STTR Phase I: Development of low-cost optical sensor for nitrate detection in agricultural soils and environmental waters

The broader impact/commercial potential of this project will be to help control nutrient contaminants in soil and water for the benefit of the world?s population, by providing sustainable access to safe drinking water. The estimated national economic cost of nitrogen pollution in drinking water is $19 billion annually, while the cost to freshwater ecosystems is $78 billion per year. Traditional water-quality monitoring practices are based on "grab-samples" that are sent for laboratory analyses that may take days to weeks to be completed. Similar traditional approaches are found in agriculture where excessive application of nitrate-based fertilizers may result in agricultural runoff that carries pollution to ground and surface water sources. The proposed high-performance, low-cost optical sensor technology will enable deployment of a dense real-time monitoring network in freshwater sources, water treatment facilities, and farms, and will gain a significant foothold in the $6.8B global water quality monitoring equipment market. In the event of natural disasters, integration of the proposed nitrate sensor will be useful in assessment of water quality in local water resources, providing communities with real-time information on water safety. This Small Business Technology Transfer (STTR) Phase I project focuses on the development of a non-dispersive infrared (NDIR) detector for real-time monitoring of nitrate concentration in water. This effort will combine nitrate-selective ion-exchange membrane technology with today's low-cost infrared (IR) components for the design of a new type of sensor targeting applications in aqueous environment. The proposed technology relies on infrared optical fibers for signal transmission. Currently, the use of commercial real-time optical nitrate sensors, based on ultra-violet (UV) absorption, is limited due to the optical interferences in the UV spectra related to the inorganic and organic substances, and reduced UV transmission caused by turbidity. The proposed proprietary IR technology is designed to overcome these shortcomings through implementation of smart membrane filtering. The instrument will provide high frequency data collection in dynamic aqueous environments with a wide sensitivity range (1 to 100 ppm). This technology can be further expanded for measurement of additional nutrients and contaminants, making it a robust tool for water quality assessment.