Poster Title

An approach to monitoring reactions that could improve the quality of drinking water [Hybrid Poster 3-A]

Grade Level at Time of Presentation

Senior

Institution

Western Kentucky University

KY House District #

62

KY Senate District #

17

Department

Chemistry

Abstract

Recent studies have shown that biologically harmful chemical pollutants are present at increasing concentrations in wastewater. Although wastewater treatment facilities are effective in the removal of solid wastes and bacterial contaminants, a variety of harmful chemical pollutants are able to pass into drinking water. This problem is especially evident in Kentucky, where pesticides from farm runoff and pharmaceutical waste from hospitals frequently enter wastewater. Although there are several proposed technologies which could eliminate these pollutants, they rely on chemical reactions which are not well-understood. Raman spectroscopy is a useful tool for monitoring reactions in real time, 100 times quicker than conventional methods of analysis, allowing identification of short-lived intermediate species which are important for developing a comprehensive reaction mechanism. However, Raman spectroscopy has some disadvantages. It is not a very sensitive technique, and although it is good for detecting chemical changes, it is unreliable for accurately tracking the change in the concentration of pollutants as time progresses. Here, gold nanoparticles were used to enhance sensitivity and thus allow the technique to study a broader range of pollutants. Additionally, more accurate monitoring of concentration changes as a function of time were made possible by introducing an internal standard as a point of reference. The use of nanoparticles to increase sensitivity presents an additional issue because nanoparticles tend to aggregate together when subjected to conditions necessary to monitor reactions, and thus signal diminishes as a function of time. This was addressed by introducing a secondary capping agent which stabilized growing nanoparticle clusters and prevented them from aggregating to the point of signal loss. Overall, this work serves to broaden the selection of pollutants which can be studied using Raman spectroscopy, and thus adds to our tools for ensuring the safety of new technologies in wastewater treatment.

This document is currently not available here.

Share

COinS
 

An approach to monitoring reactions that could improve the quality of drinking water [Hybrid Poster 3-A]

Recent studies have shown that biologically harmful chemical pollutants are present at increasing concentrations in wastewater. Although wastewater treatment facilities are effective in the removal of solid wastes and bacterial contaminants, a variety of harmful chemical pollutants are able to pass into drinking water. This problem is especially evident in Kentucky, where pesticides from farm runoff and pharmaceutical waste from hospitals frequently enter wastewater. Although there are several proposed technologies which could eliminate these pollutants, they rely on chemical reactions which are not well-understood. Raman spectroscopy is a useful tool for monitoring reactions in real time, 100 times quicker than conventional methods of analysis, allowing identification of short-lived intermediate species which are important for developing a comprehensive reaction mechanism. However, Raman spectroscopy has some disadvantages. It is not a very sensitive technique, and although it is good for detecting chemical changes, it is unreliable for accurately tracking the change in the concentration of pollutants as time progresses. Here, gold nanoparticles were used to enhance sensitivity and thus allow the technique to study a broader range of pollutants. Additionally, more accurate monitoring of concentration changes as a function of time were made possible by introducing an internal standard as a point of reference. The use of nanoparticles to increase sensitivity presents an additional issue because nanoparticles tend to aggregate together when subjected to conditions necessary to monitor reactions, and thus signal diminishes as a function of time. This was addressed by introducing a secondary capping agent which stabilized growing nanoparticle clusters and prevented them from aggregating to the point of signal loss. Overall, this work serves to broaden the selection of pollutants which can be studied using Raman spectroscopy, and thus adds to our tools for ensuring the safety of new technologies in wastewater treatment.