At HRSD, the regional wastewater treatment utility that serves southeast Virginia, process engineers and researchers are working with the development of novel processes for nutrient removal from wastewater.
One of the primary focuses is the application of the deammonification process directly in the mainstream. Currently, HRSD is operating a fully integrated pilot process and as part of the instrumentation, the N2O Wastewater Sensor from Unisense Environment, Denmark, is used for online monitoring of dissolved N2O.
N2O production is tightly linked to the level of oxygen (O2) and nitrite (NO2 -), and due to these well established correlations, the N2O sensor provides a unique and valuable parameter. Together with other online parameters, the engineers can monitor and control the main deammonification substrates, ammonium (NH4 +) and nitrite, and also the bacterial selection process needed to maintain the mainstream deammonification.