table 5.15. Look-up table for thorium K d values (ml/g) based on pH and dissolved thorium concentrations. [Tabulated values pertain to systems consisting of low ionic strength (< 0.1 M), low humic material concentrations (
5.10 Tritium Geochemistry And K d Values 5.10.1 Overview: Important Aqueous- and Solid-Phase Parameters Controlling Retardation Tritium, a radioactive isotope of hydrogen with a half life (t ½) of 12.3 y, readily combines with oxygen to form water. Its behavior in aqueous systems is controlled by hydrologic processes and it migrates at essentially the same velocity as surface- and groundwaters. Aqueous speciation, precipitation, and sorption processes are not expected to affect the mobility of tritium in soil/water systems. 5.10.2 General Geochemistry Tritium ( 3 H) is a radioactive isotope of hydrogen. Three isotopes of hydrogen are known. These include the 2 stable isotopes 1 H (protium or H) and 2 H (deuterium or D), and the radioactive isotope 3 H (tritium or T). Tritium has a half life (t ½) of 12.3 y, and disintegrates into helium-3 ( 3 He) by emission of a weak beta ($ - ) particle (Rhodehamel et al., 1971). Tritium is formed by natural and man-made processes (Cotton and Wilkinson, 1980). Tritium is formed in the upper atmosphere mainly by the nuclear interaction of nitrogen with fast neutrons induced by cosmic ray reactions. The relative abundances of 1 H, 2 H, and 3 H in natural water are 99.984, 0.016, and 0-10 -15 percent, respectively (Freeze and Cherry, 1979). Tritium can also be created in nuclear reactors as a result of processes such as thermal neutron reactions with 6 Li. As an isotope of hydrogen, tritium in soil systems behaves like hydrogen and will exist in ionic, gaseous, and liquid forms (e.g., tritiated water, HTO). Ames and Rai (1978) discuss the geochemical behavior of tritium, and summarize field and laboratory studies of the mobility of tritium in soil systems. Because tritium readily combines with oxygen to form water, its behavior in aqueous systems is controlled by hydrologic processes. Because of these properties and its moderately long half life, tritium has been used as an environmental isotopic indicator to study hydrologic flow conditions. Rhodehamel et al. (1971) present an extensive bibliography (more than 1,200 references) and summarize the use of tritium in hydrologic studies through 1966. Tritium has been used to study recharge and pollution of groundwater reservoirs; permeability of aquifers; velocity, flow patterns, and stratification of surface- and groundwater bodies; dispersion and mixing processes in surface- and groundwaters; movement of soil moisture; chemisorption of soils and water-containing materials; biological uptake and release of water; and secondary recovery techniques for petroleum resources. IAEA (1979) published the proceedings from a 1978 conference dealing with the behavior of tritium in the environment. The conference was designed to provide information on the residence time and distribution of tritium in environmental systems and the incorporation of tritium into biological materials and its transfer along the food chain. 5.64
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United States Office of Air and Rad
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NOTICE The following two-volume rep
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This publication is the result of a
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TO COMMENT ON THIS GUIDE OR PROVIDE
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CONTENTS NOTICE ...................
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Concentrations Extractable Iron Con
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Appendix A - Acronyms and Abbreviat
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Figure E.1. Variation of K d for Cr
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Table 5.16. Uranium(VI) aqueous spe
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Table H.3. Simple and multiple regr
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1.0 Introduction The objective of t
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discussed. The geochemical modeling
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2.0 The K d Model The simplest and
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track many more parameters and some
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of interest. The retardation factor
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(e.g., soil). An increasing body of
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complexation constants for the cont
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the soil column. Additionally, the
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Element Table 5.2. Concentrations o
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5.2.3 Aqueous Speciation Cadmium fo
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5.2.4 Dissolution/Precipitation/Cop
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cadmium, indicating that cadmium an
Page 45 and 46: 5.2.6.2.2 Limits of K d Values with
Page 47 and 48: 5.3.4 Dissolution/Precipitation/Cop
Page 49 and 50: organic chelates (e.g., EDTA). Init
Page 53 and 54: (tarapacaite) in chromium sludge fr
Page 55 and 56: K d). Soils containing Mn oxides ox
Page 57 and 58: Table 5.7. Estimated range of Kd va
Page 59 and 60: most common valence state of lead e
Page 61 and 62: Table 5.8. Lead aqueous species inc
Page 63 and 64: Under reducing conditions, galena (
Page 65 and 66: C Adsorption of lead increases with
Page 69 and 70: (Choppin, 1983). Plutonium hydrolyt
Page 71 and 72: Table 5.10. Plutonium aqueous speci
Page 73 and 74: 5.6.5 Sorption/Desorption Plutonium
Page 75 and 76: content in the system. Additionally
Page 79 and 80: 5.7.4 Dissolution/Precipitation/Cop
Page 81 and 82: much greater concentrations. Thus,
Page 83 and 84: exchanged which they attributed to
Page 85 and 86: up tables was based in part on thei
Page 87 and 88: organic complexes likely predominat
Page 89 and 90: Thorium undergoes hydrolysis in aqu
Page 91 and 92: The distribution of thorium aqueous
Page 93 and 94: from about 10 -8.5 mol/l (0.0007 mg
Page 95: Based on the assumptions and limita
Page 99 and 100: uranium. Uranium(VI) species domina
Page 101 and 102: gives 0.1 to 10 µg/l as the range
Page 103 and 104: mineral in reducing ore zones (Fron
Page 105 and 106: Percent Distribution 100 80 60 40 2
Page 107 and 108: 5.11.6 Partition Coefficient, K d ,
Page 109 and 110: No attempt was made to statisticall
Page 111 and 112: Table 5.18. Selected chemical and t
Page 113 and 114: Another objective of this report is
Page 115 and 116: 6.0 REFERENCES Adriano, D. C. 1992.
