I-Corps: Chemical-Free Advanced Oxidation Water Treatment System

The broader impact/commercial potential of this I-Corps project is the development of a chemical-free, ultraviolet (UV) light-driven water treatment system for the water re-use market. The cost of implementing UV light-driven water disinfection is often a barrier to its utilization on smaller scales or in more vulnerable communities. By improving the affordability of UV light-driven advanced oxidation processes (AOPs), it may be possible to implement this technology in developing communities, especially for the disinfection of parasites like Cryptosporidium and Giardia, which pose a significant public health threat.

By replacing chlorine-based oxidants, the proposed device may reduce harmful disinfection byproducts such as trihalomethanes (THMs). Research suggests that consuming THMs in drinking water may elevate the risk of certain cancers and result in adverse reproductive outcomes. More comprehensive implementation of UV-AOPs also may lead to the degradation of many emerging contaminants, including 1,4-dioxane, antibiotics, endocrine disruptors, and (potentially) SARS-CoV-2.

This I-Corps project is based on the development of an immobilized photocatalyst with a high effective surface area, low mass transport limitations, deep UV penetration, and long-term chemical, mechanical, and thermal stability. The proposed technology has been implemented in a proof-of-concept reactor and shows that the technology will degrade various chemical contaminants under UV light illumination in a matter of seconds.

The primary figure of merit for judging the economic viability of UV AOPs is the electrical energy per unit order (EE/O), i.e., the amount of electrical energy required to reduce the concentration of a target pathogen or chemical contaminant by one order of magnitude (90%). While EE/O is largely dependent on the water quality, target contaminant, and reactor design, UV light disinfection systems with EE/O values below 10 kWh/m3 are generally considered commercially viable. The proposed technology can achieve an EE/O for a model contaminant (Rhodamine B) of <0.6 kWh/m3 for several days without a drop in performance.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.