Grant: Alliance Grants

This proposal is a partnership between researchers at UBC, Acuva Technologies (a developer of UV LED photoreactor technology), and the First Nations Technical Services Advisory Group (TSAG) to research an innovative ultraviolet UV LED water treatment technology suitable for small drinking water systems (SDWS). UV LEDs are a promising radiation source for water disinfection because they are more stable, more compact, longer lasting, and environmentally friendlier than traditional mercury UV lamps. However, photoreactors designed to work with diffuse UV emission from lamps must be re-designed to work with directional, point-like emission of UV LEDs. UV LED photoreactors are illuminated by uniform, directional UV beams which are sensitive to shadowing due to particulates in the water. For SDWS without pre-filtration systems, turbid water is a common real-world operating condition which renders disinfection by UV LED technology ineffective. The goal of this work is to explore UV LED photoreactor designs that can work under real-world water treatment conditions that are typically found in small communities. The novel strategy to realize this goal is to use optically engineered materials to convert the point-like, directional emission from UV LEDs into uniform, diffuse light distributions. We have evidence that provides a recipe for creating materials to diffuse and guide UV light and will explore the real-world implementation of such a material for operation at UV frequencies using finely structured, thin-film polymers molded by techniques amenable to mass manufacturing. Such an approach would be particularly suited for SDWS, as it would, in principle, be effective for sterilizing un-filtered water. The research will be conducted in consultation with SDWS operators and tested under conditions representative of SDWS, providing the first validation studies of UV LED water sterilization technology specifically for small communities.