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Analysis of Particulate and Nanoparticles In Drinking Waters: Analytical Techniques, Interpretations and Considerations
Citation:
Harmon, S., D. Lytle, C. Formal, AND E. Dore. Analysis of Particulate and Nanoparticles In Drinking Waters: Analytical Techniques, Interpretations and Considerations. AWWA Virtual Summit Water Quality and Infrastructure, Cincinnati, OH, December 08 - 10, 2020.
Impact/Purpose:
This presentation addresses the analysis of particles found in drinking water distributions systems. Particles can cause nuisance complaints and can possibly affect consumer’s health. Presented here are an array of analytical techniques including scanning electron microscopy with energy dispersive spectroscopy, transmission electron microscopy with energy dispersive spectroscopy and electron diffraction, x-ray diffraction and zetasizer. Also, address are various sample preparation techniques, and some advantages and limitations of each method. The significance of this work is it gives a general understanding of possible avenues to pursue when contemplating particulate analysis in drinking waters. Possible interested parties would be water utilities, contract laboratories, and other water researches.
Description:
Reducing lead in drinking water is a critical public health objective. The role of particulate lead release from leaded plumbing materials has long been considered important, however, tools commonly employed by the water industry to identify particles have largely been restricted to fractionation by filtration. In recent high-profile drinking water lead events in Flint, MI, and Newark, NJ, particulate lead was a large contributer to lead release, and it is thought that particulate lead related issues are largely uncharacterized. Determination of the extent of lead particle releases and accurately identifying the nature of lead particles is necessary to understand the mechanism(s) of lead release and most effective remediation approaches. Given the research and practical need to better characterize lead particles, the objective of this work is to discuss analytical techniques and corresponding preparation methods employed by the EPA ORD’s Advanced Materials & Solids Research Core (AMSARC) research group to study particles in drinking water. Specifically, methods including particle fractionation by filtration particle sizing and charge measurements based on dynamic light scattering principles, low vacuum scanning electron microscopy with energy dispersive spectroscopy LV (SEM-EDS, field emission scanning electron microscopy with energy dispersive spectroscope (FESEM EDS), transmission electron microscopy with energy dispersive spectroscopy (TEM EDS), and powdered X-ray diffraction (XRD) will be discussed. Analyses were performed on particles (primarily lead) generated in research studies or recovered from full-scale drinking water distribution systems. Approaches for separating particles from water and preparing particles for analyses, when necessary, will be compared. Each solid analysis approach has different working fundamentals, and strengths and weaknesses that will be discussed in some detail and analysis of actual samples will be used to illustrate differences. For sample, although FESEM can identify nanoparticles (<100 nm), the greater resolution of TEM is necessary to discern lattice details and for crystalline phase identification by electron diffraction.