Chapter 1
17
Fig. 1.4 Structure of ettringite. (a) Perpendicular to c-axis shown columns and channels, (b) projection of ettringite structure, (c) expended the dash line regions in (a) and (b) [58, 73].
Amalia et. al. reported that ettringite will be decomposed at lower than 50 °C and could not be as hazardous elements and radionuclides host phase, especially for 79Se [75]. However, calcination is a concern for the treating the spent absorbents which have incorporated hazardous elements or radionuclides, such as hot isostatic pressing (HIP) or incorporated in the ceramics, prior to landfilling [78-80]. Thus, the calcination behavior of hazardous elements and radionuclides bearing ettringite should be discussed and investigated for treating hazardous wastes, especially for nuclear wastes treatment.
Chapter 1
18
human beings, excess uptaking of these elements will also cause some serious diseases. In addition, selenium and iodine radioactive isotopes could be other risks for ecosystems or living organisms. Considering the rarity of 79Se and 129I in the nature, it is likely that actual human exposures will be extremely low. However, the long-lived nature of 79Se and 129I and their potential for transport in alkaline geosphere conditions dictate that these radionuclides is of current interest in safety assessments of geological radioactive waste repositories.
The confinement of radionuclides or hazardous elements is an important issue for preventing environmental contamination and helping to maintain safe ecosystems for living organisms.
As one of the major compound forms during cement hydration, ettringite is supposed to play an important role in toxic ions immobilization process in Portland cement because Portland cement is generally applied as a matrix for the immobilization and storage low and intermediate level nuclear wastes and other hazardous wastes. Incorporating of radioactive or toxic ions in ettringite has been investigated by numbers of researchers. However, some aspects are still not completely understood.
Therefore, this study explored the mechanism of SeO32–, SeO42–, I–, and IO3– coprecipitation with ettringite and the properties of guest anions doped ettringite. Through the ettringite structure, the immobilization of SeO32–, SeO42–, I–, and IO3– was elaborated to interpret.
Furthermore, the selenate hydrocalumite was proved to be the intermediate to form selenate ettringite. The stability of ettringite was also investigated for evaluation of its ability to
Chapter 1
19
accommodate radionuclides. However, ettringite exhibits lower stability when this mineral encounters some higher electronegative anions. Because calcination is a concern for the treating the spent absorbents which have incorporated hazardous elements or radionuclides, the calcination behavior of hazardous elements bearing ettringite was discussed and investigated. Finally, some industrial by-products were applied to synthesize glassy-ceramics for incorporating selenate bearing ettringite.
The main research aspects of this thesis are:
(1) The immobilization mechanism of Se oxoanions was evaluated through structural insight into ettringite. SeO32– and SeO42– proved to exhibit different immobilization mechanism. The details of the immobilization mechanism were interpreted via water chemistry, XRD, EXAFS, and FTIR results.
(2) The effect of SO42– on SeO42– immobilization was investigated. When SO42– and SeO42–
coexisted in solution, both oxoanions were immediately coprecipitated with ettringite after adding a Ca source. Without SO42–, SeO42–-substituted hydrocalumite formed as an intermediate which was shown to affect the formation of SeO42––substituted ettringite.
(3) In order to figure out the immobilization performance mechanism of I– and IO3–
via ettringite, various anions with different ionic radius and valences were selected to co-precipitate with ettringite. According to the different anions' properties and the structure of ettringite, the immobilization mechanism of various anions via ettringite is finally proved to
Chapter 1
20
relate to the subjected anions' hydration ability and ionic radius.
(4) The structural transformation of ettringite has been evidenced based on the results of X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), and extended X-ray adsorption fine structure (EXAFS). The structural transformation is caused by the electrostatic repulsion between sulfate and selenate. However, the atomic arrangement of columnar parts of selenate ettringite is still maintained.
(5) The thermal stability of SeO42– bearing ettringite was investigated. The reduction of SeO42− to SeO32− and the changes of coordination of Se oxoanions were observed under high-temperature calcination. Furthermore, calcination of SeO42– bearing ettringite at 800 °C much improved the stability of selenium.
(6) Selenate-doped ettringite was mixed with granulated blast furnace slag (GBFS) and silica fume (SF) and then calcined at various temperatures to produce glass-ceramics. Above 800 °C, the amorphous mixture was converted to glass-ceramics. The synthesized ceramics exhibited excellent behavior for immobilization of selenate. Stabilization mechanism is revealed by X-ray photoelectron spectroscopy (XPS).
