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Ml 48106-1346 USA 313/761-4700 800/521-0600 OXYANION-MINERAL SURFACE INTERACTIONS IN ALKALINE ENVIRONMENTS: ASO4 AND C1O4 SORPTION AND DESORPTION IN ETTRINGITE Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Satish Chandra Babu Myneni, M.S., M.Tech. The Ohio State University 1995 Dissertation Committee T.J.Logan S.J.Traina Approved By G.A.Waychunas J.M.Bigham G.Faure Advisor Y.Chin Environmental Sciences Graduate Program UMI Number: 9612249 UMI Microform 9612249 Copyright 1996, by UMI Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. UMI 300 North Zeeb Road Ann Arbor, MI 48103 DEDICATION PAGE ACKNOWLEDGEMENTS I am indebted to several people for their support and encouragement, who deserve special recognition. I would like to express deepest gratitude to my advisers Drs. Terry J. Logan and Samuel J. Traina for their support, and encouragement throughout the three and half years of my stay in Kottmaa I would like to thank Dr. Logan for introducing me to the subject of oxyanions and their play at the mineral-water interfaces. Special thanks to my coadviser (‘Sam’) who created interests in microscopic studies and introducing me to the world of spectroscopy. His unselfishness in sharing his time for discussions is commendable and appreciated. I would like to share with them what ever good that comes out of this dissertation. Although Dr. Waychunas joined the ^execution committee' little later, he has influenced my research career greatly. I would like to thank him for teaching x-ray absorption spectroscopy and showing how to view the experimental data in several different ways. Dr. Bigham and Dr. Faure needs special mention for their encouraging me in this research. I would like to thank Dr. Bigham for introducing me to the mineral world of ‘ettringite’, without which this dissertation would have been directed in some other direction. Dr. Yo Chin showed me the other side of inorganic world and admire him for all the discussions we had in the journal club. Although Dr. Krissek is not a member of my dissertation committee, he needs a special recognition for seeing a ‘potential researcher’ (euphanism for a Ph. D. student ?) in me. His 111 unselfishness in guiding a student is really appreciated. He gave me a new life in my research career. Special thanks to my good friends, Gustavo for technical discussions and encouragement, and Eric and Matt, for sharing my views and introducing me to the American society and culture. I would like to thank Quirine and Valerie (dectron-electron pair correlations) for keeping the life in Rm 409 very social. Ubi, Doug, Brad boy, Billy and Jagat need a special acknowledgment for helping me in several different laboratory analyses. Thanks to all my other friends of Rm 409 for their support and encouragement. I would like to thank Dr. Paul Powliat (Smithsonian Museums), Dr. Douglas Pride, and Dr. Tettenhorst for loaning me mineral samples; and Dr. Ingrid Pickering for EXAFS data collection and analysis. Ultimately, a special acknowledgment goes to my school teacher Donepudi Janakiram, who invigorated my interests in science from my childhood. Now I realize that he is very optimistic about me becoming a scientist. In additioa, the unselfish people of my village, who together started a small school in the comermost untained village in India, are acknowldged, without which 1 would probably have been an illiterate. IV VITA June 24,1966..................................................... Bom- Mynenivaripalem, India 1987 ....................................................................M.Sc., Indian Institute of Technology, Bombay, India 1990 .................................................................... M.Tech., Indian Institute of Technology, Kharagpur, India 1990-199 1 .......................................................... .Research Scientist, Steel Authority of India Ltd., India 1991-199 5 ...........................................................Teaching & Research Associate, The Ohio State University FIELDS OF STUDY Major Field: Environmental Sciences Studies in oxyanion vibrational and XAS spectroscopy, mineral-water interface chemistry, solubility and mineral equilibria, and alkaline waste materials. TABLE OF CONTENTS ACKNOWLEDGMENTS..................................................................................... iii VITA....................................................................................................................... V LIST OF TABLES................................................................................................. ix LISTOFHOURES............................................................................................... xi CHAPTER PAGE I. INTRODUCTION Ettringite: Occurrence, and Crystal Structure........................... 2 Oxyanion Coordination Sites in Ettringite ................................ 3 Resarch Objectives ..................................................................... 8 Approach .................................................................................... 8 Organization ............................................................................... 10 n. SOLUBILITY AND WEATHERING OF ETTRINGITE: GEOCHEMISTRY OF Ca-Al-S04-H20 SYSTEM Introduction................................................................................. 11 Previous Studies on Ettringite Solubility and Geochemistry of the Ca-Al-S 0 4 -H2 0 system............... 12 Experimental Materials and Methods ........................................ 17 Results and Discussion............................................................... 24 Solubility Product of Ettringite.................................................. 24 Incongruent Dissolution of Ettringite and Geochemistry of Ca-Al-S0 4 -H2 0 System................................................ 32 Geochemistry of the Ca-Al-S 0 4 -H2 0 System: Open to Fe^*, M g^ Si( 0 H)4°, and COj^ ............................................... 46 Conclusions................................................................................. 48 m . INTERACTIONS OF ASO4 WITH ETTRINGITE Introduction................................................................................. 49 vi Experimental Materials and Methods ........................................ 51 Results and Discussion............................................................... 54 As0 4 Adsoiption ......................................................................... 55 As0 4 Coprecipitation ................................................................. 6 6 ASO4 Desorption ......................................................................... 6 8 ASO4 Interactions with Ettringite ............................................... 72 Conclusions................................................................................. 76 IV. INTERACTIONS OF C1O 4 WITH ETTRINGITE Introduction................................................................................. 78 Experimental Materials and Methods ........................................ 79 Results and Discussion............................................................... 81 Cr0 4 Adsorption ......................................................................... 82 C1O4 Coprecipitation .................................................................. 8 6 C1O4 Desorption .......................................................................... 89 Cr0 4 Interactions with Ettringite................................................ 89 V. VIBRATIONAL SPECTROSCOPY OF OXYANIONS IN ETTRINGITE Introduction................................................................................ 92 Data Collection and Analysis ..................................................... 95 Results and Discussion............................................................... 99 Coordination Environment of Ca, Al, SO 4, OH and H 2O in Ettringite ................................................................... 99 ASO4 Complexation