IMPROVE FOOD SAFETY OF HYDROPONICALLY GROWN FRESH PRODUCE USING PHOTOCHEMICALLY TREATED RECYCLED WASTEWATER

<b>Project Methods</b><br> The project will:(1) Characterize the performance of UV photolysis of persulfate on the removal of foodborne pathogen from recycle wastewater for irrigation. (2) Establish a modeling framework to predict pathogen risks in hydroponically grown fresh produce and improve food safety. (3)Enhance the PD's knowledge in pathogen control and develop new expertise in food safety.The experimental investigation will utilize both conventional and cutting-edge analytical chemistry tools to examine the pathogen disinfection kinetics of the efficacy of different reactive radicals from persulfate photolysis for advanced water reuse treatment. Photolysis experiments will be conducted both in bench-scale photochemical reactors in quartz test tubes using a merry-go-round photochemical reactor (ACE Glass Inc.). A fixed-wavelength low-pressure UV lamp at 254 nm (typical in water treatment) will be placed in the center of the reactor to generate a range of radical species. Medium pressure UV bulbs (200-400 nm) will be considered as an alternative light source.Coliphage MS2 (ATCC 15597-B1) will be used as virus surrogate and propagated using E. coli. – 3000 (ATCC 15597) as host. Briefly, MS2 will be inoculated into 20 mL actively growingE. colihost suspension. The host-associated MS2 suspension was then centrifuged to remove the bacterial cells and debris. The concentration of MS2 in water samples was titrated by the double agar layer method. The development of pathogen transport model will be embodied in a system of ordinary differential equations that also incorporated plant growth, transpiration rate, viral attachment and detachment to culture media, viral decay, and plant barrier effects. Model parameters will be obtained both from the literature and through fitting the model to experimental data. In addition,virus filtration and recovery methodology will follow established standard procedures from existing literature.