University of Central Florida STARS Electronic Theses and Dissertations, 2004-2019 2006 In-situ Ammonia Removal Of Leachate From Bioreactor Landfills Nicole Berge University of Central Florida Part of the Environmental Engineering Commons Find similar works at: https://stars.library.ucf.edu/etd University of Central Florida Libraries http://library.ucf.edu This Doctoral Dissertation (Open Access) is brought to you for free and open access by STARS. It has been accepted for inclusion in Electronic Theses and Dissertations, 2004-2019 by an authorized administrator of STARS. For more information, please contact [email protected]. STARS Citation Berge, Nicole, "In-situ Ammonia Removal Of Leachate From Bioreactor Landfills" (2006). Electronic Theses and Dissertations, 2004-2019. 776. https://stars.library.ucf.edu/etd/776 IN-SITU AMMONIA REMOVAL OF LEACHATE FROM BIOREACTOR LANDFILLS by NICOLE D. BERGE B.S. University of South Carolina, 1999 M.S. University of South Carolina, 2001 A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Civil and Environmental Engineering in the College of Engineering and Computer Science at the University of Central Florida Orlando, Florida Spring Term 2006 Major Professor: Debra R. Reinhart ABSTRACT A new and promising trend in solid waste management is to operate the landfill as a bioreactor. Bioreactor landfills are controlled systems in which moisture addition and/or air injection are used as enhancements to create a solid waste environment capable of actively degrading the biodegradable organic fraction of the waste. Although there are many advantages associated with bioreactor landfills, some challenges remain. One such challenge is the ammonia-nitrogen concentration found in the leachate. The concentrations of ammonia-nitrogen tend to increase beyond concentrations found in leachate from conventional landfills because recirculating leachate increases the rate of ammonification and results in accumulation of higher levels of ammonia-nitrogen concentrations, even after the organic fraction of the waste is stabilized. Because ammonia-nitrogen persists even after the organic fraction of the waste is stabilized, and because of its toxic nature, it is likely that ammonia-nitrogen will determine when the landfill is biologically stable and when post-closure monitoring may end. Thus an understanding of the fate of nitrogen in bioreactor landfills is critical to a successful and economic operation. Ammonia-nitrogen is typically removed from leachate outside of the landfill. However, additional costs are associated with ex-situ treatment of ammonia, as separate treatment units on site must be maintained or the leachate must be pumped to a publicly owned wastewater treatment facility. Therefore, the development of an in-situ nitrogen removal technique would be an attractive alternative. Several recent in-situ treatment approaches have been explored, but lacked the information necessary for field-scale ii implementation. The objectives of this study were to develop information necessary to implement in-situ ammonia removal at the field-scale. Research was conducted to evaluate the kinetics of in-situ ammonia removal and to subsequently develop guidance for field-scale implementation. An aerobic reactor and microcosms containing digested municipal solid waste were operated and parameters were measured to determine nitrification kinetics under conditions likely found in bioreactor landfills. The environmental conditions evaluated include: ammonia concentration (500 and 1000mg N/L), temperature (25o, 35o and 45oC), and oxygen concentration in the gas-phase (5, 17 and 100%). Results suggest that in-situ nitrification is feasible and that the potential for simultaneous nitrification and denitrification in field-scale bioreactor landfills is significant due to the presence of both aerobic and anoxic areas. All rate data were fitted to the Monod equation, resulting in an equation that describes the impact of pH, oxygen concentration, ammonia concentration, and temperature on ammonia removal. In order to provide design information for a field-scale study, a simple mass balance model was constructed in FORTRAN to forecast the fate of ammonia injected into a nitrifying portion of a landfill. Based on model results, an economic analysis of the in-situ treatment method was conducted and compared to current ex-situ leachate treatment costs. In-situ nitrification is a cost effective method for removing ammonia-nitrogen when employed in older waste environments. Compared to reported on-site treatment costs, the costs associated with the in-situ ammonia removal process fall within and are on the lower end of the range found in the literature. When compared to treating the iii leachate off-site, the costs of the in-situ ammonia removal process are always significantly lower. Validation of the laboratory results with a field-scale study is needed. iv ACKNOWLEDGMENTS First and foremost, I would like to begin by thanking my advisor, Dr. Debra Reinhart, without whom this work would not have been possible. Dr. Reinhart has played many roles during my time here. She has been an extraordinary role model, mentor, friend and critic, exerting an influential impact on my future and helping to shape me both as an aspiring researcher and teacher. She has taught me how to be strong, positive, and have confidence, as she always had immense confidence in me. I have also learned from her the role teaching and research have in life and how much passion for both makes all the difference. I also thank her for providing me with numerous professional development opportunities, such as teaching and attending many conferences. Her willingness to reply to the countless daily emails I sent and for always being available when I needed to blow off steam have been invaluable. One truly could not ask for a better mentor and I feel blessed to have had the opportunity to get to know and work with her. I truly believe that I am leaving UCF not only with a better understanding of theories and as a better researcher, but also as a better person because of all I learned from her. I would also like to thank Dr. John Dietz for all of his help during the past few years. Thank you, Dr. Dietz, for being so helpful and gracious with your time. I have learned so much from you. Dr. Dietz always dropped by my office to help with my, at times quite numerous, problems or to give advice as to how to interpret results. He taught me how to be critical of all results and how to truly understand the inherent limitations associated with them. His help and expertise were invaluable to this work and I really cannot express the immense gratitude I have for all he has done for me. And yes, Dr. Dietz, I did finish before you retired! I just made it…barely! v I also would like to thank my other committee members. Dr. Tim Townsend has offered invaluable guidance to this work. His comments and critiques have made this project better and I greatly appreciate all of his time and support. Thanks also go to Dr. Andrew Randall for agreeing to serve on my committee and for always being willing to help me sort through microbiological issues. I also thank Dr. Ni-Bin Chang, who enthusiastically joined my committee late in the process and was so willing to help and positively contribute to this work. Thank you all so much. I also acknowledge the Florida Center for Solid and Hazardous Waste and the Environmental Research and Education foundation for funding this work. This work would not have possible without your contributions. Thanks also go to Jackie Ceather, who helped me tremendously with some of the laboratory work. Her help and time were greatly appreciated. I would not have slept during the past five years if it weren’t for her. Thanks also go to my fellow research group colleagues, particularly those who spent so much time in the lab with me (Eyad, Lucia and Andrea). I also would like to extend thanks to my dear friends Sara and Bryan Stone. I couldn’t have made it without all of your support. You guys helped to keep me somewhat sane through this process and always reminded me why I was here. Finally, I thank my family for their enduring love and support. My Mom always taught me that if I worked hard and believed in myself, I could accomplish anything. And she was right. Thanks for always being supportive. I also thank my Step-Dad for all of his support and wisdom throughout the years. And, of course, I thank my little brothers, Weber and Mattison, whom I cherish more than anything. I am finally graduating, guys! vi TABLE OF CONTENTS LIST OF TABLES ............................................................................................................ xi LIST OF FIGURES......................................................................................................... xii CHAPTER 1 INTRODUCTION ....................................................................................... 1 Background Information.............................................................................................. 1 Research Objectives and Scope of Work.................................................................... 4 Dissertation Organization ............................................................................................ 6 References......................................................................................................................7 CHAPTER 2 THE FATE OF NITROGEN IN BIOREACTOR LANDFILLS