University of Central Florida STARS Electronic Theses and Dissertations, 2004-2019 2009 Post Treatment Alternatives For Stabilizing Desalinated Water Susaye Douglas 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 Masters Thesis (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 Douglas, Susaye, "Post Treatment Alternatives For Stabilizing Desalinated Water" (2009). Electronic Theses and Dissertations, 2004-2019. 4065. https://stars.library.ucf.edu/etd/4065 POST TREATMENT ALTERNATIVES FOR STABILIZING DESALINATED WATER by SUSAYE S DOUGLAS B.S. University of Central Florida, 2007 A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in the Department of Civil, Environmental, and Construction Engineering in the College of Engineering and Computer Science at the University of Central Florida Orlando, Florida Summer Term 2009 ©2009 Susaye S Douglas ii ABSTRACT The use of brackish water and seawater desalination for augmenting potable water supplies has focused primarily on pre-treatment, process optimization, energy efficiency, and concentrate management. Much less has been documented regarding the impact of post-treatment requirements with respect to distribution system. The goals of this study were to review current literature on post-treatment of permeate water, use survey questionnaires to gather information on post-treatment water quality characteristics, gather operation information, review general capital and maintenance cost, and identify appropriate “lessons learned” with regards to post-treatment from water purveyors participating in the Project. A workshop was organized where experts from across the United States, Europe and the Caribbean active in brackish and seawater desalination, gathered to share technical knowledge regarding post-treatment stabilization, identify solutions for utilities experiencing problems with post-treatment, note lessons learned, and develop desalination water post-treatment guidelines. In addition, based on initial workshop discussions, the iodide content of reverse osmosis and nanofiltration permeate from two seawater desalination facilities was determined. The literature review identified that stabilization and disinfection are required desalination post-treatment processes, and typically are considerations when considering 1) blending, 2) re- mineralization, 3) disinfection, and 4) materials used for storage and transport of product water. Addition of chemicals can effectively achieve post-treatment goals although considerations relating to the quality of the chemical, dosage rates, and possible chemical reactions, such as possible formation of disinfection by-products, should be monitored and studied. The survey gathered information on brackish water and seawater desalination facilities with specific regards to their post-treatment operations. The information obtained was divided into seven iii sections 1) general desalination facility information, 2) plant characteristics with schematics, 3) post- treatment water quality, 4) permeate, blend, and point of entry quality, 5) post-treatment operation, 6) operation and maintenance costs, 7) and lessons learned. A major consideration obtained from the survey was that facilities should conduct post-treatment pilot studies in order to identify operational problems that may impact distributions systems prior to designing the plant. Effective design and regulation considerations will limit issues with permitting for the facility. The expert workshop identified fourteen priority issues pertaining to post-treatment. Priority issues were relating to post-treatment stabilization of permeate water, corrosion control, disinfection and the challenges relating to disinfection by-product (DBP) formation, water quality goals, blending, and the importance of informing the general public. For each priority issues guidelines/recommendations were developed for how facilities can effectively manage such issues if they arise. One of the key priorities identified in the workshop was related to blending of permeate and formation of DBPs. However, it was identified in the workshop that the impact of iodide on iodinated-DBP formation was unknown. Consequently, screening evaluations using a laboratory catalytic reduction method to determine iodide concentrations in the permeate of two of the workshop participants: Tampa Bay and Long Beach seawater desalination facilities. It was found that the permeate did contain iodide, although at levels near the detection limit of the analytical method (8 µg/L). iv This Thesis is dedicated to my parents, grandpa, and especially my sisters Tricia, Karone, and Kamala for all the love and support they have given me. v ACKNOWLEDGEMENTS Special thanks to Dr. Steven Duranceau for serving as my advisor and for his patience, guidance, and support through this project. I want to thank Dr. David Cooper for his advice and encouragement at times when I needed it the most. Thanks to Dr. Andrew Randall for serving on my committee. Thanks to the Water Research Foundation for funding this project and the National Water Research Institute (NWRI) for providing workshop assistance. Thanks to the following utilities for participating in the project, their time and valuable input that was necessary for completion of this project and is greatly appreciated. Irvine Ranch Water District, Irvine, CA Carl Spangenberg San Diego County Water Authority, San Diego, CA Cesar Lopez, Jr. MWD of Southern California, Los Angeles, CA Sun Liang Long Beach Water Department, Long Beach, CA Robert Cheng City of Pompano Beach, Pompano Beach, FL Donald Baylor Collier County Utilities, Naples, FL Steven Messner Tampa Bay Water, Tampa, FL Christine Owen Town of Jupiter Utilities, Jupiter, FL Paul Jurczak El Paso Public Water Utilities Services, El Paso, TX Fernie Rico Naval Facilities Engineering Command, Norfolk, VA James Harris Consolidated Water Company, LTD, Cayman Islands John Countz PWN Water Supply Co. North Holland, Netherlands Gilbert Galjaard Thanks to Maria Pia Real-Robert, Nancy P. Holt, William J. Johnson, Vito Trupiano, and Jayapregasham Tharamapalan for their help when I needed the most, and a special thanks to Amalia vi Abdel-Wahab for her time spent with me in the laboratory completing iodide testing. All your time and effort is sincerely appreciated. vii TABLE OF CONTENTS LIST OF FIGURES ........................................................................................................................................ xii LIST OF TABLES ......................................................................................................................................... xiv LIST OF ACRONYMS .................................................................................................................................. xv CHAPTER ONE: INTRODUCTION ......................................................................................................... 1 Overview ......................................................................................................................................................... 1 Study Objective .............................................................................................................................................. 2 Background ..................................................................................................................................................... 2 Desalination for Drinking Water Production ....................................................................................... 2 Synthetic Membrane Processes ............................................................................................................... 3 Theory ............................................................................................................................................................. 5 Osmosis ...................................................................................................................................................... 5 Osmotic Flow ............................................................................................................................................ 6 Permeate Concentration ......................................................................................................................... 10 CHAPTER TWO: LITERATURE REVIEW ............................................................................................ 16 Permeate Post-treatment ............................................................................................................................ 16 Introduction ............................................................................................................................................. 16 Permeate Conditioning and Blending ................................................................................................... 16 Municipal Methods .................................................................................................................................. 17 Water Quality Considerations ...................................................................................................................