References
[1] N.N. Greenwood, and A. Earnshaw, Chemistry of the Elements. Elsevier (2012).
[2] P. Patnaik, Handbook of inorganic chemicals (Vol. 529). New York: McGraw-Hill (2003).
Chapter 1
21
[3] B.J. Alloway, Sources of heavy metals and metalloids in soils. In Heavy metals in soils (pp. 11-50). Springer, Dordrecht (2013).
[4] P. Škácha, J. Sejkora, and J. Plášil, Selenide Mineralization in the Příbram Uranium and Base-Metal District (Czech Republic). Minerals, 7 (2017) 91.
[5] D.F. Davidson, Selenium in some epithermal deposits of antimony, mercury and silver and gold (No. 1112). US Government Printing Office.
[6] G. Jörg, R. Bühnemann, S. Holla, N. Kivelc, K. Kossertd, S.V. Winckelb, and C. L.
Gostomskia, Preparation of radiochemically pure 79Se and highly precise determination of its half-life. Appl. Radiat. Isotopes. 68 (2010) 2339–2351.
[7] K.J.R. Rosman, and P.D.P. Taylor, Isotopic compositions of the elements 1997 (Technical Report). Pure and Applied Chemistry, 70 (1998) 217-235.
[8] V.R. Preedy, (Ed.). Selenium: Chemistry, Analysis, Function and Effects. Royal Society of Chemistry (2015).
[9] G. Audi, O. Bersillon, J. Blachot, and A.H. Wapstra, The NUBASE evaluation of nuclear and decay properties. Nuclear Physics A, 729 (2003) 3-128.
[10] D.A. Atwood, (Ed.). Radionuclides in the Environment. John Wiley & Sons (2013).
[11] J. E. Fergusson, The heavy elements chemistry, environmental impact and health effects, Pergamon Press. Inc. NY (1990).
[12] D.F. Shriver, P. Atkins, C.H. Langford, Inorganic Chemistry, Second ed., Freeman, New York, 2010.
[13] D.L. Sparks, Environmental Soil Chemistry, Second ed., Academic Press, Amsterdam, 2003.
[14] D.G. Brookins, Eh-pH diagrams for geochemistry. Springer Science & Business Media (2012).
[15] U.S. Environmental Protection Agency, Selenium Compounds and Hazard Summary-revised, US Environmental Protection Agency, Washington, DC, January 2000, http://www.epa.gov/ttn/atw/hlthef/selenium.html (accessed 16.02.12).
Chapter 1
22
[16] World Health organization, Selenium in drink water: Background document for development of WHO Guidelines for Drinking-water Quality, 2014.
http://www.who.int/water_sanitation_health/dwq/chemicals/selenium/en/(accessed 16.02.12).
[17] C.M. Bethke, and S. Yeakel, The geochemist’s workbench®, Release 10.0. Latest version available at The Geochemist's Workbench(2015).
[18] D. R. Lide, CRC handbook of chemistry and physics. Boca Raton, FL, 2000 (2012).
[19] R. Fuge, and C.C. Johnson, The geochemistry of iodine—a review. Environmental geochemistry and health, 8 (1986) 31-54.
[20] WHO (World Health Organization) Iodine Deficiency Disorders, 2009, http://www.
who. int/ nutrition /topics/ idd/en/ (accessed February 12, 2009).
[21] M. Zimmermann, and F. Delange, Iodine supplementation of pregnant women in Europe: a review and recommendations. European journal of clinical nutrition, 58 (2004) 979.
[22] B. Clement, L. Cantrel, G. Ducros, F. Funke, L. Herranz, A. Rydl, G. Weber, and C.
Wren, State of the art report on iodine chemistry (NEA-CSNI-R--2007-01). Nuclear Energy Agency of the OECD (NEA) (Feb 2007).
[23] J.E. Moran, S. Oktay, P.H. Santschi, and D.R. Schink, Atmospheric dispersal of
129Iodine from nuclear fuel reprocessing facilities. Environ. Sci. Technol., 33 (1999) 2536-2542.
[24] B.J. Riley, J.D. Vienna, D.M. Strachan, J.S. McCloy, and J.L. Jerden, Materials and processes for the effective capture and immobilization of radioiodine: A review. J.
