Demo 5 – Modular and compact wastewater and rainwater systems for high-density urban areas

Description

Raw wastewater will be pumped from the centralised sewer for treatment in a process chain consisting of: 1. different pre-treatment units, 2. two modified compact prefab elevated wetland modules with 2,5 m² filter area each, and 3. downstream UV disinfection. The solids will be returned to the sewer after solid-liquid separation. The elevated construction allows for space use optimisation and versatile urban applications, e.g., on paved surfaces, rooftops, and carports. The system design builds on previous designs of RPTU . Different mixtures of filter materials, such as biochar and iron-containing expanded clay, will be used in combination with downstream disinfection to enhance the removal of both organic micropollutants and pathogens. The treated water and harvested rainwater from roofs will be used to irrigate urban greenings while providing nutrients (fertigation).

Demo 5 showcases how decentralised systems can complement existing centralised wastewater infrastructure, enhancing resource efficiency and climate resilience. The systems will be investigated for water reuse, ensuring compliance with the EU Regulation 2020/74. The approach will also integrate real-time monitoring and control systems to optimise rainwater harvesting (UIBK). Conventional stormwater management often suffers from inefficiently managed storage capacities due to a lack of control options and integrated sensors.

A smart rainwater harvesting module with an approximate capacity of 5 m³, based on the Smart Rain Barrel concept, will be demonstrated.. The Smart Rain Barrel concept is an IoT-based system equipped with a water level sensor and a remotely controllable discharge valve, allowing it to release stormwater before precipitation events. The control strategy will be further developed and adapted to the real-world conditions at the demo site.