terrestrial biotic ligand model (tblm) for copper, and nickel toxicities to plants, invertebrates, and microbes in soils

TERRESTRIAL BIOTIC LIGAND MODEL (TBLM) FOR COPPER, AND NICKEL TOXICITIES TO PLANTS, INVERTEBRATES, AND MICROBES IN SOILS by Sagar Thakali A dissertation submitted to the Faculty of the University of Delaware in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Civil Engineering. Spring 2006 Copyright 2006 Sagar Thakali All Rights Reserved UMI Number: 3221133 3221133 2007 UMI Microform Copyright All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, MI 48106-1346 by ProQuest Information and Learning Company. TERRESTRIAL BIOTIC LIGAND MODEL (TBLM) FOR COPPER, AND NICKEL TOXICITIES TO PLANTS, INVERTEBRATES, AND MICROBES IN SOILS by Sagar Thakali Approved: __________________________________________________________ Michael J. Chajes, Ph.D. Chair of the Department of Civil and Environmental Engineering Approved: __________________________________________________________ Eric W. Kaler, Ph.D. Dean of the College of Engineering Approved: __________________________________________________________ Conrado M. Gempesaw II, Ph.D. Vice Provost for Academic and International Programs I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: __________________________________________________________ Herbert E. Allen, Ph.D. Professor in charge of dissertation I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: __________________________________________________________ William R. Berti, Ph.D. Member of dissertation committee I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: __________________________________________________________ Ronald T. Checkai, Ph.D. Member of dissertation committee I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: __________________________________________________________ Dominic M. Di Toro, Ph.D. Member of dissertation committee I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy. Signed: __________________________________________________________ Donald L. Sparks, Ph.D. Member of dissertation committee v ACKNOWLEDGMENTS I express my profound gratefulness to my advisor and mentor Professor Herbert E. Allen without whose extraordinary patience, guidance, and advice the completion of this work was not possible. I am equally thankful to Professor Dominic M. Di Toro who provided me with extensive assistance, guidance, and advice in the course of this study. I am grateful to the Center for Study of Metals in the Environment (CSME) at the Universidy of Delaware, the International Copper Association (ICA), and the Nickel Producers Environmental Research Association (NiPERA) for funding this study. I am also grateful to Dr. William R. Berti, Dr. Ronald T. Checkai and Professor Donald L. Sparks, for their service in my dissertation committee and for providing me with comments and suggestions which have greatly improved the quality of this study. I thank my collaborators, Dr. Alexander A. Ponizovsky, Ms. Corrine P. Rooney, Dr. Fang-Jie Zhao, Dr. Steve P. McGrath, Ms. Peggy Criel, Ms. Hilde Van Eckout, Professor Collin C. Janssen, Dr. Koen Oorts and Professor Erik M. Smolders. They have been very gracious in providing me with the data necessary for this study. I want to express my sincere appreciation to Ms. Dana M. Crumety for offering me help always, to Mr. Douglas J. Baker, Mr. Michael J. Davidson, Mr. Eric C. Eckman and Ms. Lucille Z. Short for all their help, and to my colleagues, Dr. Zhenqing Shi, Mr. David M. Metzler, Mr. Akash Sondhi and Mr. Sammy Lin for their friendship and much more. vi I would like to thank my family for all the love and support that they gave me. I am grateful to my grand parents, Mr. and Mrs. Gyan B. Thakali, and parents, Mr. Gopal S. Thakali and Mrs. Kamala Thakali, for all the sacrifices they have made so I can do what I do. I am grateful to my siblings, Mrs. Prabha S. Subba, Ms. Muna Thakali and Mr. Deep S. Thakali, who have always been there to support in my struggles and rejoice in my happiness. Finally, I would like to express the most sincere gratefulness to my wife, Jasmeen Hirachan, for putting up with me and my ways and loving me back even when I do not deserve. Without her all my effort will have no meaning. vii TABLE OF CONTENTS LIST OF TABLES xi LIST OF FIGURES xv ABSTRACT xxii Introduction 