Water is one of the most valuable resources on our planet. The challenges of providing clean water are increasing as global water consumption rises. To comply with legal requirements, mechanical, chemical and biological processes are used in water treatment to remove contaminants or reduce their concentration. Wastewater treatment plants (sewage treatment plants) in particular are used to treat and purify contaminated water. Gases such as oxygen, carbon dioxide or ozone can make a significant contribution to purification in the various treatment stages. However, it is also important in industrial wastewater treatment to develop an optimised treatment and plant concept so that the water can be treated reliably and cost-effectively.