Stuttgart, 15.11.2022 – Germany’s almost 10,000 municipal wastewater treatment plants consume around 4,400 gigawatt hours (GWh) of electricity per year, which makes them one of the largest electricity consumers. This is equivalent to the electricity needs of 900,000 four-person households. Moreover, the greenhouse gases nitrous oxide and methane are produced during wastewater treatment and contribute significantly to the plant’s total emissions. It is estimated that wastewater treatment plants emit about as many greenhouse gases as the global aviation industry. But there is good news for this sector. With their new “Emission Control” system, the Stuttgart-based technology company Variolytics can reduce up to 50% of the total emissions of wastewater treatment plants. Furthermore, through an AI-based control system, the wastewater process is dynamically controlled and not only reduces greenhouse gases, but also energy and chemical consumption.

For biological wastewater treatment using the activated sludge process, tanks are gassed with oxygen. If the bacteria in the basin receive too little oxygen, they cannot optimally decompose the dissolved organic contaminants. However, too much gassing does not lead to better degradation, but only to higher energy costs for the plant operators. Another complicating factor is that both “too little” and “too much” gassing results in nitrous oxide. This gas is particularly greenhouse-active, 273 times more compared to CO2. Finding the “golden mean” and avoiding the production of this gas is therefore critical. Variolytics’ patented measurement technology monitors the formation of climate-damaging gases in the aeration basins of the sewage treatment plant and helps to reduce them. For this purpose, the gassing, but also other “adjusting screws”, of the aeration tanks are instantly adjusted by an intelligent control system for an optimal microbial decomposition of the organic matter on the basis of the measured values.

The EU has set itself the goal of achieving climate neutrality by 2050. In Germany, the Bundes-Klimaschutzgesetz (Federal Climate Protection Act) of 12 December 2019 came into force (BGBl.IS.2513), which provides for a reduction in greenhouse gas emissions, by a total of 55% by 2030 compared to 1990. Wastewater treatment is included in the Waste Management and Miscellaneous sector and has to reduce its emissions to 5 million tonnes of CO2 equivalents by 2030. With its technology, Variolytics offers an effective way to achieve these goals.

The seed investment from HTGF, FTTF and business angels is a big step towards scaling for Variolytics. In the coming year, Variolytics wants to expand its production and grow strongly in the European market. From currently 9 employees, the team wants to grow to 12 in the next months. The start-up wants to put a special focus on the areas of production, service/maintenance and sales.