1 1.1 Background 1 1.2 The overall objective 4 1.3 The structure of the dissertation 4 1.4 References 6 Literature review 9 2.1 Bioavailability and ecotoxicity of metals in soils 9 2.2 Understanding metal speciation in soils 17 2.2.1 Total metal content of soils 18 2.2.2 Soil organic matter (SOM) 19 2.2.3 Oxides, carbonates and clays 20 2.2.4 Dissolved organic carbon (DOC) 21 2.2.5 pH 22 2.2.6 Dissolved cations 23 2.3 Modeling metal speciation 24 2.4 Summary and Conclusions 29 2.5 References 30 The terrestrial biotic ligand model 39 3.1 Introduction 39 3.2 The Windermere Humic Aqueous Model (WHAM VI) 41 3.2.1 Sub-model for humic substances 43 3.2.2 Sub-model for oxides 46 3.2.3 Sub-model for cation exchange 46 3.2.4 Limitations in modeling with WHAM VI 47 3.3 The toxicity model 48 3.4 The estimation of model parameters 51 3.5 References 52 Material and methods 55 4.1 Characterization of the soils 55 4.2 Experimental procedure for Cu and Ni partitioning and speciation 56 4.3 The bioassay experiments 60 4.3.1 Plant bioassays 60 4.3.1.1 Barley root elongation 61 viii 4.3.1.2 Tomato shoot growth 62 4.3.2 Invertebrate bioassays 62 4.3.2.1 Redworm cocoon production 62 4.3.2.2 Springtail juvenile production 63 4.3.3 Microbial bioassays 64 4.3.3.1 Potential nitrification rate 64 4.3.3.2 Glucose induced respiration 65 4.4 References 65 Modeling copper speciation 68 5.1 Introduction 68 5.2 Materials and Methods 69 5.3 Results and Discussions 70 5.3.1 The whole soil approach 70 5.3.1.1 Active organic matter 70 5.3.1.2 Phases besides SOM 74 5.3.1.3 Competitive binding of Fe 3+ and Al 3+ 75 5.3.1.4 Sensitivity of calculated pCu to DOC 76 5.3.1.5 Sensitivity of calculated pCu to dissolved cations and P CO 2 77 5.3.1.6 Final calculations using the whole soil approach 80 5.3.2 The solution approach 80 5.3.3 Predicting the dissolved Cu concentration 84 5.4 Summary and Conclusions 86 5.5 References 87 Modeling nickel partitioning in soils 90 6.1 Introduction 90 6.2 Materials and Methods 92 6.3 Results and Discussions 93 6.3.1 Active soil organic matter 93 6.3.2 Competitive binding by Fe 3+ and Al 3+ 94 6.3.3 Prediction of Ni 2+ activity 98 6.3.4 Sensitivity of the calculations to dissolved cations 99 6.3.5 Final Calculations using WHAM VI 99 6.3.6 Assessment of soils with OC content < 1% 101 6.4 Summary and Conclusions 105 6.5 References 105 Copper, and nickel toxicities to barley root elongation 109 7.1 Introduction 109 7.2 Experimental and Data Analysis Methods 111 7.2.1 Selection of soils 111 7.2.2 Bioassays 111 7.2.3 Whole soil metal speciation using WHAM VI 112 ix 7.2.4 Toxicity equations 113 7.2.5 Estimation of model parameters 113 7.3 Results and Discussion 114 7.3.1 WHAM VI speciation 114 7.3.2 Estimation of the TBLM parameters 117 7.3.3 Dose-response relationships 125 7.3.3.1 Nickel toxicity 125 7.3.3.2 Copper toxicity 131 7.3.4 Interaction of cations with the biotic ligand 131 7.3.5 Prediction of the EC50 total metal concentrations 135 7.4 Summary and Conclusions 137 7.5 References 138 TBLM for plants, invertebrates, and microbes 142 8.1 Introduction 142 8.2 Experimental and Modeling Methods 143 8.2.1 Bioassays 143 8.2.2 Estimating the EC50 values for individual soils 144 8.2.3 Whole soil metal speciation using WHAM VI 145 8.2.4 Estimation of model parameters 146 8.3 Results and Discussion 147 8.3.1 Estimation of model parameters 147 8.3.2 Dose-response relationships 153 8.3.3 Interaction of cations with the biotic ligand 178 8.3.4 The extent of the protective effect of the competing cations 180 8.3.5 Prediction of EC50 183 8.4 Summary and Conclusions 186 8.5 References 187 Copper, and nickel toxicities in calcareous soils 190 9.1 Introduction 190 9.2 Bioassay and soil solution composition data 193 9.3 Modeling approach 194 9.4 Results and Discussion 196 9.4.1 Dose response relationships for the BRE bioassays 196 9.4.2 Prediction of the EC50 values 201 9.5 Summary and Conclusions 204 9.6 References 204 Final conclusions and recommendations 207 Appendix A 211 Appendix B 223 Appendix C 289 Appendix D 293 Appendix E 306 [...]