Nucl. Mater., 470 (2016) 307-326.
[25] D.A. McKeown, I.S. Muller, and I.L. Pegg, Iodine valence and local environments in borosilicate waste glasses using X-ray absorption spectroscopy. J. Nucl.
Mater., 456 (2015) 182-191.
[26] G.G. Goles, and E. Anders, Abundances of iodine tellurium and uranium in meteorites. Geochimica et Cosmochimica Acta, 26 (1962), 723-737.
Chapter 1
23
[27] E.M., Chapman, B.N., Skanse, and R.D. Evans, Treatment of Hyperthyroidism with Radioactive Iodine: (I130, 12-Hour Half-Life and I131, 8-Day Half-Life). Radiology, 51 (1948) 558-563.
[28] United Nations. Scientific Committee on the Effects of Atomic Radiation.
(2000). Sources and effects of ionizing radiation: sources (Vol. 1). United Nations Publications.
[29] Y. Morino, T. Ohara, and M. Nishizawa, Atmospheric behavior, deposition, and budget of radioactive materials from the Fukushima Daiichi nuclear power plant in March 2011. Geophysical research letters, 38 (2011).
[30] N. Yoshida, and Y. Takahashi, Land-surface contamination by radionuclides from the Fukushima Daiichi Nuclear Power Plant accident. Elements, 8 (2012) 201-206.
[31] S.C.H.A.E.F.F.E.R., O.A., Katcoff, Schaeffer, and J.M. Hastings, Half-life of I129 and the age of the elements. Physical Review, 82 (1951) 688.
[32] R.C. Bolles, and N.E. Ballou, Calculated Activities and Abundances of U235 Fission Products. Nuclear Science and Engineering, 5 (1959) 156-185.
[33] Q.H. Hu, J.Q. Weng, and J.S. Wang, Sources of anthropogenic radionuclides in the environment: a review. Journal of environmental radioactivity, 101 (2010). 426-437.
[34] J.E. Moran, S. Oktay, P.H. Santschi, and D.R. Schink, Atmospheric dispersal of 129Iodine from nuclear fuel reprocessing facilities. Environmental science &
technology, 33 (1999) 2536-2542.
[35] R.B. Firestone, The Berkeley laboratory isotope project, Tech. rep., Lawrence Berkeley National Laboratory, 2000. <http://ie.lbl.gov/education/isotopes.htm>.
[36] B. Clement, L. Cantrel, G. Ducros, F. Funke, L. Herranz, A. Rydl, G. Weber, and C.
Wren, State of the art report on iodine chemistry (NEA-CSNI-R--2007-01). Nuclear Energy Agency of the OECD (NEA) (Feb 2007).
[37] X. Hou, V. Hansen, A. Aldahan, G. Possnert, O. C. Lind, and G. Lujaniene, A review on speciation of iodine-129 in the environmental and biological samples. Analytica Chimica Acta, 632 (2009) 181-196.
Chapter 1
24
[38] Q. Hu, J. E, Moran, and V. Blackwood, Geochemical cycling of iodine species in soils (No. UCRL-BOOK-234137). Lawrence Livermore National Laboratory (LLNL), Livermore, CA (2007).
[39] J.D. Hem, Study and interpretation of the chemical characteristics of natural water (Vol. 2254). Department of the Interior, US Geological Survey (1985).
[40] Q. Hu, P. Zhao, J.E. Moran, and J.C. Seaman, Sorption and transport of iodine species in sediments from the Savannah River and Hanford Sites. J. Contam.
Hydrol., 78 (2005) 185-205.
[41] D.I. Kaplan, M.E. Denham, S. Zhang, C. Yeager, C. Xu, K.A. Schwehr, and P.H.
Santschi, Radioiodine biogeochemistry and prevalence in groundwater. Crit. Rev.
Env. Sci. Technol., 44 (2014) 2287-2335.
[42] J. Podder, J. Lin, W. Sun, S.M. Botis, J. Tse, N. Chen, and Y. Pan, Iodate in calcite and vaterite: Insights from synchrotron X-ray absorption spectroscopy and first-principles calculations. Geochim. Cosmochim. Acta, 198 (2017) 218-228.
[43] INTERNATIONAL ATOMIC ENERGY AGENCY, Classification of Radioactive Waste, Safety Series No. 111-G-1.1, IAEA, Vienna (1994).
