Electroanalytical Sensing of Copper in Drinking Water Matrices
Presenter: John Emerson Faculty Sponsor: Sean T. McBeath School: UMass Amherst Research Area: Environmental Engineering Location: Poster Session 5, 3:15 PM - 4:00 PM: Room 163 [C30]
Large-scale efforts to provide safe drinking water to the general public are crucial and further measures must be taken to prevent heavy metal pollution, such as copper. However, this proves to be a particularly challenging problem since heavy metals are introduced to water after treatment through aged distribution infrastructure, therefore requiring compact, low-cost sensing tools for individual households. This study seeks to develop and optimize an electrochemical sensor for trace level copper detection and quantification. Using a novel 3-in-1 electrode configuration housing a reference, counter, and boron-doped diamond (BDD) working electrode on a single chip, anodic stripping voltammetry (ASV) and differential pulse voltammetry (DPV) were investigated as combined electrochemical techniques for copper sensing. The effect of key ASV/DPV operating conditions, such as electrochemical deposition potential and time, were examined to improve sensor sensitivity and accuracy. As preliminary benchmarking, ASV/DPV parameters using a polyetheretherketone (PEEK)-housed BDD were determined to be 15 min deposition at -1.4 VAg/AgCl. These results provide an informed starting point for work with the 3-in-1 electrode assembly. Currently, 3-in-1 sensor optimization is being performed, with the goal of reducing deposition time while maintaining strong and repeatable signals. Upon establishing these operating conditions, we will yield calibration curves and evaluate accuracy and sensitivity, including establishing the sensor’s limits of detection and quantification. Future tests will include samples containing organic contaminants, to simulate real-world water conditions. Overall, ASV/DPV utilizing 3-in-1 BDD electrodes show promise as a cost-efficient and precise copper sensor in drinking water matrices.
Effect of Natural Organic Matter (NOM) Size on Reactivity and Disinfection Byproduct (DBP) Formation Potential
Presenter: Hannah Steinbrecher Faculty Sponsor: Sean T. McBeath School: UMass Amherst Research Area: Environmental Engineering Location: Poster Session 5, 3:15 PM - 4:00 PM: Room 163 [C31]
Disinfection byproducts (DBP) are compounds found in drinking water that can be carcinogenic. DBPs are formed when natural organic matter (NOM) reacts with chlorine, a common disinfectant used in drinking water treatment. While effective treatment strategies exist, none completely remove NOM from drinking water. There are several known factors impacting NOM reactivity and DBP formation, including pH and ion concentrations. However the effect of other NOM characteristics on DBP formation, such as size, is yet to be fundamentally understood. Our research seeks to understand whether NOM size affects DBP formation potential. NOM samples were prepared at known concentrations of 1, 5, and 10 mg/L (ppm) and analyzed for two regulated categories of DBPs, trihalomethanes (THMs) and haloacetic acids (HAAs), to gain a comprehensive baseline. NOM characteristics were also quantified, including size exclusion chromatogram (SEC) to divide known samples by molecular weight into two fractions: >10 and <10 kDa. The resulting DBP species and concentrations were compared to the baseline findings. We hypothesized that larger NOM fractions would have a greater effect on DBP formation due to the greater surface area, allowing for more sites for DBP formation reactions to occur. Preliminary results confirm that increasing concentrations of organic matter increase DBP formation. Ongoing toxicological analysis will evaluate the relative health effects of the different DBP species preferentially formed by disinfection for different size fractions. These findings aim to inform prioritization of treatment strategies to mitigate DBP formation and regulations.