... study, which incorporates Cu, and Ni toxicities to six different endpoints associated with higher plants, invertebrates, and microbes for up to eleven non-calcareous soils of disparate properties is, to my knowledge, the first one to use a single theoretical framework for modeling metals’ toxicities in terrestrial systems Its xxiv encouraging performance in the majority of the soils considered in this study... metals ecotoxicities and speciation in soils is given The evidence for a BLM-type interaction of the cations with the soil biota is presented A discussion of various approaches to modeling partitioning and speciation of metals in soils and on the available computational models are also presented In Chapter 3 the TBLM is described and formulated Its sub -model for metal speciation is discussed and the toxicity... processes varied nineteen to ninety fold in eighteen soils (Oorts et al., 2006) Clearly, the total metal concentration in soils is a poor indicator of its bioavailability to soil invertebrates, plants and microbes In the context of Pb toxicity to earthworms in soils, Lanno et al (2004) reports that the bioavailability of metals in soils can be modified dramatically by soil properties and consequently,... approach for insights into the competitive interaction of the cations, and assessing metal toxicities in a complex and heterogeneous soil system Therefore, this study has achieved a significant advancement in assessing the bioavailability and toxicities of metals in terrestrial systems, which is a significant part of environmental risk assessment xxv Chapter 1 INTRODUCTION 1.1 Background Contamination of soils. .. data for Cu and Ni 196 Table A-1 Data for copper partitioning and speciation study (DOC and DIC refer to dissolved organic and inorganic carbon, respectively) 212 Table A-2 Data for nickel partitioning and speciation study (DOC and DIC refers to dissolved organic and inorganic carbon, respectively) 217 Table B-1 Soil and soil solution properties and the bioassay data for Cu toxicity to. .. developed for Cu, and Ni toxicities to barley root elongation in Chapter 7 is extended to the remaining five endpoints to demonstrate the general applicability of the approach In Chapter 9 the possible incorporation of calcareous soils into the TBLM framework is discussed Instead of the whole soil approach to speciation in 5 these soils, for reasons that will be discussed, WHAM VI will be applied for speciation... summary and the optimum parameters associated with the three models 126 Table 8.1 The non-calcareous soils excluded for the analyses in this study for each of the bioassays 145 Table 8.2 The dose-response parameters (EC50 and β) for the three models considered: Total Cu Model (Total Cu), the Free Ion Activity Model (FIAM) and the Terrestrial Biotic Ligand Model (TBLM) The binding constants... (Eisenia Andrei) varied between 0 to 100% in twenty one soils of varying properties even though each was amended with 2000 mg Pb kg-1 soil In a study of Cu toxicity to barley root elongation and tomato shoot yield, the EC50 total metal concentration varied by fifteen and thirty nine fold, respectively, among eighteen soils (Rooney et al., 2006) Similarly the toxicity thresholds for Cu, and Ni toxicities to. .. parameters (EC50 and β) for the three models considered: Total Ni Model (Total Ni), the Free Ion Activity Model (FIAM) and the Terrestrial Biotic Ligand Model (TBLM) The binding constants are associated with the TBLM 152 xi Table 9.1 The distribution of Cu and Ni in 5 calcareous soils (Moral et al., 2005) Only the approximate ranges are listed 191 Table 9.2 Summary of the model fits to the barley... was to develop the TBLM and demonstrate its applicability to Cu, and Ni toxicities to six different endpoints in a wide range of soils In doing so, the study will provide a potentially valuable tool for metals risk assessment in soils 1.3 The structure of the dissertation To address the issues and the goals identified here, the thesis is organized as follows: 4 In Chapter 2 a review of the existing . by ProQuest Information and Learning Company. TERRESTRIAL BIOTIC LIGAND MODEL (TBLM) FOR COPPER, AND NICKEL TOXICITIES TO PLANTS, INVERTEBRATES, AND MICROBES IN SOILS by. TERRESTRIAL BIOTIC LIGAND MODEL (TBLM) FOR COPPER, AND NICKEL TOXICITIES TO PLANTS, INVERTEBRATES, AND MICROBES IN SOILS by Sagar Thakali A dissertation submitted to. parameters (EC50 and β ) for the three models considered: Total Cu Model (Total Cu), the Free Ion Activity Model (FIAM) and the Terrestrial Biotic Ligand Model (TBLM). The binding constants