UV Resonance Raman Spectroscopic Detection of Nitrate and Nitrite in Wastewater Treatment Processes

Abstract

The 204- and 229-nm excited UV resonance Raman spectra of wastewater solutions containing sodium nitrite and nitrate were measured in the concentration range 7 microM to 3.5 mM (0.1-50 ppm nitrogen). The other chemical species present in wastewater do not interfere with Raman measurements of NO2-/NO3- bands. We observe detection limits of < 14 microM (< 200 ppb) for both NO2- and NO3-. UV resonance Raman spectroscopy appears to be an excellent tool for on-line monitoring of NO2-/NO3- in wastewater for the real-time control of water treatment plants.