Formation of haloacetic acids and N-nitrosodimethylamine via the chlorination of carbon nanotubes

ii ACKNOWLEDGMENTS Firstly, I would like to thank both of my graduate advisors, Dr. David Cwiertny and Dr. Richard Valentine. Dave, thank you for all of your guidance over these last six years. You have truly made a huge impact on my life and career, and I cannot thank you enough for this opportunity. Rich, thank you for your constant encouragement and for sharing with me your vast amount of knowledge. Through all of the ups and downs, you two helped make this experience one of the most rewarding tasks I have accomplished. I would also like to thank everyone in the Cwiertny group and Environmental Engineering department at the University of Iowa. You all have made this journey much more feasible and become great friends along the way. Thank you to Edgard Verdugo for all of his support on this project. I am forever thankful for his willingness to always assist me in my experiments and data analysis. I also have to thank my family and friends back home for all of their love and support throughout this adventure – especially my Mom, Dad, and Emily for their involvement in my life and for providing me with a loving, caring environment. I especially want to thank my fiancée, Allison, for all of her love and support on our journey together. She has been my backbone and has helped me keep my head above the water, even when times were tough. I love you. Lastly, I want to thank God for giving me the patience and strength to succeed in graduate school. I would not have been able to make it through without His love. iii ABSTRACT Recent investigations have shown that engineered nanomaterials such as carbon nanotubes (CNTs) are a source and precursor for disinfection byproduct (DBP) formation. The aim of this study was to extend previous research of CNTs by investigating the potential for other classes of CNTs to generate disinfection byproducts (DBP) during chlorination. We examined particular types of CNTs with surface groups analogous to suspected model precursors for DBP formation. Specifically, we conducted experiments to determine the formation of haloacetic acids (HAAs) and N-nitrosodimethylamine (NDMA) via the chlorination of carbon nanotubes. Polymer coated CNTs generated the greatest total HAA concentration of up to 170 µg-HAA/mg-CNT. Results showed that the presence of surface oxide groups (e.g. surface carboxylic acid groups) promotes HAA formation. We observed a strong …