As of 2019, 43 million Americans did not have access to public water systems and relied on private wells. Indeed, a 2015 report by the United States Geological Survey, or USGS showed that 11-30 percent of residents in Louisiana got their water supply from private wells. The national average was 14 percent.
Unlike public water systems, these wells are not regulated and present an increased health risk from waterborne contaminants like pesticides, herbicides, and even sewage. In addition, because these wells are dug out of necessity due to lack of access to public utilities, those facing a health risk are also usually at a socioeconomic disadvantage.
This issue is at the heart of a National Science Foundation Partnerships for Innovation-Technology Translation, or PFI-TT, project by LSU Chemical Engineering Associate Professor Kevin McPeak and LSU Civil and Environmental Engineering Assistant Professor Samuel Snow. The pair are working with Troy Smith at Kingdom Technology Services in Houston. Smith has decades of experience in the UV water treatment business and will advise on the project.
What the project will do is develop a new water treatment system that simultaneously treats odorous water, recalcitrant organics (e.g., pharmaceuticals), and biological pathogens using ultraviolet, or UV, light and without the addition of chemicals. Existing solutions typically require multiple treatment systems that add complexities and costs.
“We have shared and complementary expertise with this light-driven technology,” said Snow in reference to his partnership with McPeak. “We will push the limits of our materials to engineer highly compact and efficient chambers that allow us to expose the water to as much ultraviolet light and the photoactive surfaces as possible. The process uses only oxygen dissolved in water, plus the UV light to transform the rotten-egg-smelling hydrogen sulfide into harmless, odorless products.”
In addition to the desired practical outcomes of this project, McPeak and Snow aim to advance the understanding of inhibiting agents in photocatalytic water treatment systems. This knowledge is critical in developing a robust photocatalyst for water treatment. Among the techniques they will employ in this project is the use of a scanning near field optical microscope, or SNOM, a one-of-its-kind piece of equipment awarded through an NSF MRI grant in 2020. The device’s unique nano-Fourier transform infrared spectroscopy capabilities will be utilized to probe and better understand fouling on the water’s photocatalyst surfaces with nanoscale mapping capabilities.