[44] IAEA, H. Processing of Radioactive Waste from Nuclear Applications (No. 402, pp.
19-20). Technical reports series (2001).
[45] IAEA, Conditioning of Low and Intermediate Level Radioactive Wastes, Technical Reports Series No. 222, IAEA, Vienna (1983).
[46] F.M. LEA, The Chemistry of Cement and Concrete, 3rd edn, Edward Arnold, Glasgow (1970).
[47] R.D. Spence, and C. Shi, (Eds.). Stabilization and solidification of hazardous, radioactive, and mixed wastes. CRC press (2004).
[48] M. Ochs, D. Mallants, and L. Wang, Radionuclide and metal sorption on cement and concrete. Springer (2016).
[49] J.S. Shon, S.H. Lee, H.S. Park, K.J. Kim, and D.K. Min, The improvement of the mechanical stability and leachability of bituminized waste form of radioactive ash by
Chapter 1
25
addition of reused polyethylene. Korean Journal of Chemical Engineering, 18 (2001) 668-672.
[50] W. Koerner, and A. Dagen, On the radiation stability of bituminized radioactive wastes. Isotopenpraxis Isotopes in Environmental and Health Studies, 7 (1971) 296-302.
[51] K. Sakr, M. Sayed, and M. Hafez, Immobilization of radioactive waste in mixture of cement, clay and polymer. Journal of radioanalytical and nuclear chemistry, 256 (2003) 179-184.
[52] J.W. Anthony, R.A. Bideaux, K.W. Bladh, and M.C. Nichols, Handbook of Mineralogy: Borates, Carbonates, Sulfates; Mineral Data Publishing. Tuscon, AZ.
2003
[53] W. Prince, M. Espagne, and P.C. Aı̈tcin, Ettringite formation: A crucial step in cement superplasticizer compatibility. Cem. Concr. Res. 33(2003), 635-641.
[54] I. Odler, and J. Colán-Subauste, Investigations on cement expansion associated with ettringite formation.Cem. Concr. Res.29(1999), 731-735.
[55] P. Kumarathasan, G.J. McCarthy, D.J. Hassett, and F. Debra, Oxyanion substituted ettringites: synthesis and characterization; and their potential role in immobilization of As, B, Cr, Se and V. MRS Proceedings. Cambridge University Press. 178 (1990) 83-104.
[56] D.J. Hassett, G.J. McCarthy, P. Kumarathasan, and D. Pflughoeft-Hassett, Synthesis and characterization of selenate and sulfate-selenate ettringite structure phases.
Mater. Res. Bull. 25 (1990) 1347–1354.
[57] R.B. Perkins, and C.D. Palmer, Solubility of Ca6 [Al (OH) 6] 2 (CrO4) 3· 26H2O, the chromate analog of ettringite; 5–75° C. Applied Geochemistry, 15 (2000) 1203-1218.
[58] H.F.W. Taylor, Crystal structures of some double hydroxide minerals.
Mineralogical Magazine. 39 (1973) 377-389.
Chapter 1
26
[59] M.L.D. Gougar, B.E. Scheetz, and D.M. Roy, Ettringite and C–S–H Portland cement phases for waste ion immobilization: A review. Waste Manage. 1996, 16, 295–303.
[60] D.H. Moon, J.R. Lee, D.G. Grubb, and J.H. Park, An assessment of Portland cement, cement kiln dust and Class C fly ash for the immobilization of Zn in contaminated soils. Environ. Earth Sci. 2010, 61, 1745-1750.
[61] R.L. Norman, S.E. Dann, S.C. Hogg, and C.A. Kirk, Synthesis and structural characterisation of new ettringite and thaumasite type phases: Ca6[Ga(OH)6• 12H2O]2(SO4)3• 2H2O and Ca6[M(OH)6•12H2O]2(SO4)2(CO3)2, M= Mn, Sn. Solid State Sci. 2013, 25, 110-117.
[62] A.A. Kozak, A.J. Kozak, Z. Kowalski, and K. Wieczorek-Ciurowa, Synthesis of the ettringite containing chromium (III) and chromium (VI). Pol. J. Chem. Tech. 2002, 4, 17–18.
[63] M. Zhang and E.J. Reardon, Removal of B, Cr, Mo, and Se from wastewater by incorporation into hydrocalumite and ettringite. Environ. Sci. Technol. 2003, 37, 2947-2952.
