The water sector is increasingly adopting more sustainable and efficient practices, with the ICARUS project, led by Acciona, at the forefront of this transformation. The project aims to recover secondary resources from wastewater treatment plants (WWTPs) and repurpose them in the construction industry, supporting the principles of the circular economy.
Historically, WWTPs have been focused on contaminant removal before discharging treated water into the environment. However, with the shift towards optimising resources and energy, there is growing recognition of their potential to become “biofactories”, generating valuable resources. The ICARUS project focuses on recovering cellulose, a material found in wastewater, particularly from products such as toilet paper. This cellulose can be upcycled into construction materials such as cement, asphalt, and concrete, helping to reduce the demand for new raw materials and the carbon footprint of the construction industry.
One of the key innovations of the project is the use of rotary band filters (RBF), which can recover up to 37% of the organic load and significant amounts of cellulose from wastewater. This system will be trialled and optimised in a pilot plant installed at the Sant Celoni WWTP in Barcelona. Additionally, the ICARUS project addresses the elimination of contaminants, such as microplastics and pharmaceuticals, ensuring that the recovered cellulose meets the necessary standards for use in construction.
The ICARUS project goes beyond cellulose recovery; it seeks to create synergies between sectors. By integrating resources recovered from the WWTP process into the construction industry, the project contributes to a closed-loop circular economy, promoting sustainability in both sectors. This innovative initiative will reduce waste, optimise energy use, and improve resource efficiency across industries, taking a significant step towards a more sustainable and circular future. (Full report in Spanish here)
Originally published in TecnoAqua, May 2025.
