Belgian water treatment company Aquafin aims to give wastewater from sewage a swift boost. The potential is vast. By reusing heat from wastewater, it would be possible to heat up to 400 large buildings in Flanders.
Most of our household water flows through the sewer system to a wastewater treatment plant. There, everything such as food scraps, soap, toilet paper, and faeces is removed from the water. For the most part, the lukewarm cleaned water continues to be discharged into a river or the sea. Only a few projects currently recover heat from wastewater to heat buildings, including Aquafin's headquarters in Mechelen. Furthermore, apartment buildings in Mechelen and a swimming pool and sports complex in Sint-Niklaas will be heated using wastewater. By January 2025, we aim to have a comprehensive overview of all sewers in Flanders suitable for heat extraction. Heat supply will then be directed to projects with the greatest impact to maximise sustainability and contribute to climate targets. This will render fossil fuels obsolete. As a result, it is expected to save up to 40,000 tonnes of CO₂ across Flanders.
Technically summarised, the process is as follows: a heat exchanger extracts an average temperature of 18°C from the wastewater treated by the plant. The heat is then increased by a heat pump to reach 75°C. Through the grid, the heated treated water returns to heat buildings and supply tap water.
