Miles Carlson, “”Chlorine Leaching in PVC: Concerns for Replacing Lead Pipes with Plastic Piping””
Mentor: Laodong Guo, Freshwater Sciences, Freshwater Sciences (School of)
Poster #58
As efforts to remove Lead Pipes have increased after Infrastructure bills under the Biden Administration provided funding to relevant projects and 2024 EPA rule changes regarding permitted Lead piping, it has become more relevant to examine the safety concerns of the pipes replacing lead. Polyvinyl chloride (PVC) is widely used in drinking water distribution systems due to its durability, low cost, and resistance to corrosion. However, concerns have arisen regarding the potential release of dissolved organic matter (DOM) and additives from PVC materials, particularly under the influence of disinfectants such as chlorine. Chlorine, often coming from the use of Sodium hypochlorite, can interact with PVC to leach DOM from microplastics and potentially form harmful disinfection byproducts. It is therefore important to investigate the DOM released and its characteristics to understand potential public health risks with widespread adoption of PVC piping. This study aims to investigate the influence of different chlorine concentrations on the release and characteristics of DOM from PVC microplastics under different leaching conditions, including high temperatures and high UV exposure. The optical and fluorescence properties of the leached DOM were analyzed using spectroscopic techniques, with a focus on characterizing chromophoric dissolved organic matter (CDOM). Changes in specific ultraviolet absorbance (SUVA254), an indicator of aromaticity, and spectral slope (S275−295), which provides insight into DOM molecular weight, during leaching experiments have been monitored. Examining the changes in these DOM properties will allow us to better understand how PVC microplastics interact with common chlorine disinfectants. Our findings here can contribute to getting a better understanding of the impacts widespread PVC pipe use could bring on water quality and our water drinking infrastructure.