STTR Phase I: Safe Disinfection and Oxygen-Level Enrichment in Recirculating Aquaculture Systems (RAS) Using Singlet Oxygen

The broader impact of this STTR Phase I project is to address critical health, safety, cost and energy challenges in recirculating aquaculture system (RAS) disinfection. Growing high quality protein at larger scales cannot be done with current animal husbandry techniques without generating excessive greenhouse gas emissions. Intensive RAS technologies offer a viable alternative because they are capable of producing high quality protein with minimal impact on the environment. Protecting the health of the fish is one of the key limitations to a more rapid growth of this industry. This project will improve food production at scale. Furthermore, the proposed technology may be applied to drinking water. This STTR Phase I project will advance a technology for safe and low-energy bacteria disinfection in a recirculating aquaculture system (RAS) by using a durable, low-cost method to generate singlet oxygen, an excited-state form of molecular oxygen. Ozone and ultraviolet light are mainstay disinfectants in the fish farm industry, but they are expensive, energy-intensive and can be toxic to fish and personnel; motivating advances in safe, low-energy disinfection. Singlet oxygen is a powerful disinfecting agent lethal to pathogens and harmless to fish and humans. The primary innovation of this project allows singlet oxygen to be generated at high efficiency without contaminating the water as it is not persistent. This project will conduct engineering studies as a function of both chemical structure and mass transport of reactants and products. Detailed models will be developed to determine the appropriate dimensions of the disinfection system as well as understand the interactions between singlet oxygen and pathogens. These models will be the first to couple transport phenomena with absorption/desorption kinetics in this configuration for RAS. 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.