Greywater and blackwater can be separated with retrofitting measures in existing buildings. Greywater can be treated using innovative nature based solutions for indoor application in multi-level green walls with minimum energy cost (<1.5kWh/m3) and disinfected using commercial O3/UV systems for >90% water reuse.
Water meters at household and building level can show the amount of water reuse for toilets recharge or irrigation. On the other hand, rainwater can be also pre-treated with nature based solutions on the façade or roof area. Here, we will have also a loss through evapo-transpiration, potentially obtaining >95% rainwater reuse or minor in dry climates locations with low rainfall patterns.
The service model will consider a payment fee per m3 water treated and reused. This solution will be developed and demonstrated at laboratory and semi-pilot scale prior to implementation at large scale (Demo buildings). Operating parameters obtained in lab scale tests with nature based solutions will allow the optimisation of O3/UV technologies as well as the proper dimensioning of nature based solutions for final integration.