Project Report

Pharmaceuticals in Our Water: A New Zealand Perspective Every time someone takes a prescription or over-the-counter medicine, only a portion of the drug is metabolized by their body. The remainder is excreted in active pharmaceutical form and makes its way through a sewage treatment plant to natural bodies of water, and eventually perhaps to our drinking water supply. For the past four years, I have studied the behavior of various pharmaceutical compounds in water. I began by focusing on the fluoroquinolones, a set of antibiotics commonly taken by both humans and animals. I studied their degradation under gamma irradiation, measured their rate constants with hydroxyl radicals and hydrated electrons, and identified several byproducts that are formed when they break down in solution. Then, I shifted to a set of three antidepressants, which are also widely utilized by patients. For this study, I focused on photochemical fate, attempting to understand the behavior of the compounds under natural sunlight rather than engineered treatment. Once again, I obtained degradation rates and identified reaction byproducts. This past summer, I had the opportunity to perform research at the University of Otago in Dunedin, New Zealand, through the NSF’s East Asia and Pacific Summer Institute. While I have traveled abroad before, this was the first time I was studying in a foreign country, and I felt apprehensive yet excited. Upon my arrival in the country, the Royal Society of New Zealand gave all the EAPSI participants a 3-day orientation, which included an introduction to the local culture, information on the research environment, and general tips on the New Zealand lifestyle. After this, I arrived in Dunedin and settled down in my apartment, ready and anxious to begin. My research at the University of Otago focused on enoxacin, a fluoroquinolone antibiotic. I utilized an ultraviolet light reactor to degrade the compound, and monitored the concentration as a function of time by high performance liquid chromatography. This enabled me to describe the degradation kinetics. I then repeated this process under several sets of conditions, in order to analyze the impact of various factors on the degradation rate. I discovered that hydrogen peroxide increases the rate of degradation, as does a combination of hydrogen peroxide and ferrous ions. This last condition, commonly known as the photo-Fenton reaction, is a common technique used to produce reactive oxidants that can be used to break down pharmaceuticals and other compounds. I also obtained a sample of sewage from the Dunedin wastewater treatment plant, in order to study the behavior of enoxacin in real-world conditions. In addition, I ran experiments to monitor the total organic carbon in the enoxacin sample during irradiation. Finally, I identified the byproducts formed during the irradiation process through mass spectroscopy and nuclear magnetic resonance spectroscopy. My research, however, was only a portion of my experience in New Zealand. I also had the opportunity to immerse myself in a foreign culture, meet the local people, and experience a lifestyle surprisingly different from my own. Besides giving me the opportunity to perform scientific research in a foreign university, EAPSI provided me with a chance to develop new collaborations with scientists from all over the world, and I hope to remain in contact with many of them as I progress through my career. This program has certainly been one of the highlights of my graduate education.

Agency
National Science Foundation (NSF)
Institute
Office of International and Integrative Activities (IIA)
Application #
1108352
Program Officer
Carter Kimsey
Project Start
Project End
Budget Start
2011-06-01
Budget End
2012-05-31
Support Year
Fiscal Year
2011
Total Cost
$5,700
Indirect Cost
Name
Santoke Hanoz B
Department
Type
DUNS #
City
Huntington Beach
State
CA
Country
United States
Zip Code
92646