UNLV Retrospective Theses & Dissertations 1-1-2008 The effects of electromagnetic fields on the detection of mercury and radionuclides Yogendra M Panta University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/rtds Repository Citation Panta, Yogendra M, "The effects of electromagnetic fields on the detection of mercury and radionuclides" (2008). UNLV Retrospective Theses & Dissertations. 2831. http://dx.doi.org/10.25669/fdxc-fpx0 This Dissertation is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Dissertation in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/or on the work itself. This Dissertation has been accepted for inclusion in UNLV Retrospective Theses & Dissertations by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. THE EFFECTS OF ELECTROMAGNETIC FIELDS ON THE DETECTION OF MERCURY AND RADIONUCLIDES by Yogendra M. Panta Master of Science in Mechanical Engineering Youngstown State University, Youngstown, Ohio 2004 Bachelor of Engineering in Mechanical Engineering Tribhuvan University, Kathmandu, Nepal 2000 Bachelor of Science in Physical Science Tribhuvan University, Kathmandu, Nepal 1995 A dissertation submitted in partial fulfillment of the requirements for the Doctor of Philosophy Degree in Mechanical Engineering Department of Mechanical Engineering Howard R. Hughes College of Engineering Graduate College University of Nevada, Las Vegas August 2008 UMI Number: 3338521 Copyright 2008 by Panta, Yogendra M. All rights reserved. INFORMATION TO USERS The quality of this reproduction Is dependent upon the quality of the copy submitted. Broken or Indistinct print, colored or poor quality Illustrations and photographs, print bleed-through, substandard margins, and Improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, If unauthorized copyright material had to be removed, a note will Indicate the deletion. UMI UMI Microform 3338521 Copyright 2009 by ProQuest LLC. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 E. Elsenhower Parkway PC Box 1346 Ann Arbor, Ml 48106-1346 Copyright by Yogendra M. Panta 2008 Ali Rights Reserved Dissertation Approval IJNTV The Graduate College University of Nevada, Las Vegas May 1 4 ,2008 The Dissertation prepared by Yogendra M Panha Entitled The Effects of Electromagnetic Fields on the Detection of Mercury and Radionuclides is approved in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Mechanical Engineering Examination Committee Chair Dean of the Graduate College Ext ym\Cornmittee Member \ w Examination Committee Member Examination Committee Member Graduate College Faculty Representative 11 ABSTRACT The Effects of Electromagnetic Fields on the Detection of Mercury and Radionuclides by Yogendra M. Panta Dr. Shizhi Qian, Examination Committee Chair Assistant Professor of Mechanical Engineering University of Nevada, Las Vegas Mercury and many radionuclides are extremely toxic, and their monitoring and detection are of importance for human health and environmental protection. This dissertation focuses on the detection of mercury (II) ions and radionuclides including uranium and plutonium (^^^Pu), and americium (^“^'Am) in aqueous solutions under the effects of electromagnetic fields. The stripping electrochemical method has been widely used to detect mercury (II) ions in aqueous solutions. To enhance the detection sensitivity of the conventional electrochemical method, mechanically stirring the solution is usually performed to enhance the rate of the ionic mass transport. Instead of mechanically stirring the solution; the electrochemical cell is positioned in a magnetic field provided by permanent magnets. The interaction between the current density transmitted through the solution and the magnetic field induces Lorentz force, thus magneto-hydrodynamic (MHD) flow, which can be used to stir and mix the sample solution uniformly without the use of any mechanical moving parts or rotating electrodes. This research develops an ultra sensitive mercury sensor by integrating the MHD with iii the electrochemical analyzer, and with the surface plasmon resonance (SPR) instrument, and its detection limit is obtained down to 1 ppb. To improve the resolution of the alpha spectrum during the detection of ^^^Pu, and ^""Am, hydrous oxides of the radionuclides were electrochemically deposited onto the surface of a steel planchet in the presence of a magnetic field. The steel planchet was then washed and dried, and the energy spectrum emitted was measured with the alpha spectrometer. A homogeneous and thin film with larger grain size was formed during the deposition step due to the induced MHD flow leading to a higher resolution in the detection sensitivity and the alpha spectrum. IV TABLE OF CONTENTS ABSTRACT............................................................................................................................. iii LIST OF ABBREVIATIONS..............................................................................................viii LIST OF SYMBOLS ..............................................................................................................ix LIST OF FIGURES.................................................................... xi ACKNOWLEDGEMENTS................................................................................................xvii CHAPTER 1 INTRODUCTION........................................................................................1 1.1 Motivation .................................................................................................................. 1 1.2 Heavy Metals .............................................................................................................2 1.3 Mercury ...................................................................................................................... 3 1.3.1 History of Mercury Poisoning .................................................................... 3 1.3.2 Effects of Mercury Poisoning ..................................................................... 4 1.3.3 Mercury Cycle ............................................................................................. 5 1.4 Radiation .................................................................................................................... 7 1.4.1 Nuclear and Radiation Disasters ................................................................. 7 1.4.2 Ionizing Radiation ........................................................................................ 7 1.4.3 Effects of Radiation ................................................................................... 10 1.4.4 Radionuclides ..............................................................................................10 1.5 Organization of Dissertation ...................................................................................11 CHAPTER 2 LITERATURE REVIEW.......................................................................... 12 2.1 Toxicity of Mercury.................................................................................................12 2.2 Detection of Mercury under MHD Convection .................................................... 13 2.2.1 Electrochemical Detection of Mercury .....................................................13 2.2.2 Electrochemical SPR Detection of Mercury ............................................ 16 2.3 Radiation Hazards to Human Health ..................................................................... 19 2.4 Detection of Radionuclides under MHD Convection ...........................................20 2.4.1 Electrodeposition of Radionuclides ..........................................................20 2.4.2 Alpha Spectrometric Measurement of Radionuclides Sources .............. 24 CHAPTER 3 ELECTROCHEMICAL DETECTION OF MERCURY UNDER MHD CONVECTION..........................................................................................25 Summary ............................................................................................................................25 3.1 Materials and Methods ............................................................................................ 26 3.1.1 Materials.....................................................................................................26 3.1.1.1 Chemicals and Reagents ............................................................. 26 3.1.1.2 Electrodes ..................................................................................... 27 3.1.1.3 Electrode Polishing .............................................................. 27 3.1.1.4 Magnets for MHD Convection ...................................................29 3.1.2 Methods .......................................................................................................32 3.2 Results and Discussion ...........................................................................................35