Source Apportionment of Ambient Mercury at Flin Flon, Manitoba
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University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations Theses, Dissertations, and Major Papers 7-15-2019 Source Apportionment of Ambient Mercury at Flin Flon, Manitoba Morounfolu Adeyeye University of Windsor Follow this and additional works at: https://scholar.uwindsor.ca/etd Recommended Citation Adeyeye, Morounfolu, "Source Apportionment of Ambient Mercury at Flin Flon, Manitoba" (2019). Electronic Theses and Dissertations. 7774. https://scholar.uwindsor.ca/etd/7774 This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are made available for personal study and research purposes only, in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution, Non-Commercial, No Derivative Works). Under this license, works must always be attributed to the copyright holder (original author), cannot be used for any commercial purposes, and may not be altered. Any other use would require the permission of the copyright holder. Students may inquire about withdrawing their dissertation and/or thesis from this database. For additional inquiries, please contact the repository administrator via email ([email protected]) or by telephone at 519-253-3000ext. 3208. Source Apportionment of Ambient Mercury at Flin Flon, Manitoba by Morounfolu Adeyeye A Thesis Submitted to the Faculty of Graduate Studies through the Department of Civil and Environmental Engineering in Partial Fulfilment of the Requirements for the Degree of Master of Applied Science at the University of Windsor Windsor, Ontario, Canada © 2019 Morounfolu Adeyeye Source apportionment of ambient mercury at Flin Flon, Manitoba by Morounfolu Adeyeye APPROVED BY: T. Bolisetti Department if Civil and Environmental Engineering P. Henshaw Department of Civil and Environmental Engineering X. Xu, Advisor Department of Civil and Environmental Engineering July 15, 2019 ii DECLARATION OF ORIGINALITY I hereby certify that I am the sole author of this thesis and that no part of this thesis has been published or submitted for publication. I certify that, to the best of my knowledge, my thesis does not infringe upon anyone’s copyright nor violate any proprietary rights and that any ideas, techniques, quotations, or any other material from the work of other people included in my thesis, published or otherwise, are fully acknowledged in accordance with the standard referencing practise. Furthermore, to the extent that I have included copyrighted material that surpasses the bounds of fair dealing within the meaning of the Canada Copyright Act, I certify that I have obtained a written permission from the copyright owner(s) to include such material(s) in my thesis and have included copies of such copyright clearances to my appendix. I declare that this is a true copy of my thesis, including any final revisions, as approved by my thesis committee and the Graduate Studies office, and that this thesis has not been submitted for a higher degree to any other University or Institution. iii ABSTRACT The sources and processes, including re-emission of gaseous elemental mercury, affecting speciated atmospheric mercury (Hg) at Flin Flon, Manitoba were identified and quantified using the positive matrix factorisation (PMF) model and principal component analysis (PCA). The input data contain the concentrations of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), particulate-bound mercury (PBM), PM2.5and its components (elements and ions), sulphur dioxide (SO2) as well as temperature, precipitation, relative humidity and wind speed. Eighty-one daily samples and twenty chemical species concentrations as well as meteorological parameters, measured from July 2010 to May 2011, were analysed. PMF identified six factors, namely secondary aerosol and re-emission, industrial, crustal/soil dust, road salt/biomass burning, Hg oxidation and coal combustion. Among the factors, secondary aerosol and re-emission, road salt/biomass burning and bromine source profiles contained one or two Hg forms. The bromine source and, secondary aerosol and re- emission were the dominant GEM contributing factors with average contributions of 48% and 43%, respectively. PMF most closely predicted the observed daily concentrations of PBM then GOM and PBM. PCA of the same concentration data set extracted six principal components. These were largely consistent with the PMF factors. A component identified as long-range transport of Hg with loadings on GEM and GOM only was identified by PCA. With inclusion of meteorological data in the input, the long-range transport of Hg was divided into re-emission and a new component, dispersion of GEM. Overall, PCA identified three Hg-associated