Nitrite sensing in urine nitrification reactor with in-situ UV-Vis spectrometry

This work evaluates UV-Vis spectrometry as a tool to estimate nitrite in a continuously operated urine nitrification reactor. The need for such a tool originates from the sensitive urine nitrification systems which need control for stable operation. At this time, the LASSO model identification method which selects a small number of UV-vis absorbance wavelengths proves sufficient to capture the most important dynamics of the nitrite concentration. This is likely sufficient for stabilizing control. Further investigations aim at evaluating whether the trueness and precision can be brought to a level that would permit on-line process optimization as well.