I-Corps: A fluorescence sensor for early detection of nitrification in drinking water

University Of Arkansas, Fayetteville AR

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the development of a fluorescence sensor system for early detection of biological ammonia oxidation in water. Biological ammonia oxidation can degrade drinking water quality and, in the absence of corrective actions, lead to growth of bacteria that may sicken consumers. Biological ammonia oxidation is presently diagnosed by analysis of multiple chemical species following grab sample collection at several locations within a drinking water distribution system, which is a time-consuming and labor-intensive process. The proposed fluorescence sensor system would automate this process by detecting products released by bacteria prior to the degradation of drinking water quality. Use of this proposed sensor system may facilitate early detection of biological ammonia oxidation, allowing for corrective actions to be applied in a timely manner to maintain high quality drinking water at the tap. Other potential applications include hospitals and medical facilities that remove drinking water disinfectants for kidney dialysis and other therapeutic uses, and beverage manufacturers that remove disinfectants due to taste and odor concerns. This I-Corps project is based on the development of a fluorescence sensor system for early detection of biological ammonia oxidation in water. Research demonstrated that fluorescence intensities at specific wavelength pairs measured with a laboratory-grade benchtop fluorometer revealed the presence of soluble microbial products released by bacteria into water prior to biological ammonia oxidation. To be useful in practice, however, these fluorescence measurements need to be made in real-time at multiple locations within a drinking water distribution system as opposed to in a laboratory following sample collection. The proposed sensor system would allow for continuous real-time fluorescence measurements and consists of a lamp to generate excitation light, optical filters to generate the appropriate wavelengths of light, and an emission detector to collect the fluorescence spectra. A companion data-processing algorithm and graphical user interface is used to make comparisons of fluorescence signals to an established threshold level in which biological ammonia oxidation is not occurring. Hospitals and beverage manufacturers that remove disinfectants from drinking water also may leverage this sensor for other applications. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.