[64] N. Saikia, S. Kato, and T. Kojima, Behavior of B, Cr, Se, As, Pb, Cd, and Mo present in waste leachates generated from combustion residues during the formation of ettringite. Environ. Toxicol. Chem. 2006, 25, 1710–1719.
[65] S.C.B. Myneni, S.J. Traina, T.J. Logan, and G.A. Waychunas; Oxyanion behavior in alkaline environments: sorption and desorption of arsenate in ettringite. Environ. Sci.
Technol. 1997, 31, 1761-1768.
[66] B. Guo, K. Sasaki, and T. Hirajima, Selenite and selenate uptaken in ettringite:
Immobilization mechanisms, coordination chemistry, and insights from structure. Cem. Concr. Res. 2017, 100, 166-175.
[67] B. Guo, K. Sasaki, and T. Hirajima, Characterization of the intermediate in formation of selenate-substituted ettringite. Cem. Concr. Res. 2017, 99, 30-37.
Chapter 1
27
[68]P.J. Dunn, D.R., Peacor, P.B., Leavens, and Baum, J. L. Charlesite, a new mineral of the ettringite group, from Franklin, New Jersey. American Mineralogist, 68 (1983), 1033-1037.
[69]D. Nishio-Hamane, M. Ohnishi, K. Momma, N. Shimobayashi, R. Miyawaki, T., Minakawa, and S. Inaba, Imayoshiite, Ca3Al (CO3)[B(OH)4](OH)6· 12H2O, a new mineral of the ettringite group from Ise City, Mie Prefecture, Japan. Mineralogical Magazine, 79 (2015) 413-423.
[70]N.V. Chukanov, S.N. Britvin, K.V. Van, S. Möckel, and A.E. Zadov, Kottenheimite, Ca3Si(OH)6(SO4)2·12H2O, a new member of the ettringite group from the Eifel area, Germany. The Canadian Mineralogist, 50 (2012) 55-63.
[71] D.R. Peacor, P.J. Dunn, and M. Duggan, Sturmanite, a ferric iron, boron analogue of ettringite. The Canadian Mineralogist, 21 (1983) 705-709.
[72]S.J. Barnett, C.D. Adam, and A.R.W. Jackson, Solid solutions between ettringite, Ca6Al2(SO4)3(OH)12· 26H2O, and thaumasite, Ca3SiSO4CO3(OH)6·12H2O. Journal of materials science, 35 (2000) 4109-4114.
[73] A.E. Moore and H.F.W. Taylor, Crystal structure of ettringite. Acta Crystallogr.
B26 (1970) 386–393.
[74] M.R. Hartman, S.K. Brady, R. Berliner, and Conradi M.S.; The evolution of structural changes in ettringite during thermal decomposition. J. Solid State Chem.
179 (2006) 1259-1272.
[75] A. Jiménez, and M. Prieto, Thermal stability of ettringite exposed to atmosphere:
implications for the uptake of harmful ions by cement. Environ. Sci. Technol., 49 (2015) 7957-7964.
[76] Q. Zhou, E. E. Lachowski, and F.P. Glasser, Metaettringite, a decomposition product of ettringite. Cem. Concr. Res., 34 (2004) 703-710.
[77] Q. Zhou, and F.P. Glasser, Thermal stability and decomposition mechanisms of ettringite at< 120 C. Cem. Concr. Res., 31 (2001) 1333-1339.
Chapter 1
28
[78] T.Y. Chen, E.R. Maddrell, N.C. Hyatt, A.S. Gandy, M.C. Stennett, and J.A. Hriljac, Transformation of Cs-IONSIV® into a ceramic wasteform by hot isostatic pressing. J. Nucl. Mater. (2017) in press.
[79] B. Guo, K. Sasaki, and T. Hirajima, Solidification of ettringite after uptaking selenate as a surrogate of radionuclide in glass-ceramics by using industrial by-products. J. Mater. Sci., 52 (2017) 12999-13011.
[80] B. Verbinnen, C., Block, J., Van Caneghem, and C. Vandecasteele, Recycling of spent adsorbents for oxyanions and heavy metal ions in the production of ceramics. Waste Manage., 45 (2015) 407-411.
Chapter 2
29
Chapter 2
Selenite and selenate uptaken in ettringite: Immobilization
mechanisms, coordination chemistry, and insights from structure
Chapter 2
30