components, including re-emission of GEM. The long-range transport of Hg predominantly contributed to GEM in PCA of dataset. The dispersion component’s contribution to GEM was dominant when meteorological data was included in the input. PCA most closely predicted PBM then GOM and GEM, regardless of whether or not meteorological data was included. iv DEDICATION To the Almighty God, my parents, my siblings and my wife. v ACKNOWLEDGEMENTS I am thankful to everyone who contributed to my success in writing this thesis. My deep appreciation goes to my supervisor, Dr Iris Xu, for her supervision and support during my study in University of Windsor. My appreciation goes to the Department Head, Dr Paul Henshaw and my committee members, for their constructive comments and suggestions on my thesis. I appreciate Tianchu Zhang for his assistance during the data processing stage of this work. I am thankful to Environment and Climate Change Canada for providing the data and funding assistance to undertake this project. I acknowledge the United States Environmental Protection Agency (USEPA) for the PMF5.0 model used in the study. I deeply thank my parents Mr & Mr S.A. Adeyeye, my siblings and their families for their prayers, love and support throughout my master’s degree program in the University of Windsor. I also want to thank my amiable, loving and caring wife, Olayemi for standing by me all through my study in the university. Thank you all and God bless. vi TABLE OF CONTENTS DECLARATION OF ORIGINALITY …………………………………………………….iii ABSTRACT ……………………………………………………………………………….iv DEDICATION ………………………………………………………………………………v ACKNOWLEDGEMENTS ……………………………………………………………….vi LIST OF TABLES ………………………………………………………………………….x LIST OF FIGURES ………………………………………………………………………..xi CHAPTER 1 INTRODUCTION ……………………………………………………………1 1.1 Background ……………………………………………………………………….1 1.2 Objectives …………………………………………………………………………6 CHAPTER 2 LITERATURE REVIEW …………………………………………………….8 2.1 Mercury in the Environment ………………………………………………………8 2.1.1Chemistry of atmospheric Hg …………………………………………….8 2.1.2Mercury cycle …………………………………………………………….9 2.2 Fate, Transformation and Transport of Atmospheric Hg ………………………11 2.2.1Emissions ……………………………………………………………………….11 2.2.2Transformation and transport ………………………………………….11 2.2.3Deposition ……………………………………………………………….12 2.2.4Re-emission ………………………………………………………………13 2.3 Health Impacts from Exposure to Hg ……………………………………………14 2.4 Source Apportionment Methods …………………………………………………15 2.4.1 Source apportionment by PMF model ………………………………….16 2.4.2 Source apportionment by PCA ……………………………………………….20 2.4.3 Treatment of missing data ………………………………………………25 2.5 Past studies of source apportionment of speciated atmospheric Hg ……………26 2.6 Inter-comparison of receptor models …………………………………………………28 CHAPTER 3 METHODOLOGY ………………………………………………………….30 3.1 Study Area ……………………………………………………………………….30 3.2 Monitoring data ………………………………………………………………….32 3.2.1 Speciated Hg …………………………………………………………….32 3.2.2 PM2.5 speciation …………………………………………………………33 3.2.3 Sulphur Dioxide (SO2) ...........................................................................34 3.3.4 Meteorological data …………………………………………………….35 3.3 Emission Data ……………………………………………………………………35 3.4 Data screening ....................................................................................................36 3.4.1 Below detection limit …………………………………………………….38 3.4.2 Linear correlation test ………………………………………………….39 3.4.3 Outliers ………………………………………………………………….40 3.5 Data Processing …………………………………………………………………40 3.6 Treatment of missing data ………………………………………………………42 3.7 Choice of receptor models ……………………………………………………….43 3.8 PMF Model setup and performance evaluation …………………………………44 3.9 PCA setup and performance evaluation …………………………………………47 3.10 Estimation of PCA components contributions ………………………………….49 vii CHAPTER 4 RESULTS AND DISCUSSION …………………………………………….51 4.1 PMF Results ……………………………………………………………………51 4.1.1 Estimation of number of factors …………………………………………51 4.1.2 Comparison of 5, 6 and 7-factors profiles ………………………………52 4.1.3 Comparison of 5, 6 and 7 factors’ distribution of scaled residual ……..54 4.1.4 Comparison of 5, 6 and 7 factors regression statistics …………………56 4.1.5 Interpretation of PMF factors ………………………………………….57 4.1.6 Seasonal and overall source contributions ……………………………..63 4.1.7 Performance of PMF using pred/obs scatter plot ………………………66 4.1.8 Performance of PMF using pred/obs time series plot …………………..68 4.2 PCA Results………………………………………………………………………70 4.2.1 Suitability of data set…………………………………………………….70 4.2.2 Selection of component to retain in PCA of dataset …………………….71 4.2.3 PCA results from concentration dataset ………………………………..72 4.2.4 PCA factor contributions to ambient Hg derived from data set ………76 4.2.5