Page 117 and 118: Bensen, D. W. 1960. Review of Soil
Page 119 and 120: Metals by Geomedia. Variables, Mech
Page 121 and 122: EPA (U.S. Environmental Protection
Page 123 and 124: Griffin, R. A., A. K. Au, and R. R.
Page 125 and 126: + Keeney-Kennicutt, W. L., and J. W
Page 127 and 128: Mattigod, S. V., A. L. Page, and I.
Page 129 and 130: Oscarson, D. W., and H. B. Hume. 19
Page 131 and 132: Relyea, J. F. and D. A. Brown. 1978
Page 133 and 134: Schultz, R. K., R. Overstreet, and
Page 135 and 136: Szalay, A. 1964. “Cation Exchange
Page 137 and 138: Yariv, S., and H. Cross. 1979. Geoc
Page 139 and 140: APPENDIX A Acronyms, Abbreviations,
Page 141 and 142: PC Personal computers operating und
Page 143 and 144: A.3.0 List of Symbols and Notation
Page 145 and 146: APPENDIX B Definitions
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Clay Content - particle size fracti
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Polynuclear Species - an aqueous sp
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C.1.0 Background Appendix C Partiti
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Cadmium K d Table C.2. Correlation
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C.3.0 Data Set for Soils Table C.4
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Cd K d (ml/g) Clay Cont. (wt%) pH C
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D.1.0 Background Appendix D Partiti
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A second data set (see Section D.4)
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Table D.3. Correlation coefficients
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By transposing the CEC and cesium K
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Table D.6. Cesium K d values measur
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eported in Table D.8 are described
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a 1 b 1 Range of Solution Cs Concen
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Figure D.4. Generalized cesium Freu
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Table D.10. Estimated range of K d
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D.3.0 K d Data Set for Soils and Pu
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Cesium Kd (ml/g) Clay (wt.% ) Mica
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Cesium K d (ml/g) Clay (wt%) Mica (
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Bruggenwert, M. G. M., and A. Kamph
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Shiao, S. Y., P. Rafferty, R. E. Me
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E.1.0 Background Appendix E Partiti
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chromium-reductive soils may stem f
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E.2.0 Approach The approach used to
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Table E.3. Estimated range of K d v
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Table E.4. Data from Rai et al. (19
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E.4.0 References Davis, J. A. and J
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APPENDIX F Partition Coefficients F
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(CEC) of the soils. Such an anomaly
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Table F.1. Summary of K d values fo
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Figure F.2. Variation of K d as a f
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F.4.0 References Abd-Elfattah, A.,
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APPENDIX G Partition Coefficients F
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A number of investigators have exam
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pH value, which is typical of the m
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These significant reductions in ads
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This is typically accomplished by t
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The scatterplots are typically disp
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Table G.2. Regression models for pl
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G.4.0 References Barney, G. S. 1984
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Nelson, D. M., R. P. Larson, and W.
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APPENDIX H Partition Coefficients F
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1.6 ml/g for a measurement made on
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Figure H.1. Relation between stront
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Figure H.2. Relation between stront
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H.2.4 Approach Figure H.4. Relation
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A second look-up table (Table H.5)
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Sr K d (ml/g) Clay Content (%) pH C
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Sr K d (ml/g) Clay Content (%) pH C
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Sr K d (ml/g) Clay Conten t (%) pH
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Konishi, M., K. Yamamoto, T. Yanagi
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APPENDIX I Partition Coefficients F
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descriptive statistics of the thori
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Figure I.1. Linear regression betwe
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The look-up table (Table I.5) for t
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Thorium K d (ml/g) pH Clay (wt.%) C
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Rai, D., A. R. Felmy, D. A. Moore,
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J.1.0 Background Appendix J Partiti
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J.2.2 Uranium K d Studies on Soils
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Washington. The studies included an
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and then decreases with increasing
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Kd (ml/g) 100,000 10,000 1,000 100
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papers. Warnecke et al. (1984) indi
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Anderson et al. (1982) summarize an
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McKinley and Scholtis (1993) compar
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In a similar comparison of sorption
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J.3.1 K d Values as a Function ff p
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discussed, and one would have to ma
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al., 1992; and others). These refer
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· Manskaya et al. (1956) studied a
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concentrations of humic acid, there
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pH U Kd (ml/g) Clay Cont. (wt.%) CE
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J.6.0 References Ames, L. L., J. E.
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Erikson, R. L., C. J. Hostetler, R.
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R. C. Ewing. Materials Research Soc
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Sheppard, M. I., and D. H. Thibault
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Yamamoto, T., E. Yunoki, M. Yamakaw
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