Date(s) - 20 Sep 2017
1:10 PM - 2:00 PM
3043 ECpE Building Addition
Speaker: Amin Gorji, ECpE Graduate Student
Adviser: Nicola Bowler
Title: Dielectric Spectroscopy of Low-Concentration Aqueous Solutions of Contaminant Ions
Abstract: The flow of nitrate ions into the Gulf of Mexico is a major environmental concern in the United States. Presence of excess of these ions causes explosive plant growth which uses up available oxygen in the water, leaving areas unable to support aquatic life. Furthermore, the excessive concentration of such ions in drinking water poses a threat to human health. The efflux of ions from agricultural lands in Iowa has been estimated to be about one quarter of the nitrate that the Mississippi river delivers to the Gulf of Mexico which has been a topic of recent controversy between the Des Moines Water Works and three Iowa counties. Assessing the effectiveness of management strategies to control the ions’ efflux is hampered by the lack of affordable, effective, and in-field nitrate monitoring systems. Thus the need for low-cost and real-time sensing becomes critical for complete monitoring. By measuring the dielectric properties of liquid, we can infer properties that can influence the molecular structure, such as ion concentration. In this work, environmentally-relevant electrolyte solutions of nitrate, chloride, and sulphate ions are characterized in terms of their conductivity and high frequency dielectric properties. The ion-specific responses are presented and the planned development of real-time sensors, based on these results, is discussed.