A Fluidized Bed Photocatalytic Reactor for Nitrate Conversion

Project SummaryOpportunity: Nitrate is currently the most prevalent groundwater pollutant in Northern Americaprimarily from agricultural activities and changing nitrogen input to the land surface. In the USover 7 million Americans drink water from community water systems (CWS) that contain nitrate- (NO ) at concentrations exceeding the maximum contaminant level (MCL). The go-to3 technologies for nitrate treatment from CWSs produce highly concentrated nitrate brine residualsand are limited by expensive brine disposal and management options. Further more than 35million acres of sub-surface drained land exist in the US and no technology has established asignificant market share that removes nitrate from agricultural drainage. Based on the scale ofnitrate contamination in community water systems and the growing need to reduce nitrogen loadfrom tile drainage the total addressable market for nitrate removal is sizable.Project Objectives: The main technical objective is to demonstrate the feasibility of a highlyefficient photocatalytic unit for the sustainable removal of nitrates from waste waters at a costlower than incumbent technologies. To achieve this goal the team will design novel particulate- type photocatalytic heterostructures that will reduce nitrates to nitrogen upon illumination whileco-generating hypochlorite as a disinfectant. The team will also investigate the nitrate conversionmechanism of synthesized photocatalytic heterostructures and use the results to optimizephotocatalyst formulations further. The optimized photocatalytic heterostructures will then betested in a lab-scale fluidized bed reactor with different feed water chemistries. The final goal forthis Phase I project would be to achieve nitrate removal efficiencies exceeding 75% and stabilityexceeding 100 hours in accelerated testing conditions.Anticipated Results. At the end of Phase I Pani Clean Inc will have a small lab-scale nitratetreatment unit with nitrate conversion efficiencies exceeding 75% no brine disposal issues andcost less than $1.2 per 1000 gallons of treated water a four-to-five-fold decrease compared to theincumbent technologies.Potential Commercial Applications. The 1706 community water systems (CWS) experiencingrecent violations of nitrate levels primarily from agricultural practices represent the immediatelyaddressable market. The near-term application would be to treat nitrates at the edge-of-field andas POU nitrate treatment systems for individual residences with nitrate-contaminated private wells.