Opportunity: nitrate is currently the most prevalent groundwater pollutant in northern america, primarily from agricultural activities and changing nitrogen input to the land surface

In the US, over 7 million americans drink water from community water systems (CWS) that contain nitrate (NO3-) at concentrations exceeding the maximum contaminant level (MCL). The go-to technologies for nitrate treatment from cwss produce highly concentrated nitrate brine residuals and are limited by expensive brine disposal and management options. Further, more than 35 million acres of sub-surface drained land exist in the US, and no technology has established a significant market share that removes nitrate from agricultural drainage. Based on the scale of nitrate contamination in community water systems and the growing need to reduce nitrogen load from tile drainage, the total addressable market for nitrate removal is sizable.proposed solutionthe core technology developed through this sbir project willbe a fluidized bed photocatalytic reactor to denitrify agricultural wastewaters and nitrate-contaminated community water systems. The proposed technology could be powered using renewable electricity, will generate no nitrate-brine residuals, and will produce hypochlorite that can be used as a disinfectant fornitrate-treated waters.anticipated benefits. We anticipate the proposed technology to be superior for nitrate recovery compared to incumbent technologies both from an economic and environmental standpoint. Potential benefits include:• decreased water treatment cost and environmental impact - the proposed unit transforms nitrates to inert nitrogen, enabling US to sidestep brine disposal and concentrate management challenges associated with incumbent systems. Brine disposal cost ($1.2/M3) can itself be equal to or more than water treat-ment cost and could constitute a significant environmental burden. The CO-production of hypochlorite eliminates the need to store and transport hazardous chemicals such as chlorine gas, otherwise needed for disinfection, further reducing the operation and maintenance cost.• reduced carbon emissions and potential for distributed treatment infrastructure - the led in the fluidized photocatalytic reactor can be powered using renewable electricity, thereby reducing energy consumption, carbon emissions while enhancing flexibility. The proposed pathway also provides the opportunity to make up for the intermittency of renewables, for example, by combining sunlight in the daytime with nighttime grid power led supplementation. The proposed technology is well suited for off-grid locations since the unit can be coupled to a solar cell or a wind farm.• improved water quantity and quality - removal of nitrates from agricultural return flows would render water to be reused for agricultural activities.