On the way to the cost-efficient, climate-neutral and AI-controlled wastewater treatment plant of the future

In addition to the main objective of wastewater treatment, wastewater treatment plant operation faces many other challenges. These include the reduction of energy and resource consumption as well as the minimisation of greenhouse gas emissions.

The overall aim of the joint project is to develop a dynamic, generally applicable optimisation tool for wastewater treatment plants that will enable operators to meet current and future challenges with more efficient, emission-minimised and resource-saving operation. This is to be achieved by linking biochemical process models and artificial intelligence with advanced online measurement technology. The intelligent utilisation of the recorded data sets enables measured values to be predicted, expanded and checked for plausibility. Optimisation strategies are determined with regard to climate and energy efficiency using self-learning algorithms and a digital twin of the respective wastewater treatment plant.

The central aspect of the project for the Ruhrverband is the measurement and minimisation of greenhouse gas emissions. These are caused in wastewater treatment in two ways. On the one hand, they are caused indirectly, for example by electricity consumption for aeration. On the other hand, greenhouse gases are formed directly by biological processes, whereby methane (CH₄) and nitrous oxide (N₂O) in particular are considered due to their high climate relevance. As part of the joint project, the focus is on nitrous oxide, which is mainly produced in the aeration tank. The investigations are being carried out at two wastewater treatment plants of the Ruhrverband.

The aim is to estimate the total emissions, whereby the emissions are calculated by measuring the N₂O formed in the liquid phase. Additional measurement campaigns are carried out to validate the calculation. Gas bonnets are used to measure the N₂O emissions in the gas phase. In addition, FTIR measurements are carried out by LANUV, in which N₂O and CH₄ emissions are also measured above the aeration tanks.

To increase the accuracy of the Ruhrverband's carbon footprint, the results will then be transferred to the Ruhrverband's other wastewater treatment plants and general recommendations for minimising emissions will be developed.