Purdue Calumet Professor & Alumnus Produce U.S. Patent

George Nnanna

Professor George Nnanna

Efforts by Purdue University Calumet Professor of Mechanical Engineering George Nnanna and engineering alumnus Hasnain Jalal have produced a U.S. patent for the university and its Water Institute. Nnanna, director of the Water Institute, head of the Department of Mechanical Engineering and a Crown Point resident, and Jalal of Chittagong, Bangladesh, developed an oxazine-based Optical Sensor for online continuous detection of ammonia contaminants in water delivery systems.    

 Lethal to aquatic organisms, humans

“Ammonia is a ubiquitous chemical with a multitude of agricultural, domestic and industrial purposes,” Nnanna said. “However, a small amount of ammonia can be lethal to aquatic organisms, and prolonged exposure at low concentration is dangerous to humans. Given these risks, reliable detection is of the utmost importance in protecting humans and wildlife.” Developed at the Water Institute, the Optical Sensor uses optical fibers that are ideal for In-situ online monitoring of water delivery systems. The sensor reduces the need for batch-sampling in contaminant detection.  

 Effective in stagnant and moving water

Nnanna added that the sensor is effective in both stagnant and moving water, has instantaneous response times, and has ammonia detection limits of 1.4 parts per million (ppm) in stagnant water and 3.9 ppm in moving water. Nnanna has served Purdue Calumet since 2002. He holds a baccalaureate degree from Texas Tech University and master’s and doctoral degrees from the University of Texas at Arlington.