Ammonia Point Sensor for Intensive Livestock Operations

This Phase II program will produce a sensitive, reliable and cost-effective monitor for ammonia emissions in confined animal feeding operations (CAFOs). CAFOs have become a major form of animal production. There is increased concern over emissions from confinements houses and health effects on workers and animals. The CAFO industry needs reliable monitoring solutions to support manure management and sustain competitiveness. In Phase I, we demonstrated a unique colorimetric sensor system, capable of monitoring ammonia continuously from less than 1 ppm to hundreds of ppm. Maximum sensitivity was between 0-50 ppm NH3, but linear response with reduced sensitivity up to 300 ppm was found. Negligible or minor interference from carbon dioxide, methane and hydrogen sulfide were observed. The sensor functioned well in high humidity and dusty environments. We demonstrated sensing with breadboarded components comparable to those to be used in Phase II. 1-2 ppm ammonia was readily monitored, with positive response in under 2 s. Detection limits were on the order of 0.5 ppm. In Phase II we will complete polymer sorbent film and prototype development. A field-testable prototype unit will be fabricated and tested in the lab and under live CAFO conditions in cooperation with USDA ARS staff in Fayetteville, AR.